Author(s) ID,Title,Year,DOI,Link,Abstract
"7003266200;6602378790;","Models-3 Community Multiscale Air Quality (CMAQ) model aerosol component 1. Model description",2003,"10.1029/2001jd001409","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0142203073&doi=10.1029%2f2001jd001409&partnerID=40&md5=cae729821e642a6f10c04cbd1eebf3aa","The aerosol component of the Community Multiscale Air Quality (CMAQ) model is designed to be an efficient and economical depiction of aerosol dynamics in the atmosphere. The approach taken represents the particle size distribution as the superposition of three lognormal subdistributions, called modes. The processes of coagulation, particle growth by the addition of mass, and new particle formation, are included. Time stepping is done with analytical solutions to the differential equations for the conservation of number, surface area, and species mass. The component considers both PM2.5 and PM10 and includes estimates of the primary emissions of elemental and organic carbon, dust, and other species not further specified. Secondary species considered are sulfate, nitrate, ammonium, water, and secondary organics from precursors of anthropogenic and biogenic origin. Extinction of visible light by aerosols is represented by two methods: a parametric approximation to Mie extinction and an empirical approach based upon field data. The algorithms that simulate cloud interactions with aerosols are also described. Results from box model and three-dimensional simulations are exhibited."
"7101825560;","The cumulus parameterization problem: Past, present, and future",2004,"10.1175/1520-0442(2004)017<2493:RATCPP>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-3843138534&doi=10.1175%2f1520-0442%282004%29017%3c2493%3aRATCPP%3e2.0.CO%3b2&partnerID=40&md5=d58ee80a9a41ee6439e158b4aa94b4ea","A review of the cumulus parameterization problem is presented with an emphasis on its conceptual aspects covering the history of the underlying ideas, major problems existing at present, and possible directions and approaches for future climate models. Since its introduction in the early 1960s, there have been decades of controversies in posing the cumulus parameterization problem. In this paper, it is suggested that confusion between budget and advection considerations is primarily responsible for the controversies. It is also pointed out that the performance of parameterization schemes can be better understood if one is not bound by their authors' justifications. The current trend in posing cumulus parameterization is away from deterministic diagnostic closures, including instantaneous adjustments, toward prognostic or nondeterministic closures, including relaxed and/or triggered adjustments. A number of questions need to be answered, however, for the merit of this trend to be fully utilized. Major practical and conceptual problems in the conventional approach of cumulus parameterization, which include artificial separations of processes and scales, are then discussed. It is rather obvious that for future climate models the scope of the problem must be drastically expanded from ""cumulus parameterization"" to ""unified cloud parameterization,"" or even to ""unified model physics."" This is an extremely challenging task, both intellectually and computationally, and the use of multiple approaches is crucial even for a moderate success. ""Cloud-resolving convective parameterization"" or ""superparameterization"" is a promising new approach that can develop into a multiscale modeling framework (MMF). It is emphasized that the use of such a framework can unify our currently diversified modeling efforts and make verification of climate models against observations much more constructive than it is now. Copyright © 2004 American Meteorological Society."
"25649793900;6602378790;57217561201;7003686398;6701497749;6602572031;7202180152;20434404100;8673075300;6603262263;7005751636;55462312300;6701585202;23018141700;","Incremental testing of the Community Multiscale Air Quality (CMAQ) modeling system version 4.7",2010,"10.5194/gmd-3-205-2010","https://www.scopus.com/inward/record.uri?eid=2-s2.0-78449236306&doi=10.5194%2fgmd-3-205-2010&partnerID=40&md5=80eac1678caab39669cfca12c535fc1d","This paper describes the scientific and structural updates to the latest release of the Community Multiscale Air Quality (CMAQ) modeling system version 4.7 (v4.7) and points the reader to additional resources for further details. The model updates were evaluated relative to observations and results from previous model versions in a series of simulations conducted to incrementally assess the effect of each change. The focus of this paper is on five major scientific upgrades: (a) updates to the heterogeneous N2O5 parameterization, (b) improvement in the treatment of secondary organic aerosol (SOA), (c) inclusion of dynamic mass transfer for coarse-mode aerosol, (d) revisions to the cloud model, and (e) new options for the calculation of photolysis rates. Incremental test simulations over the eastern United States during January and August 2006 are evaluated to assess the model response to each scientific improvement, providing explanations of differences in results between v4.7 and previously released CMAQ model versions. Particulate sulfate predictions are improved across all monitoring networks during both seasons due to cloud module updates. Numerous updates to the SOA module improve the simulation of seasonal variability and decrease the bias in organic carbon predictions at urban sites in the winter. Bias in the total mass of fine particulate matter (PM2.5) is dominated by overpredictions of unspeciated PM2.5 (PMother) in the winter and by underpredictions of carbon in the summer. The CMAQv4.7 model results show slightly worse performance for ozone predictions. However, changes to the meteorological inputs are found to have a much greater impact on ozone predictions compared to changes to the CMAQ modules described here. Model updates had little effect on existing biases in wet deposition predictions. © 2012 Author(s)."
"7410255460;7006432091;6701670597;","Multiscale variability of deep convection in relation to large-scale circulation in TOGA COARE",1996,"10.1175/1520-0469(1996)053<1380:MVODCI>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029769393&doi=10.1175%2f1520-0469%281996%29053%3c1380%3aMVODCI%3e2.0.CO%3b2&partnerID=40&md5=c53dd2132379c20e90adc0545b6aa83a","Deep convection over the Indo-Pacific oceanic warm pool in the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) occurred in cloud clusters, which grouped together in regions favoring their occurrence. These large groups of cloud clusters produced large-scale regions of satellite-observed cold cloud-top temperature. This paper investigates the manner in which the cloud clusters were organized on time and space scales ranging from the seasonal mean pattern over the whole warm-pool region to the scale of individual cloud clusters and their relationship to the large-scale circulation and sea surface temperature (SST). The dominant convective variability was associated with the intraseasonal oscillation (ISO). A large eastward propagating ensemble of cloud clusters marked the ISO's progress. The meridional structure of the ISO was strongly affected by the seasonal cycle with a southward shift from the Northern Hemisphere in October-November to the Southern Hemisphere in January-February. The SST had an intraseasonal signal in lagged quadrature with the cold cloudiness and rainfall in COARE. The SST increased (decreased) during the convectively suppressed (active) phases of the ISO. Enhanced low-level westerly winds occurred toward the later stages of the enhanced-convection periods of the ISO, though not always centered at the equator. The strongest westerlies tended to be located between two synoptic-scale cyclonic gyres, which were often not symmetric about the equator in the low-level wind field. This asymmetry in the anomalous equatorial low-level westerlies may have different implications for the oceanic response in the coupled atmosphere-ocean system than those centered on the equator. The cyclonic gyres contained highly concentrated deep convection, and, in four cases, the gyres developed into tropical cyclones. Within the envelope marking the convectively active phase of the ISO, cloud clusters were frequently concentrated into westward-propagating disturbances with a local periodicity of ∼2 days. These 2-day disturbances have been identified in earlier spectral studies and appear to be related to westward propagating inertio-gravity waves. In COARE, they typically contained numerous cloud clusters, which underwent a distinct diurnal cycle. Most of the cloud clusters embedded in the 2-day disturbances moved westward, though some were stationary, and a few moved eastward. A cloud-cluster tracking program identified groups of clusters (time clusters) that exhibited continuity in time and space. In the most convectively active period of the ISO, the tracking program identified almost the entire ISO cloud ensemble as a long-lasting, trackable superconvective system. This observation indicates the lack of a distinct scale-separation between convection and large-scale disturbances during the most intense convective periods in COARE."
"13402835300;7201485519;35509639400;6603925960;7004714030;7402064802;52464731300;7101959253;16679271700;57205867148;7102963655;","COSP: Satellite simulation software for model assessment",2011,"10.1175/2011BAMS2856.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79953115248&doi=10.1175%2f2011BAMS2856.1&partnerID=40&md5=b8beadabfa524b6ae8a0f63aab9ae94e","The Cloud Feedback Model Intercomparison Project (CFMIP) community has developed an integrated satellite simulator, the CFMIP Observation Simulator Package (COSP). COSP is a flexible software tool that enables the simulation from model variables of data from several satellite-borne active and passive sensors. COSP facilitates the evaluation of models against observations and comparisons between them in a more consistent manner. Two of the models used in this study are GCMs used in the latest IPCC assessment reports, and the others are two versions of the multiscale modeling framework (MMF) with different horizontal and vertical resolutions of the embedded cloud-resolving model. It is found that the MMF simulations perform better than the other climate models in all the diagnostics, showing a distribution of hydrometeors in the vertical and also in optical depth closer to the observations."
"7004091561;7003686398;14322460000;7004023573;20434404100;7005690017;6602931427;7801541902;","Model representation of secondary organic aerosol in CMAQv4.7",2010,"10.1021/es100636q","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77949345510&doi=10.1021%2fes100636q&partnerID=40&md5=f5269948a58701b81d3e941d9d85f0e7","Numerous scientific upgrades to the representation of secondary organic aerosol (SOA) are incorporated into the Community Multiscale Air Quality (CMAQ) modeling system. Additions include several recently identified SOA precursors: benzene, isoprene, and sesquiterpenes; and pathways: in-cloud oxidation of glyoxal and methylglyoxal, particle-phase oligomerization, and acid enhancement of isoprene SOA. NOx-dependent aromatic SOA yields are also added along with new empirical measurements of the enthalpies of vaporization and organic mass-to-carbon ratios. For the first time, these SOA precursors, pathways and empirical parameters are included simultaneously in an air quality model for an annual simulation spanning the continental U.S. Comparisons of CMAQ-modeled secondary organic carbon (OCsec) with semiempirical estimates screened from 165 routine monitoring sites across the U.S. indicate the new SOA module substantially improves model performance. The most notable improvement occurs in the central and southeastern U.S. where the regionally averaged temporal correlations (r) between modeled and semiempirical OC sec increase from -0.5 to 0.8 and -0.3 to 0.8, respectively, when the new SOA module is employed. Wintertime OCsec results improve in all regions of the continental U.S. and the seasonal and regional patterns of biogenic SOA are better represented. © 2010 American Chemical Society."
"7410221267;57034458200;7006864972;","A multiscale numerical study of Hurricane Andrew (1992). Part I: Explicit simulation and verification",1997,"10.1175/1520-0493(1997)125<3073:AMNSOH>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0001166264&doi=10.1175%2f1520-0493%281997%29125%3c3073%3aAMNSOH%3e2.0.CO%3b2&partnerID=40&md5=887eac1eeb5eef060daf5009a45bbe6a","In this study, the inner-core structures of Hurricane Andrew (1992) are explicitly simulated using an improved version of the Penn State-NCAR nonhydrostatic, two-way interactive, movable, triply nested grid mesoscale model (MM5). A modified Betts-Miller cumulus parameterization scheme and an explicit microphysics scheme were used simultaneously to simulate the evolution of the larger-scale flows over the coarser-mesh domains. The intense storm itself is explicitly resolved over the finest-mesh domain using a grid size 6 km and an explicit microphysics package containing prognostic equations for cloud water, ice rainwater, snow, and graupel. The model is initialized with the National Centers for Environmental Prediction analysis enhanced by a modified moisture field. A model-generated tropical-storm-like vortex was also incorporated. A 72-h integration was made, which covers the stages from the storm's initial deepening to a near-category 5 hurricane intensity and the landfall over Florida. As verified against various observations and the best analysis, the model captures reasonably well the evolution and inner-core structures of the storm. In particular, the model reproduces the track, the explosive deepening rate (&gt;1.5 hPa h-1), the minimum surface pressure of 919 hPa preceding landfall, the strong surface wind (&gt;65 m s-1) near the shoreline, as well as the ring of maximum winds, the eye, the eyewall, the spiral rainbands, and other cloud features. Of particular significance is that many simulated kinematics, thermodynamics, and precipitation stuctures in the core regions compare favorably to previous observations of hurricanes. The results suggest that it may be possible to predict reasonably the track, intensity, and inner-core structures of hurricans from the tropical synoptic conditions if high grid resolution, realistic model physics, and proper initial vortices (depth, size, and intensity) in relation to their larger-scale conditions (e.g., SST, moisture content, and vertical shear in the lower troposphere) are incorporated."
"6701335949;7004676489;26323138400;7005212820;55189671700;6602858513;","A multiscale nonhydrostatic atmospheric model using centroidal Voronoi tesselations and C-grid staggering",2012,"10.1175/MWR-D-11-00215.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84861385507&doi=10.1175%2fMWR-D-11-00215.1&partnerID=40&md5=753e5b901a3c9df22ad2b79a68e03908","The formulation of a fully compressible nonhydrostatic atmospheric model called the Model for Prediction Across Scales-Atmosphere (MPAS-A) is described. The solver is discretized using centroidal Voronoi meshes and a C-grid staggering of the prognostic variables, and it incorporates a split-explicit time-integration technique used in many existing nonhydrostatic meso- and cloud-scale models. MPAS can be applied to the globe, over limitedareas of the globe, and on Cartesian planes. The Voronoi meshes are unstructured grids that permit variable horizontal resolution. These meshes allow for applications beyond uniform-resolution NWP and climate prediction, in particular allowing embedded high-resolution regions to be used for regional NWP and regional climate applications. The rationales for aspects of this formulation are discussed, and results fromtests for nonhydrostatic flows on Cartesian planes and for large-scale flow on the sphere are presented. The resultsindicate that the solver is as accurate as existing nonhydrostatic solvers for nonhydrostatic-scale flows, and has accuracy comparable to existing global models using icosahedral(hexagonal) meshes for large-scale flows in idealized tests. Preliminary full-physics forecast results indicate that the solver formulation is robust and that the variable-resolution-mesh solutions are well resolved and exhibit no obvious problems in the mesh-transition zones. © 2012 American Meteorological Society."
"6701670597;14920137300;7501720647;7005035762;","The mesoscale convection life cycle: Building block or prototype for large-scale tropical waves?",2006,"10.1016/j.dynatmoce.2006.03.003","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33749827492&doi=10.1016%2fj.dynatmoce.2006.03.003&partnerID=40&md5=fb4457299e1dadb22f0ddeadffc8737c","A cumulonimbus cloud may ascend and spawn its anvil cloud, precipitation, and downdrafts within an hour or so. This paper inquires why a similar progression of events (life cycle) is observed for tropical weather fluctuations with time scales of hours, days, and even weeks. Regressions using point data illustrate the characteristic unit of rain production: the mesoscale convective system (MCS), covering tens of kilometers and lasting several hours, with embedded convective rain cells. Meanwhile, averages over larger spatial areas indicate a self-similar progression from shallow to deep convection to stratiform anvils on many time scales. Synthetic data exercises indicate that simple superpositions of fixed-structure MCS life cycles (the Building Block hypothesis) cannot explain why longer period life cycles are similar. Rather, it appears that an MCS may be a small analogue or prototype of larger scale waves. Multiscale structure is hypothesized to occur via a Stretched Building Block conceptual model, in which the widths (durations) of zones of shallow, deep, and stratiform anvil clouds in MCSs are modulated by larger scale waves. Temperature (T) and humidity (q) data are examined and fed into an entraining plume model, in an attempt to elucidate their relative roles in these large-scale convection zone variations. T profile variations, with wavelengths shorter than troposphere depth, appear important for high-frequency (∼ 2-5-day period) convectively coupled waves, as density directly links convection (via buoyancy) and large-scale wave dynamics (via restoring force). Still, the associated q anomalies are several times greater than adiabatic, suggesting a strong amplification by shallow convective feedbacks. For lower frequency (intraseasonal) variability, q anomalies are considerably larger compared to T, and may be dominant. © 2006 Elsevier B.V. All rights reserved."
"35563011600;","Star formation from galaxies to globules",2002,"10.1086/342177","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0043233523&doi=10.1086%2f342177&partnerID=40&md5=67a29d933597d39c3374cab124287d23","The origin of the empirical laws of galactic scale star formation is considered in view of the self-similar nature of interstellar gas and the observation that most local clusters are triggered by specific high-pressure events. The empirical laws suggest that galactic scale gravity is involved in the first stages of star formation, but they do not identify the actual triggering mechanisms for clusters in the final stages. Many triggering processes satisfy the empirical laws, including turbulence compression and expanding shell collapse. The self-similar nature of the gas and associated young stars suggests that turbulence is more directly involved, but the energy source for this turbulence is not clear, and the small-scale morphology of gas around most embedded clusters does not look like a random turbulent flow. Most clusters appear to be triggered by other nearby stars. Such a prominent local influence makes it difficult to understand the universality of the Kennicutt and Schmidt laws on galactic scales. A unified view of multiscale star formation avoids most of these problems. The Toomre and Kennicutt surface density thresholds, along with the large-scale gas and star formation morphology, imply that ambient self-gravity produces spiral arms and giant cloud complexes and at the same time drives much of the turbulence that leads to self-similar structures. Localized energy input from existing clusters and field supernovae drives turbulence and cloud formation too, while triggering clusters directly in preexisting clouds. The hierarchical structure in the gas made by turbulence ensures that the triggering time scales with size, thereby giving the Schmidt law over a wide range of scales and the size-duration correlation for young star fields. Reanalysis of the Schmidt law from a local point of view suggests that the efficiency of star formation is determined by the fraction of the gas above a critical density of around 105 m(H2) cm-3. Such high densities probably result from turbulence compression in a self-gravitating gas, in which case their mass fraction can be estimated from the density distribution function that results from turbulence. For Wada &amp; Norman's lognormal function that arises in whole-galaxy simulations, the theoretically predicted mass fraction of star-forming material is the same as that observed directly from the galactic Schmidt law and is ∼10-4. The unified view explains how independent star formation processes can combine into the empirical laws while preserving the fractal nature of interstellar gas and the pressurized, wind-swept appearance of most small-scale clouds. Likely variations in the relative roles of these processes from region to region should not affect the large-scale average star formation rate. Self-regulation by spiral instabilities and star formation ensures that most regions are in a marginally stable state in which turbulence limits the mass available for star formation and the overall rate is independent of the nature of the energy sources. In this sense, star formation is saturated to its largest possible value given the fractal nature of the interstellar medium."
"14043397000;36520959600;","A multiscale curvature algorithm for classifying discrete return LiDAR in forested environments",2007,"10.1109/TGRS.2006.890412","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33947708384&doi=10.1109%2fTGRS.2006.890412&partnerID=40&md5=4d8d3ee9665f787ce3b455f17b79df13","One prerequisite to the use of light detection and ranging (LiDAR) across disciplines is differentiating ground from nonground returns. The objective was to automatically and objectively classify points within unclassified LiDAR point clouds, with few model parameters and minimal postprocessing. Presented is an automated method for classifying LiDAR returns as ground or nonground in forested environments occurring in complex terrains. Multiscale curvature classification (MCC) is an iterative multiscale algorithm for classifying LiDAR returns that exceed positive surface curvature thresholds, resulting in all the LiDAR measurements being classified as ground or nonground. The MCC algorithm yields a solution of classified returns that support bare-earth surface interpolation at a resolution commensurate with the sampling frequency of the LiDAR survey. Errors in classified ground returns were assessed using 204 independent validation points consisting of 165 field plot global positioning system locations and 39 National Oceanic and Atmospheric Administration-National Geodetic Survey monuments. Jackknife validation and Monte Carlo simulation were used to assess the quality and error of a bare-earth digital elevation model interpolated from the classified returns. A local indicator of spatial association statistic was used to test for commission errors in the classified ground returns. Results demonstrate that the MCC model minimizes commission errors while retaining a high proportion of ground returns and provides high confidence in the derived ground surface."
"6603262527;24166936800;35831954800;35268384500;","Structural analysis of molecular clouds: Dendrograms",2008,"10.1086/587685","https://www.scopus.com/inward/record.uri?eid=2-s2.0-46349111235&doi=10.1086%2f587685&partnerID=40&md5=e252ecc8a9c8288f233e95b1f4321a4c","We demonstrate the utility of dendrograms at representing the essential features of the hierarchical structure of the isosurfaces for molecular line data cubes. The dendrogram of a data cube is an abstraction of the changing topology of the isosurfaces as a function of contour level. The ability to track hierarchical structure over a range of scales makes this analysis philosophically different from local segmentation algorithms like CLUMPFIND. Points in the dendrogram structure correspond to specific volumes in data cubes defined by their bounding isosurfaces. We further refine the technique by measuring the properties associated with each isosurface in the analysis allowing for a multiscale calculation of molecular gas properties. Using COMPLETE 13CO (J = 1 → 0) data from the L1448 region in Perseus and mock observations of a simulated data cube, we identify regions that have a significant contribution by self-gravity to their energetics on a range of scales. We find evidence for self-gravitation on all spatial scales in L1448, although not in all regions. In the simulated observations, nearly all of the emission is found in objects that would be self-gravitating if gravity were included in the simulation. We reconstruct the size-line-width relationship within the data cube using the dendrogram-derived properties and find it follows the standard relation: σv ∝ R0.58. Finally, we show that constructing the dendrogram of CO (J = 1 → 0) emission from the Orion-Monoceros region allows for the identification of giant molecular clouds in a blended molecular line data set using only a physically motivated definition (self-gravitating clouds with masses &gt;5 × 104 M⊙). © 2008. The American Astronomical Society. All rights reserved."
"6603363780;8841850200;55067687500;","Modeling river bed morphology, roughness, and surface sedimentology using high resolution terrestrial laser scanning",2012,"10.1029/2012WR012223","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84869996255&doi=10.1029%2f2012WR012223&partnerID=40&md5=8366adcea732e68c76e80daa7be8280a","Recent advances in technology have revolutionized the acquisition of topographic data, offering new perspectives on the structure and morphology of the Earth's surface. These developments have had a profound impact on the practice of river science, creating a step change in the dimensionality, resolution, and precision of fluvial terrain models. The emergence of ""hyperscale"" survey methods, including structure from motion photogrammetry and terrestrial laser scanning (TLS), now presents the opportunity to acquire 3-D point cloud data that capture grain-scale detail over reach-scale extents. Translating these data into geomorphologically relevant products is, however, not straightforward. Unlike traditional survey methods, TLS acquires observations rapidly and automatically, but unselectively. This results in considerable ""noise"" associated with backscatter from vegetation and other artifacts. Moreover, the large data volumes are difficult to visualize; require very high capacity storage; and are not incorporated readily into GIS and simulation models. In this paper we analyze the geomorphological integrity of multiscale terrain models rendered from a TLS survey of the braided River Feshie, Scotland. These raster terrain models are generated using a new, computationally efficient geospatial toolkit: the topographic point cloud analysis toolkit (ToPCAT). This performs an intelligent decimation of point cloud data into a set of 2.5-D terrain models that retain information on the high-frequency subgrid topography, as the moments of the locally detrended elevation distribution. The results quantify the degree of terrain generalization inherent in conventional fluvial DEMs and illustrate how subgrid topographic statistics can be used to map the spatial pattern of particle size, grain roughness, and sedimentary facies at the reach scale. © 2012 American Geophysical Union."
"7102745183;7006616050;","Dynamic modeling of orographically induced precipitation",1994,"10.1029/94RG00625","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0028572997&doi=10.1029%2f94RG00625&partnerID=40&md5=4ed6b517a6a702f23d87a99ee3b7004b","Local orography governs the triggering of cloud formation and the enhancement of processes such as condensation and hydrometeor nucleation and growth in mountainous regions. Intense, lengthy precipitation events are typical upwind of the topographic divide, with sharply decreasing magnitude and duration on the lee side. Differences in mean annual precipitation of several hundred percent between windward slopes of orographic barriers and adjacent valleys or lee side slopes are not unusual. Because much of the streamflow in areas such as the western United States is derived from mountainous areas that are remote and often poorly instrumented, modeling of orographic precipitation has important implications for water resources management. Models of orographically induced precipitation differ by their treatment of atmospheric dynamics and by the extent to which they rely on bulk parameterization of cloud and precipitation physics. Adiabatic ascent and a direct proportionality between precipitation efficiency and orographically magnified updrafts are the most frequent assumptions in orographic precipitation modeling. Space‐time discretization (i.e., resolution) is a major issue because of the high spatial variability of orographic precipitation. For a specific storm, relative errors as large as 50 to 100% are common in the forecast/hindcast of precipitation intensity and can be even larger in the case of catastrophic storms. When monthly or seasonal timescales are used to evaluate model performance, the magnitude of such errors decreases dramatically, reaching values as low as 10 to 15%. Current research is focusing on the development of data assimilation techniques to incorporate radar and satellite observations, and on the development of aggregation and disaggregation methodologies to address the implications of modeling a multiscale problem at restricted spatial and temporal resolutions. Copyright 1994 by the American Geophysical Union."
"56769708700;35099690000;8557497200;","FAST SEMANTIC SEGMENTATION of 3D POINT CLOUDS with STRONGLY VARYING DENSITY",2016,"10.5194/isprs-annals-III-3-177-2016","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85046284404&doi=10.5194%2fisprs-annals-III-3-177-2016&partnerID=40&md5=5556f4f85ed8a006ba1d16f1f19874ab","We describe an effective and efficient method for point-wise semantic classification of 3D point clouds. The method can handle unstructured and inhomogeneous point clouds such as those derived from static terrestrial LiDAR or photogammetric reconstruction; and it is computationally efficient, making it possible to process point clouds with many millions of points in a matter of minutes. The key issue, both to cope with strong variations in point density and to bring down computation time, turns out to be careful handling of neighborhood relations. By choosing appropriate definitions of a point's (multi-scale) neighborhood, we obtain a feature set that is both expressive and fast to compute. We evaluate our classification method both on benchmark data from a mobile mapping platform and on a variety of large, terrestrial laser scans with greatly varying point density. The proposed feature set outperforms the state of the art with respect to per-point classification accuracy, while at the same time being much faster to compute."
"55665687100;57166413400;","Atmospheric mercury simulation using the CMAQ model: Formulation description and analysis of wet deposition results",2002,"10.1016/S1352-2310(02)00220-0","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036280111&doi=10.1016%2fS1352-2310%2802%2900220-0&partnerID=40&md5=eb493fab6ed9c1e95cb60d98748283b4","The community multiscale air quality (CMAQ) modeling system has been adapted to simulate the emission, transport, transformation and deposition of atmospheric mercury (Hg) in three distinct forms: elemental Hg gas, reactive gaseous Hg, and particulate Hg. Emissions of Hg are currently defined from information published in the Environmental Protection Agency's Mercury Study Report to Congress. The atmospheric transport of these three forms of Hg is simulated in the same manner as for all other substances simulated by the CMAQ model to date. Transformations of Hg are simulated with four new chemical reactions within the standard CMAQ gaseous chemistry framework and a highly modified cloud chemistry mechanism which includes a compound-specific speciation for oxidized forms of Hg, seven new aqueous-phase Hg reactions, six aqueous Hg chemical equilibria, and a two-way mechanism for the sorption of dissolved oxidized Hg to elemental carbon particles. The CMAQ Hg model simulates the partitioning of reactive gaseous Hg between air and cloud water based on the Henry's constant for mercuric chloride. Henry's equilibrium is assumed for elemental Hg also. Particulate Hg is assumed to be incorporated into the aqueous medium during cloud nucleation. Wet and dry deposition is simulated for each of the three forms of Hg. Wet deposition rate is calculated based on precipitation information from the CMAQ meteorological processor and the physicochemical Hg speciation in the cloud chemistry mechanism. Dry deposition rate is calculated based on dry deposition velocity and air concentration information for each of the three forms of Hg. The horizontal modeling domain covers the central and eastern United States and adjacent southern Canada. An analysis of simulated Hg wet deposition versus weekly observations is performed. The results are described for two evaluation periods: 4 April-2 May 1995, and 20 June-18 July 1995."
"23009601400;57203235663;","Evaluation of the hydrological cycle over the Mississippi River Basin a simulated by the Canadian regional climate model (CRCM)",2007,"10.1175/JHM627.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-36348961925&doi=10.1175%2fJHM627.1&partnerID=40&md5=d942db8fc0b33ac90c0dce1008cf54ec","The water cycle over a given region is governed by many complex multiscale interactions and feedbacks, and their representation in climate models can vary in complexity. To understand which of the key processes require better representation, evaluation and validation of all components of the simulated water cycle are required. Adequate assessing of the simulated hydrological cycle over a given region is not trivial because observations for various water cycle components are seldom available at the regional scale. In this paper, a comprehensive validation method of the water budget components over a river basin is presented. In addition, the sensitivity of the hydrological cycle in the Canadian Regional Climate Model (CRCM) to a more realistic representation of the land surface processes, as well as radiation, cloud cover, and atmospheric boundary layer mixing is investigated. The changes to the physical parameterizations are assessed by evaluating the CRCM hydrological cycle over the Mississippi River basin. The first part of the evaluation looks at the basin annual means. The second part consists of the analysis and validation of the annual cycle of all water budget components. Finally, the third part is directed toward the spatial distribution of the annual mean precipitation, evapotranspiration, and runoff. Results indicate a strong response of the CRCM evapotranspiration and precipitation biases to the physical parameterization changes. Noticeable improvement was obtained in the simulated annual cycles of precipitation, evapotranspiration, moisture flux convergence, and terrestrial water storage tendency when more sophisticated physical parameterizations were used. Some improvements are also observed for the simulated spatial distribution of precipitation and evapotranspiration. The simulated runoff is less sensitive to changes in the CRCM physical parameterizations. © 2007 American Meteorological Society."
"36643323800;7202343918;6603109490;7102598804;7403483250;57211327514;7103209356;7403215206;6506717822;57206993458;7101844961;","A dynamically adapting weather and dispersion model: The operational multiscale environment model with grid adaptivity (OMEGA)",2000,"10.1175/1520-0493(2000)128<2044:ADAWAD>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033825648&doi=10.1175%2f1520-0493%282000%29128%3c2044%3aADAWAD%3e2.0.CO%3b2&partnerID=40&md5=d8db739c4ba47427b5471045578b2676","The Operational Multiscale Environment Model with Grid Adaptivtiy (OMEGA) and its embedded Atmospheric Dispersion Model is a new atmospheric simulation system for real-time hazard prediction, conceived out of a need to advance the state of the art in numerical weather prediction in order to improve the capability to predict the transport and diffusion of hazardous releases. OMEGA is based upon an unstructured grid that makes possible a continuosly varying horizontal grid resolution ranging from 100 km down to 1 km and a vertical resolution from a few tens of meters in the boundary layer to 1 km in the free atmosphere. OMEGA it also naturally scale spanning because its unstructured grid permits the addition of grid elements at any point in space and time. In particular, unstructured grid cells in the horizontal dimension can increase local resolution to better capture topography or the important physical features of the atmospheric circulation and cloud dynamics. This means that OMEGA can readily adapt its grid to stationary surface or terrain features, or to dynamic features in the evolving weather pattern. While adaptive numerical techniques have yet to be extensively applied in atmospheric models, the OMEGA model is the first model to exploit the adaptive nature of an unstructured gridding technique for atmospheric simulation and hence real-time hazard prediction. The purpose of this paper is to provide a detailed description of the OMEGA model, the OMEGA system, and a detailed comparison of OMEGA forecast results with data."
"7102643810;7102965584;7005461477;6602192728;6701809488;7407016988;7103107223;8315270100;7402079126;","Mesoscale and radar observations of the Fort Collins flash flood of 28 July 1997",1999,"10.1175/1520-0477(1999)080<0191:MAROOT>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0000455551&doi=10.1175%2f1520-0477%281999%29080%3c0191%3aMAROOT%3e2.0.CO%3b2&partnerID=40&md5=e4d3110c4817925637860404f4f2e50f","On the evening of 28 July 1997 the city of Fort Collins, Colorado, experienced a devastating flash flood that caused five fatalities and over 200 million dollars in damage. Maximum accumulations of rainfall in the western part of the city exceeded 10 in. in a 6-h period. This study presents a multiscale meteorological overview of the event utilizing a wide variety of instrument platforms and data including rain gauge, CSU-CHILL multiparameter radar, Next Generation Radar, National Lightning Detection Network, surface and Aircraft Communication Addressing and Reporting System observations, satellite observations, and synoptic analyses. Many of the meteorological features associated with the Fort Collins flash flood typify those of similar events in the western United States. Prominent features in the Fort Collins case included the presence of a 500-hPa ridge axis over northeastern Colorado; a weak shortwave trough on the western side of the ridge; postfrontal easterly upslope flow at low levels; weak to moderate southwesterly flow aloft; a deep, moist warm layer in the sounding; and the occurrence of a quasi-stationary rainfall system. In contrast to previous events such as the Rapid City or Big Thompson floods, the thermodynamic environment of the Fort Collins storm exhibited only modest instability, consistent with low lightning flash rates and an absence of hail and other severe storm signatures. Radar, rain gauge, and lightning observations provided a detailed view of the cloud and precipitation morphology. Polarimetric radar observations suggest that a coupling between warm-rain collision coalescence processes and ice processes played an important role in the rainfall production. Dual-Doppler radar and mesoscale wind analyses revealed that the low-level flow field associated with a bow echo located 60 km to the southeast of Fort Collins may have been responsible for a brief easterly acceleration in the low-level winds during the last 1.5 h of the event. The enhanced flow interacted with both topography and the convection located over Fort Collins, resulting in a quasi-stationary convective system and the heaviest rainfall of the evening."
"6507033203;14048222100;35232671500;","Multiscale geostatistical analysis of AVHRR, SPOT-VGT, and MODIS global NDVI products",2008,"10.1016/j.rse.2007.05.008","https://www.scopus.com/inward/record.uri?eid=2-s2.0-38049054713&doi=10.1016%2fj.rse.2007.05.008&partnerID=40&md5=99e1a2363e72b48e0013bc8505a440ea","Global NDVI data are routinely derived from the AVHRR, SPOT-VGT, and MODIS/Terra earth observation records for a range of applications from terrestrial vegetation monitoring to climate change modeling. This has led to a substantial interest in the harmonization of multisensor records. Most evaluations of the internal consistency and continuity of global multisensor NDVI products have focused on time-series harmonization in the spectral domain, often neglecting the spatial domain. We fill this void by applying variogram modeling (a) to evaluate the differences in spatial variability between 8-km AVHRR, 1-km SPOT-VGT, and 1-km, 500-m, and 250-m MODIS NDVI products over eight EOS (Earth Observing System) validation sites, and (b) to characterize the decay of spatial variability as a function of pixel size (i.e. data regularization) for spatially aggregated Landsat ETM+ NDVI products and a real multisensor dataset. First, we demonstrate that the conjunctive analysis of two variogram properties - the sill and the mean length scale metric - provides a robust assessment of the differences in spatial variability between multiscale NDVI products that are due to spatial (nominal pixel size, point spread function, and view angle) and non-spatial (sensor calibration, cloud clearing, atmospheric corrections, and length of multi-day compositing period) factors. Next, we show that as the nominal pixel size increases, the decay of spatial information content follows a logarithmic relationship with stronger fit value for the spatially aggregated NDVI products (R2 = 0.9321) than for the native-resolution AVHRR, SPOT-VGT, and MODIS NDVI products (R2 = 0.5064). This relationship serves as a reference for evaluation of the differences in spatial variability and length scales in multiscale datasets at native or aggregated spatial resolutions. The outcomes of this study suggest that multisensor NDVI records cannot be integrated into a long-term data record without proper consideration of all factors affecting their spatial consistency. Hence, we propose an approach for selecting the spatial resolution, at which differences in spatial variability between NDVI products from multiple sensors are minimized. This approach provides practical guidance for the harmonization of long-term multisensor datasets. © 2007 Elsevier Inc. All rights reserved."
"36237911700;7007116017;7005753053;6602093215;6603810234;56216723900;35248640700;6701665578;57203029706;35430328000;35461328600;6602312406;7005101262;","The ATLASGAL survey: A catalog of dust condensations in the Galactic plane",2014,"10.1051/0004-6361/201322434","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84899540123&doi=10.1051%2f0004-6361%2f201322434&partnerID=40&md5=1d7194783d833cb38a8e37bee345b7e6","Context. The formation processes and the evolutionary stages of high-mass stars are poorly understood compared to low-mass stars. Large-scale surveys are needed to provide an unbiased census of high column density sites that can potentially host precursors to high-mass stars. Aims. The ATLASGAL survey covers 420 sq.≠degree of the Galactic plane, between-80° &lt; â"""" &lt; +60° at 870 μm. Here we identify the population of embedded sources throughout the inner Galaxy. With this catalog we first investigate the general statistical properties of dust condensations in terms of their observed parameters, such as flux density and angular size. Then using mid-infrared surveys we aim to investigate their star formation activity and the Galactic distribution of star-forming and quiescent clumps. Our ultimate goal is to determine the statistical properties of quiescent and star-forming clumps within the Galaxy and to constrain the star formation processes. Methods. We optimized the source extraction method, referred to as MRE-GCL, for the ATLASGAL maps in order to generate a catalog of compact sources. This technique is based on multiscale filtering to remove extended emission from clouds to better determine the parameters corresponding to the embedded compact sources. In a second step we extracted the sources by fitting 2D Gaussians with the Gaussclumps algorithm. Results. We have identified in total 10861 compact submillimeter sources with fluxes above 5σ. Completeness tests show that this catalog is 97% complete above 5σ and &gt;99% complete above 7σ. Correlating this sample of clumps with mid-infrared point source catalogs (MSX at 21.3 μm and WISE at 22 μm), we have determined a lower limit of 33% that is associated with embedded protostellar objects. We note that the proportion of clumps associated with mid-infrared sources increases with increasing flux density, achieving a rather constant fraction of ~75% of all clumps with fluxes over 5 Jy/beam being associated with star formation. Examining the source counts as a function of Galactic longitude, we are able to identify the most prominent star-forming regions in the Galaxy. Conclusions. We present here the compact source catalog of the full ATLASGAL survey and investigate their characteristic properties. From the fraction of the likely massive quiescent clumps (~25%), we estimate a formation time scale of ~ 7.5 ± 2.5 × 104 yr for the deeply embedded phase before the emergence of luminous young stellar objects. Such a short duration for the formation of high-mass stars in massive clumps clearly proves that the earliest phases have to be dynamic with supersonic motions. © 2014 ESO."
"56009810800;7004868129;7202447177;7003557662;","Boundary layer and shallow cumulus clouds in a medium-range forecast of a large-scale weather system",2005,"10.1175/MWR2958.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-24144449556&doi=10.1175%2fMWR2958.1&partnerID=40&md5=162630bac424713eb545bc66c5a71b2c","The role and impact that boundary layer and shallow cumulus clouds have on the medium-range forecast of a large-scale weather system is discussed in this study. A mesoscale version of the Global Environmental Multiscale (GEM) atmospheric model is used to produce a 5-day numerical forecast of a midlatitude large-scale weather system that occurred over the Pacific Ocean during February 2003. In this version of GEM, four different schemes are used to represent (i) boundary layer clouds (including stratus, stratocumulus, and small cumulus clouds), (ii) shallow cumulus clouds (overshooting cumulus), (iii) deep convection, and (iv) nonconvective clouds. Two of these schemes, that is, the so-called MoisTKE and Kuo Transient schemes for boundary layer and overshooting cumulus clouds, respectively, have been recently introduced in GEM and are described in more detail. The results show that GEM, wit h this new cloud package, is able to represent the wide variety of clouds observed in association with the large-scale weather system. In particular, it is found that the Kuo Transient scheme is mostly responsible for the shallow/intermediate cumulus clouds in the rear portion of the large-scale system, whereas MoisTKE produces the low-level stratocumulus clouds ahead of the system. Several diagnostics for the rear portion of the system reveal that the role of MoisTKE is mainly to increase the vertical transport (diffusion) associated with the boundary layer clouds, while Kuo Transient is acting in a manner more consistent with convective stabilization. As a consequence, MoisTKE is not able to remove the low-level shallow cloud layer that is incorrectly produced by the GEM nonconvective condensation scheme. Kuo Transient, in contrast, led to a significant reduction of these nonconvective clouds, in better agreement with satellite observations. This improved representation of stratocumulus and cumulus clouds does not have a large impact on the overall sea level pressure patterns of the large-scale weather system. Precipitation in the rear portion of the system, however, is found to be smoother when MoisTKE is used, and significantly less when the Kuo Transient scheme is switched on."
"7006429360;7005565819;7202613485;","Ensemble kalman filter assimilation of radar observations of the 8 may 2003 oklahoma city supercell: Influences of reflectivity observations on storm-scale analyses",2011,"10.1175/2010MWR3438.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79951643932&doi=10.1175%2f2010MWR3438.1&partnerID=40&md5=3c93060811e20f7f56e49b9877dd3e90","Ensemble Kalman filter (EnKF) techniques have been proposed for obtaining atmospheric state estimates on the scale of individual convective storms from radar and other observations, but tests of these methods with observations of real convective storms are still very limited. In the current study, radar observations of the 8 May 2003 Oklahoma City tornadic supercell thunderstorm were assimilated into the National Severe Storms Laboratory (NSSL) Collaborative Model for Multiscale Atmospheric Simulation (NCOMMAS) with an EnKF method. The cloud model employed 1-km horizontal grid spacing, a single-moment bulk precipitationmicrophysics scheme, and a base state initialized with sounding data. A 50-member ensemble was produced by randomly perturbing base-state wind profiles and by regularly adding random local perturbations to the horizontal wind, temperature, and water vapor fields in and near observed precipitation. In a reference experiment, only Doppler-velocity observations were assimilated into the NCOMMAS ensemble. Then, radar-reflectivity observations were assimilated together with Doppler-velocity observations in subsequent experiments. Influences that reflectivity observations have on storm-scale analyses were revealed through parameter-space experiments by varying observation availability, observation errors, ensemble spread, and choices for what model variables were updated when a reflectivity observation was assimilated. All experiments produced realistic storm-scale analyses that compared favorably with independent radar observations. Convective storms in the NCOMMAS ensemble developed more quickly when reflectivity observations and velocity observations were both assimilated rather than only velocity, presumably because the EnKF utilized covariances between reflectivity and unobserved model fields such as cloud water and vertical velocity in efficiently developing realistic storm features. Recurring spatial patterns in the differences between predicted and observed reflectivity were noted particularly at low levels, downshear of the supercell's updraft, in the anvil of moderate-to-light precipitation, where reflectivity in the model was typically lower than observed. Bias errors in the predicted rain mixing ratios and/or the size distributions that the bulk scheme associates with these mixing ratios are likely responsible for this reflectivity underprediction. When a reflectivity observation is assimilated, bias errors in the model fields associated with reflectivity (rain, snow, and hail-graupel) can be projected into other model variables through the ensemble covariances. In the current study, temperature analyses in the downshear anvil at low levels, where reflectivity was underpredicted, were very sensitive both to details of the assimilation algorithm and to ensemble spread in temperature. This strong sensitivity suggests low confidence in analyses of low-level cold pools obtained through reflectivity-data assimilation. © 2011 American Meteorological Society."
"6603156461;36867775200;6603268269;7006270084;","Simulating the evolution of soot mixing state with a particle-resolved aerosol model",2009,"10.1029/2008JD011073","https://www.scopus.com/inward/record.uri?eid=2-s2.0-68249099910&doi=10.1029%2f2008JD011073&partnerID=40&md5=c467cb6ac85d1f4ad2780f0064fefdef","[1] The mixing state of soot particles in the atmosphere is of crucial importance for assessing their climatic impact, since it governs their chemical reactivity, cloud condensation nuclei activity, and radiative properties. To improve the mixing state representation in models, we present a new approach, the stochastic particle-resolved model PartMC-MOSAIC, which explicitly resolves the composition of individual particles in a given population of different types of aerosol particles. This approach tracks the evolution of the mixing state of particles due to emission, dilution, condensation, and coagulation. To make this direct stochastic particle-based method practical, we implemented a new multiscale stochastic coagulation method. With this method we achieved high computational efficiency for situations when the coagulation kernel is highly nonuniform, as is the case for many realistic applications. PartMC-MOSAIC was applied to an idealized urban plume case representative of a large urban area to simulate the evolution of carbonaceous aerosols of different types due to coagulation and condensation. For this urban plume scenario we quantified the individual processes that contributed to the aging of the aerosol distribution, illustrating the capabilities of our modeling approach. The results showed for the first time the multidimensional structure of particle composition, which is usually lost in sectional or modal aerosol models. Copyright 2009 by the American Geophysical Union."
"6701346974;6507017020;7202208382;","Evaluation of the simulated interannual and subseasonal variability in an AMIP-style simulation using the CSU multiscale modeling framework",2008,"10.1175/2007JCLI1630.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-40849150834&doi=10.1175%2f2007JCLI1630.1&partnerID=40&md5=f74f495a653ba891c381755f0beee5bc","The Colorado State University (CSU) Multiscale Modeling Framework (MMF) is a new type of general circulation model (GCM) that replaces the conventional parameterizations of convection, clouds, and boundary layer with a cloud-resolving model (CRM) embedded into each grid column. The MMF has been used to perform a 19-yr-long Atmospheric Model Intercomparison Project-style simulation using the 1985-2004 sea surface temperature (SST) and sea ice distributions as prescribed boundary conditions. Particular focus has been given to the simulation of the interannual and subseasonal variability. The annual mean climatology is generally well simulated. Prominent biases include excessive precipitation associated with the Indian and Asian monsoon seasons, precipitation-deficits west of the Maritime Continent and over Amazonia, shortwave cloud effect biases west of the subtropical continents due to insufficient stratocumulus clouds, and longwave cloud effect biases due to overestimation of high cloud amounts, especially in the tropics. ne geographical pattern of the seasonal cycle of precipitation is well reproduced, although the seasonal variance is considerably overestimated mostly because of the excessive monsoon precipitation mentioned above. The MMF does a good job of reproducing the interannual variability in terms of the spatial structure and magnitude of major anomalies associated with El Niño-Southern Oscillation (ENSO). The subseasonal variability of tropical climate associated with the Madden-Julian oscillation (MJO) and equatorially trapped waves are particular strengths of the simulation. The wavenumber-frequency power spectra of the simulated outgoing longwave radiation (OLR), precipitation rate, and zonal wind at 200 and 850 mb for time scales in the range of 2-96 days compare very well to the spectra derived from observations, and show a robust MJO and Kelvin and Rossby waves with phase speeds similar to those observed. The geographical patterns of the MJO and Kelvin wave-filtered OLR variance for summer and winter seasons are well simulated; however, the variances tend to be overestimated by as much as 50%. The observed seasonal and interannual variations of the strength of the MJO are also well reproduced. The physical realism of the simulated marine stratocumulus clouds is demonstrated by an analysis of the composite diurnal cycle of cloud water content, longwave (IR) cooling, vertical velocity variance, rainfall, and subcloud vertical velocity skewness. The relationships between vertical velocity variance, IR cooling, and negative skewness all suggest that, despite the coarse numerical grid of the CRM, the simulated clouds behave in a manner consistent with the understanding of the stratocumulus dynamics. In the stratocumulus-to-cumulus transition zone, the diurnal cycle of the inversion layer as simulated by the MMF also bears a remarkable resemblance to in situ observations. It is demonstrated that in spite of the coarse spacing of the CRM grid used in the current version of MMF, the bulk of vertical transport of water in the MMF is carried out by the circulations explicitly represented on the CRM grid rather than by the CRM's subgrid-scale parameterization. © 2008 American Meteorological Society."
"35329368900;7003283811;8408994300;","Multiscale observations of hurricane dennis (2005): The effects of hot towers on rapid intensification",2010,"10.1175/2009JAS3119.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77953270767&doi=10.1175%2f2009JAS3119.1&partnerID=40&md5=19827d904401adff30445dc2b9de2bff","A synthesis of remote sensing and in situ observations throughout the life cycle of Hurricane Dennis (2005) during the NASA Tropical Cloud Systems and Processes (TCSP) experiment is presented. Measurements from the ER-2 Doppler radar (EDOP), the Advanced Microwave Sounding Unit (AMSU), airborne radiometer, and flight-level instruments are used to provide a multiscale examination of the storm. The main focus is an episode of deep convective bursts (""hot towers"") occurring during a mature stage of the storm and preceding a period of rapid intensification (11-hPa pressure drop in 1 h 35 min). The vigorous hot towers penetrated to 16-km height, had maximum updrafts of 20 m s-1 at 12-14-km height, and possessed a strong transverse circulation through the core of the convection. Significant downdrafts (maximum of 10-12 m s-1) on the flanks of the updrafts were observed, with their cumulative effects hypothesized to result in the observed increases in the warm core. In one ER-2 overpass, subsidence was transported toward the eye by 15-20 m s-1 inflow occurring over a deep layer (0.5-10 km) coincident with a hot tower. Fourier analysis of the AMSU satellite measurements revealed a large shift in the storm's warm core structure, from asymmetric to axisymmetric, ~12 h after the convective bursts began. In addition, flight-level wind calculations of the axisymmetric tangential velocity and inertial stability showed a contraction of the maximum winds and an increase in the stiffness of the vortex, respectively, after the EDOP observations. The multiscale observations presented here reveal unique, ultra-high-resolution details of hot towers and their coupling to the parent vortex, the balanced dynamics of which can be generally explained by the axisymmetrization and efficiency theories."
"7202619752;7003348606;7005120823;7003718864;6506113986;7102926738;6507418455;","The 1993 superstorm cold surge: Frontal structure, gap flow, and tropical impact",1997,"10.1175/1520-0493(1997)125<0005:TSCSFS>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0003116530&doi=10.1175%2f1520-0493%281997%29125%3c0005%3aTSCSFS%3e2.0.CO%3b2&partnerID=40&md5=bb211c137dbb636e2e7697e66c837774","In the wake of the eastern United States cyclone of 12-14 March 1993, a cold surge, originating over Alaska and western Canada, brought northerlies exceeding 20 m s-1 and temperature decreases up to 15°C over 24 h into Mexico and Central America. This paper addresses the multiscale aspects of the surge from the planetary scale to the mesoscale, focusing on 1) the structure and evolution of the leading edge of the cold surge, 2) the reasons for its extraordinary intensity and equatorward extent, and 3) the impact of the surge on the Tropics, specifically, on the strength of the trade winds and on the sea surface temperature in the eastern Pacific. The cold surge was initiated as a developing cyclone over the Gulf of Mexico, and an upstream anticyclone east of the Rockies caused an along-barrier pressure gradient to form, forcing topographically channeled northerlies along the Rocky and Sierra Madre Mountains to transport cold air equatorward. On the mesoscale, the leading edge of the cold surge possessed nonclassical frontal structure. For example, as the cold surge entered Mexico, the coldest air and the strongest wind arrived at about 900 hPa before affecting the surface, suggestive of a tipped-forward leading edge to the surge. Also, satellite imagery and surface observations indicate that the leading edge appeared to be successively regenerated in the warm presurge air. The cold surge had characteristics reminiscent of a Kelvin wave, a tipped-forward cold front, a pressure-jump line, a bore, and a gravity current, but none of these conceptual/dynamical models was fully applicable. Associated with the cold surge, gap winds up to 25 m s-1 were observed in the Gulfs of Tehuantepec (a tehuantepecer), Fonseca, Papagayo, and Panama, owing to the strong cross-mountain pressure gradient. In the case of the tehuantepecer, a rope cloud emanated from the Isthmus of Tehuantepec and turned anticyclonically, consistent with an inertial oscillation. On the synoptic and planetary scales, the extraordinary equatorward extent of the cold surge was aided by topographic channeling similar to cold-air damming, by a low-latitude upper-tropospheric trough, and by the lower branch of the secondary circulation associated with a confluent jet-entrance region aloft. The cold surge also impacted the tropical atmosphere and ocean, by contributing to the strengthening of the northeast trade winds over the eastern Pacific Ocean and by inducing local cooling of the sea surface temperature in the Gulfs of Tehuantepec and Papagayo by about 4°-8°C."
"7103126833;7102369927;36741042500;7201398636;7201437448;35425197200;","The experimental HWRF system: A study on the influence of horizontal resolution on the structure and intensity changes in tropical cyclones using an idealized framework",2011,"10.1175/2010MWR3535.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-78651083069&doi=10.1175%2f2010MWR3535.1&partnerID=40&md5=b187798c7da5eb533f6145d3a3f43bae","Forecasting intensity changes in tropical cyclones (TCs) is a complex and challenging multiscale problem. While cloud-resolving numerical models using a horizontal grid resolution of 1-3 km are starting to show some skill in predicting the intensity changes in individual cases, it is not clear at this time what may be a reasonable horizontal resolution for forecasting TC intensity changes on a day-to-day-basis. The Experimental Hurricane Weather Research and Forecasting System (HWRFX) was used within an idealized framework to gain a fundamental understanding of the influence of horizontal grid resolution on the dynamics of TC vortex intensification in three dimensions. HWFRX is a version of the National Centers for Environmental Prediction (NCEP) Hurricane Weather Research and Forecasting (HWRF) model specifically adopted and developed jointly at NOAA's Atlantic Oceanographic and Meteorological Laboratory (AOML) and Earth System Research Laboratory (ESRL) for studying the intensity change problem at a model grid resolution of about 3 km. Based on a series of numerical experiments at the current operating resolution of about 9 km and at a finer resolution of about 3 km, it was found that improved resolution had very little impact on the initial spinup of the vortex. An initial axisymmetric vortex with a maximum wind speed of 20 m s-1 rapidly intensified to 50 m s-1 within about 24 h in either case. During the spinup process, buoyancy appears to have had a pivotal influence on the formation of the warm core and the subsequent rapid intensification of the modeled vortex. The high-resolution simulation at 3 km produced updrafts as large as 48 m s-1. However, these extreme events were rare, and this study indicated that these events may not contribute significantly to rapid deepening. Additionally, although the structure of the buoyant plumes may differ at 9-and 3-km resolution, interestingly, the axisymmetric structure of the simulated TCs exhibited major similarities. Specifically, the similarities included a deep inflow layer extending up to about 2 km in height with a tangentially averaged maximum inflow velocity of about 12-15 m s-1, vertical updrafts with an average velocity of about 2 m s-1, and a very strong outflow produced at both resolutions for a mature storm. It was also found in either case that the spinup of the primary circulation occurred not only due to the weak inflow above the boundary layer but also due to the convergence of vorticity within the boundary layer. Nevertheless, the mature phase of the storm's evolution exhibited significantly different patterns of behavior at 9 and 3 km. While the minimum pressure at the end of 96 h was 934 hPa for the 9-km simulation, it was about 910 hPa for the 3-km run. The maximum tangential wind at that time showed a difference of about 10 m s-1. Several sensitivity experiments related to the initial vortex intensity, initial radius of the maximum wind, and physics were performed. Based on ensembles of simulations, it appears that radial advection of the tangential wind and, consequently, radial flux of vorticity become important forcing terms in the momentum budget of the mature storm. Stronger convergence in the boundary layer leads to a larger transport of moisture fluxes and, subsequently, a stronger storm at higher resolution. © 2011 American Meteorological Society."
"27171906700;36538539800;25937584800;55624488227;55501554900;7006461606;25121514600;35975306400;7202839433;","Understanding of regional air pollution over China using CMAQ, part II. Process analysis and sensitivity of ozone and particulate matter to precursor emissions",2010,"10.1016/j.atmosenv.2010.03.036","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77955512288&doi=10.1016%2fj.atmosenv.2010.03.036&partnerID=40&md5=c932b224dd718e057a4f8928b88849a0","Following model evaluation in part I, this part II paper focuses on the process analysis and chemical regime analysis for the formation of ozone (O3) and particulate matter with aerodynamic diameter less than or equal to 10 μm (PM10) in China. The process analysis results show that horizontal transport is the main contributor to the accumulation of O3 in Jan., Apr., and Oct., and gas-phase chemistry and vertical transport contribute to the production and accumulation of O3 in Jul. Removal pathways of O3 include vertical and horizontal transport, gas-phase chemistry, and cloud processes, depending on locations and seasons. PM10 is mainly produced by primary emissions and aerosol processes and removed by horizontal transport. Cloud processes could either decrease or increase PM10 concentrations, depending on locations and seasons. Among all indicators examined, the ratio of PHNO3/PH2O2 provides the most robust indicator for O3 chemistry, indicating a VOC-limited O3 chemistry over most of the eastern China in Jan., NOx-limited in Jul., and either VOC- or NOx-limited in Apr. and Oct. O3 chemistry is NOx-limited in most central and western China and VOC-limited in major cities throughout the year. The adjusted gas ratio, AdjGR, indicates that PM formation in the eastern China is most sensitive to the emissions of SO2 and may be more sensitive to emission reductions in NOx than in NH3. These results are fairly consistent with the responses of O3 and PM2.5 to the reductions of their precursor emissions predicted from sensitivity simulations. A 50% reduction of NOx or AVOC emissions leads to a reduction of O3 over the eastern China. Unlike the reduction of emissions of SO2, NOx, and NH3 that leads to a decrease in PM10, a 50% reduction of AVOC emissions increases PM10 levels. Such results indicate the complexity of O3 and PM chemistry and a need for an integrated, region-specific emission control strategy with seasonal variations to effectively control both O3 and PM2.5 pollution in China. © 2010 Elsevier Ltd."
"37011423400;36064917000;25926243500;7005906188;55500134600;7101947159;55577486600;56381700700;55724964400;","A multiscale and hierarchical feature extraction method for terrestrial laser scanning point cloud classification",2015,"10.1109/TGRS.2014.2359951","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84920999915&doi=10.1109%2fTGRS.2014.2359951&partnerID=40&md5=828929b320d96fb5be93afd734ddb08c","The effective extraction of shape features is an important requirement for the accurate and efficient classification of terrestrial laser scanning (TLS) point clouds. However, the challenge of how to obtain robust and discriminative features from noisy and varying density TLS point clouds remains. This paper introduces a novel multiscale and hierarchical framework, which describes the classification of TLS point clouds of cluttered urban scenes. In this framework, we propose multiscale and hierarchical point clusters (MHPCs). In MHPCs, point clouds are first resampled into different scales. Then, the resampled data set of each scale is aggregated into several hierarchical point clusters, where the point cloud of all scales in each level is termed a point-cluster set. This representation not only accounts for the multiscale properties of point clouds but also well captures their hierarchical structures. Based on the MHPCs, novel features of point clusters are constructed by employing the latent Dirichlet allocation (LDA). An LDA model is trained according to a training set. The LDA model then extracts a set of latent topics, i.e., a feature of topics, for a point cluster. Finally, to apply the introduced features for point-cluster classification, we train an AdaBoost classifier in each point-cluster set and obtain the corresponding classifiers to separate the TLS point clouds with varying point density and data missing into semantic regions. Compared with other methods, our features achieve the best classification results for buildings, trees, people, and cars from TLS point clouds, particularly for small and moving objects, such as people and cars. © 1980-2012 IEEE."
"8958042500;8316438800;35571980900;57203088154;","The CO-H2conversion factor in disc galaxies and mergers",2011,"10.1111/j.1365-2966.2011.19516.x","https://www.scopus.com/inward/record.uri?eid=2-s2.0-81055156688&doi=10.1111%2fj.1365-2966.2011.19516.x&partnerID=40&md5=b59cce37041af777659b8b5dcc29a105","Relating the observed CO emission from giant molecular clouds (GMCs) to the underlying H2 column density is a long-standing problem in astrophysics. While the Galactic CO-H2 conversion factor (XCO) appears to be reasonably constant, observations indicate thatXCO may be depressed in high surface density starburst environments. Using a multiscale approach, we investigate the dependence ofXCO on the galactic environment in numerical simulations of disc galaxies and galaxy mergers.XCO is proportional to the GMC surface density divided by the integrated CO intensity,WCO, andWCO is related to the kinetic temperature and velocity dispersion in the cloud. In disc galaxies (except within the central ∼kpc), the galactic environment is largely unimportant in setting the physical properties of GMCs provided they are gravitationally bound. The temperatures are roughly constant at ∼10K due to the balance of CO cooling and cosmic ray heating, giving a nearly constant CO-H2 conversion factor in discs. In mergers, the velocity dispersion of the gas rises dramatically during coalescence. The gas temperature also rises as it couples well to the warm (∼50K) dust at high densities (n&gt; 104cm-3). The rise in velocity dispersion and temperature combine to offset the rise in surface density in mergers, causingXCO to drop by a factor of ∼2-10 compared to the disc simulation. This model predicts that high-resolution Atacama Large Millimeter/submillimeter Array observations of nearby ultraluminous infrared galaxies should show velocity dispersions of 101-102kms-1, and brightness temperatures comparable to the dust temperatures. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS."
"12040239100;6602848822;","Improving spatial soil moisture representation through integration of AMSR-E and MODIS products",2012,"10.1109/TGRS.2011.2161318","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84856317691&doi=10.1109%2fTGRS.2011.2161318&partnerID=40&md5=1152d104615e7913d24741c4870f0200","The use of microwave observations has been highlighted as a complementary tool for evaluating land surface properties. Microwave observations are less affected by clouds, water vapor, and aerosol and also contain valuable soil moisture information. However, a critical limitation in microwave observations is the coarse spatial resolution attributed to the complex retrieval process. The objective of the current study is to develop an independent (from ground observations) downscaling approach that merges information from higher spatial resolution MODerate-resolution Imaging Spectroradiometer (MODIS) (∼1 km) with lower spatial resolution AMSR-E (∼25 km) to obtain soil moisture estimates at the MODIS scale (∼1 km). We compare the developed (UCLA) method against a range of previous published approaches. Various key factors (i.e., surface temperature, vegetation indexes, and albedo) derived from MODIS provide information on relative variations in surface wetness conditions and contribute weighting parameters for downscaling the larger AMSR-E soil moisture footprints. Evaluation of the various downscaled soil moisture products is undertaken at the SMEX04 site in southern Arizona. Results show that the UCLA downscaling technique, as well as the previously published Merlin method, significantly improves the limited spatial variability of the current AMSR-E product. Spatial correlation (R) values improved from -0.08 to 0.34 and 0.27 for the Merlin and UCLA methods, respectively. The evaluated triangle-based methods show poorer performance over the study domain. Results from the current study yield insight on the integration of multiscale remote sensing data in various downscaling methods and the usefulness of MODIS observations in compensating for low-resolution microwave observations. © 2006 IEEE."
"25031430500;7103158465;","Advanced two-moment bulk microphysics for global models. Part I: Off-line tests and comparison with other schemes",2015,"10.1175/JCLI-D-14-00102.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84923065772&doi=10.1175%2fJCLI-D-14-00102.1&partnerID=40&md5=15d7c8ed0066e0cc81395aabedb0883e","Prognostic precipitation is added to a cloud microphysical scheme for global climate models. Results indicate very similar performance to other commonly used mesoscale schemes in an offline driver for idealized warm rain cases, better than the previous version of the global model microphysics scheme with diagnostic precipitation. In the mixed phase regime, there is significantly more water and less ice, which may address a common bias seen with the scheme in climate simulations in the Arctic. For steady forcing cases, the scheme has limited sensitivity to time step out to the ~15-min time steps typical of global models. The scheme is similar to other schemes with moderate sensitivity to vertical resolution. The limited time step sensitivity bodes well for use of the scheme in multiscale models from the mesoscale to the large scale. The scheme is sensitive to idealized perturbations of cloud drop and crystal number. Precipitation decreases and condensate increases with increasing drop number, indicating substantial decreases in precipitation efficiency. The sensitivity is less than with the previous version of the scheme for low drop number concentrations (Nc &lt; 100 cm -3). Ice condensate increases with ice number, with large decreases in liquid condensate as well for a mixed phase case. As expected with prognostic precipitation, accretion is stronger than with diagnostic precipitation and the accretion to autoconversion ratio increases faster with liquid water path (LWP), in better agreement with idealized models and earlier studies than the previous version. © 2015 American Meteorological Society."
"8881295900;7003686398;6701585202;20434404100;6602378790;","Evaluation of the community multiscale air quality (CMAQ) model version 4.5: Sensitivities impacting model performance; Part II-particulate matter",2008,"10.1016/j.atmosenv.2008.03.036","https://www.scopus.com/inward/record.uri?eid=2-s2.0-47549117372&doi=10.1016%2fj.atmosenv.2008.03.036&partnerID=40&md5=7b8ca86e894ddc27d9f74000d7591022","This paper is Part II in a pair of papers that examines the results of the Community Multiscale Air Quality (CMAQ) model version 4.5 (v4.5) and discusses the potential explanations for the model performance characteristics seen. The focus of this paper is on fine particulate matter (PM2.5) and its chemical composition. Improvements made to the dry deposition velocity and cloud treatment in CMAQ v4.5 addressing compensating errors in 36-km simulations improved particulate sulfate (SO42-) predictions. Large overpredictions of particulate nitrate (NO3-) and ammonium (NH4+) in the fall are likely due to a gross overestimation of seasonal ammonia (NH3) emissions. Carbonaceous aerosol concentrations are substantially underpredicted during the late spring and summer months, most likely due, in part, to a lack of some secondary organic aerosol (SOA) formation pathways in the model. Comparisons of CMAQ PM2.5 predictions with observed PM2.5 mass show mixed seasonal performance. Spring and summer show the best overall performance, while performance in the winter and fall is relatively poor, with significant overpredictions of total PM2.5 mass in those seasons. The model biases in PM2.5 mass cannot be explained by summing the model biases for the major inorganic ions plus carbon. Errors in the prediction of other unspeciated PM2.5 (PMOther) are largely to blame for the errors in total PM2.5 mass predictions, and efforts are underway to identify the cause of these errors."
"7403921170;7006621313;57207592379;6602569468;","Multiscale statistical properties of a high-resolution precipitation forecast",2001,"10.1175/1525-7541(2001)002<0406:MSPOAH>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0035539586&doi=10.1175%2f1525-7541%282001%29002%3c0406%3aMSPOAH%3e2.0.CO%3b2&partnerID=40&md5=966db1ef8e7180aae50879fe95af13ed","Small-scale (less than ∼ 15 km) precipitation variability significantly affects the hydrologic response of a basin and the accurate estimation of water and energy fluxes through coupled land-atmosphere modeling schemes. It also affects the radiative transfer through precipitating clouds and thus rainfall estimation from microwave sensors. Because both land-atmosphere and cloud-radiation interactions are nonlinear and occur over a broad range of scales (from a few centimeters to several kilometers), it is important that, over these scales, cloud-resolving numerical models realistically reproduce the observed precipitation variability. This issue is examined herein by using a suite of multiscale statistical methods to compare the scale dependence of precipitation variability of a numerically simulated convective storm with that observed by radar. In particular, Fourier spectrum, structure function, and moment-scale analyses are used to show that, although the variability of modeled precipitation agrees with that observed for scales larger than approximately 5 times the model resolution, the model shows a falloff in variability at smaller scales. Thus, depending upon the smallest scale at which variability is considered to be important for a specific application, one has to resort either to very high resolution model runs (resolutions 5 times higher than the scale of interest) or to stochastic methods that can introduce the missing small-scale variability. The latter involve upscaling the model output to a scale approximately 5 times the model resolution and then stochastically downscaling it to smaller scales. The results of multiscale analyses, such as those presented herein, are key to the implementation of such stochastic downscaling methodologies."
"57203054708;36987319800;55713076400;","Toward unification of the multiscale modeling of the atmosphere",2011,"10.5194/acp-11-3731-2011","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79955375427&doi=10.5194%2facp-11-3731-2011&partnerID=40&md5=198aab7ba39ff73ca21984c49af176b7","As far as the representation of deep moist convection is concerned, only two kinds of model physics are used at present: highly parameterized as in the conventional general circulation models (GCMs) and explicitly simulated as in the cloud-resolving models (CRMs). Ideally, these two kinds of model physics should be unified so that a continuous transition of model physics from one kind to the other takes place as the resolution changes. With such unification, the GCM can converge to a global CRM (GCRM) as the grid size is refined. This paper suggests two possible routes to achieve the unification. ROUTE I continues to follow the parameterization approach, but uses a unified parameterization that is applicable to any horizontal resolutions between those typically used by GCMs and CRMs. It is shown that a key to construct such a unified parameterization is to eliminate the assumption of small fractional area covered by convective clouds, which is commonly used in the conventional cumulus parameterizations either explicitly or implicitly. A preliminary design of the unified parameterization is presented, which demonstrates that such an assumption can be eliminated through a relatively minor modification of the existing mass-flux based parameterizations. Partial evaluations of the unified parameterization are also presented. ROUTE II follows the ""multi-scale modeling framework (MMF)"" approach, which takes advantage of explicit representation of deep moist convection and associated cloud-scale processes by CRMs. The Quasi-3-D (Q3-D) MMF is an attempt to broaden the applicability of MMF without necessarily using a fully three-dimensional CRM. This is accomplished using a network of cloud-resolving grids with large gaps. An outline of the Q3-D algorithm and highlights of preliminary results are reviewed. © 2011 Author(s)."
"7005183034;7101699632;7005237645;","Multiscale storm identification and forecast",2003,"10.1016/S0169-8095(03)00068-1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0141515257&doi=10.1016%2fS0169-8095%2803%2900068-1&partnerID=40&md5=4f91f9203656ee3cbb66051226c87f5f","We describe a recently developed hierarchical K-Means clustering method for weather images that can be employed to identify storms at different scales. We describe an error-minimization technique to identify movement between successive frames of a sequence and we show that we can use the K-Means clusters as the minimization template. A Kalman filter is used to provide smooth estimates of velocity at a pixel through time. Using this technique in combination with the K-Means clusters, we can identify storm motion at different scales and choose different scales to forecast based on the time scale of interest. The motion estimator has been applied both to reflectivity data obtained from the National Weather Service Radar (WSR-88D) and to cloud-top infrared temperatures obtained from GOES satellites. We demonstrate results on both these sensors. © 2003 Elsevier B.V. All rights reserved."
"57217561201;14322460000;25649793900;23568389400;7003498065;6602815123;23018141700;6602378790;6701497749;55325066500;6506396422;6602931427;20434404100;7004496942;34876658200;6603262263;56046478800;7402889608;7202180152;7801387774;56188688000;36932594300;8673075300;","Description and evaluation of the Community Multiscale Air Quality (CMAQ) modeling system version 5.1",2017,"10.5194/gmd-10-1703-2017","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85018652965&doi=10.5194%2fgmd-10-1703-2017&partnerID=40&md5=140d4cfc6252a9078313fd413c5f3df2","The Community Multiscale Air Quality (CMAQ) model is a comprehensive multipollutant air quality modeling system developed and maintained by the US Environmental Protection Agency's (EPA) Office of Research and Development (ORD). Recently, version 5.1 of the CMAQ model (v5.1) was released to the public, incorporating a large number of science updates and extended capabilities over the previous release version of the model (v5.0.2). These updates include the following: improvements in the meteorological calculations in both CMAQ and the Weather Research and Forecast (WRF) model used to provide meteorological fields to CMAQ, updates to the gas and aerosol chemistry, revisions to the calculations of clouds and photolysis, and improvements to the dry and wet deposition in the model. Sensitivity simulations isolating several of the major updates to the modeling system show that changes to the meteorological calculations result in enhanced afternoon and early evening mixing in the model, periods when the model historically underestimates mixing. This enhanced mixing results in higher ozone (O3) mixing ratios on average due to reduced NO titration, and lower fine particulate matter (PM2. 5) concentrations due to greater dilution of primary pollutants (e.g., elemental and organic carbon). Updates to the clouds and photolysis calculations greatly improve consistency between the WRF and CMAQ models and result in generally higher O3 mixing ratios, primarily due to reduced cloudiness and attenuation of photolysis in the model. Updates to the aerosol chemistry result in higher secondary organic aerosol (SOA) concentrations in the summer, thereby reducing summertime PM2. 5 bias (PM2. 5 is typically underestimated by CMAQ in the summer), while updates to the gas chemistry result in slightly higher O3 and PM2. 5 on average in January and July. Overall, the seasonal variation in simulated PM2. 5 generally improves in CMAQv5.1 (when considering all model updates), as simulated PM2. 5 concentrations decrease in the winter (when PM2. 5 is generally overestimated by CMAQ) and increase in the summer (when PM2. 5 is generally underestimated by CMAQ). Ozone mixing ratios are higher on average with v5.1 vs. v5.0.2, resulting in higher O3 mean bias, as O3 tends to be overestimated by CMAQ throughout most of the year (especially at locations where the observed O3 is low); however, O3 correlation is largely improved with v5.1. Sensitivity simulations for several hypothetical emission reduction scenarios show that v5.1 tends to be slightly more responsive to reductions in NOx(NO+NO2), VOC and SOx (SO2+SO4) emissions than v5.0.2, representing an improvement as previous studies have shown CMAQ to underestimate the observed reduction in O3 due to large, widespread reductions in observed emissions. © Author(s) 2017."
"6701787960;7402889608;7202180152;7405728922;6701756440;","An operational evaluation of the Eta-CMAQ air quality forecast model",2006,"10.1016/j.atmosenv.2005.12.062","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33746211146&doi=10.1016%2fj.atmosenv.2005.12.062&partnerID=40&md5=fde3efa776eb8da0aed0ab2bda7a4b0f","The National Oceanic and Atmospheric Administration (NOAA), in partnership with the United States Environmental Protection Agency (EPA), are developing an operational, nationwide Air Quality Forecasting (AQF) system. An experimental phase of this program, which couples NOAA's Eta meteorological model with EPA's Community Multiscale Air Quality (CMAQ) model, began operation in June of 2004 and has been providing forecasts of ozone (O3) concentrations over the northeastern United States. An important component of this AQF system has been the development and implementation of an evaluation protocol. Accordingly, a suite of statistical metrics that facilitates evaluation of both discrete- and categorical-type forecasts was developed and applied to the system in order to characterize its performance. The results reveal that the AQF system performed reasonably well in this inaugural season (mean domain wide correlation coefficient=0.59), despite anomalously cool and wet conditions that were not conducive to the formation of O3. Due in part to these conditions, the AQF system overpredicted concentrations, resulting in a mean bias of +10.2 ppb (normalized mean bias=+22.8%). In terms of error, the domain-wide root mean square error averaged 15.7 ppb (normalized mean error=28.1%) for the period. Examination of the discrete and categorical metrics on a daily basis revealed that the AQF system's level of performance was closely related to the synoptic-scale meteorology impacting the domain. The model performed very well during periods when anticyclones, characterized by clear skies, dominated. Conversely, periods characterized by extensive cloud associated with fronts and/or cyclones, resulted in poor model performance. Subsequent analysis revealed that factors associated with CMAQ's cloud cover scheme contributed to this overprediction. Accordingly, changes to the cloud schemes are currently underway that are expected to significantly improve the AQF system's performance in anticipation of its second year of operation."
"6701905330;16643212300;","An extreme cold-air outbreak over the Labrador Sea: Roll vortices and air-sea interaction",1999,"10.1175/1520-0493(1999)127<2379:AECAOO>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033399187&doi=10.1175%2f1520-0493%281999%29127%3c2379%3aAECAOO%3e2.0.CO%3b2&partnerID=40&md5=037edbcd6b50ad13d3030051fe592e0a","Observational data from two research aircraft flights are presented. The flights were planned to investigate the air-sea interaction during an extreme cold-air outbreak, associated with the passage of a synoptic-scale low pressure system over the Labrador Sea during 8 February 1997. This is the first such aircraft-based investigation in this remote region. Both high-level dropsonde and low-level flight-level data were collected. The objectives were twofold: to map out the structure of the roll vortices that cause the ubiquitous cloud streets seen in satellite imagery, and to estimate the sensible and latent heat fluxes between the ocean and atmosphere during the event. The latter was achieved by a Lagrangian analysis of the flight-level data. The flights were part of the Labrador Sea Deep Convection Experiment, investigating deep oceanic convection, and were planned to overpass a research vessel in the area. The aircraft-observed roll vortices had a characteristic wavelength of 4-5 km, particularly evident in the water vapor signal. Unlike observations of roll vortices in other regions, a roll signature was absent from the temperature data. Analysis of satellite imagery shows the cloud streets had a characteristic wavelength of 7-10 km, indicating a multiscale roll vortex regime. There was a dramatic deepening of the boundary layer with fetch, and also with time. Off the ice edge, surface sensible heat fluxes of 500 W m-2 and surface latent heat fluxes of 100 W m-2 were measured, with uncertainties of ±20%. The very cold air is thought to be responsible for the unusually high Bowen ratio observed."
"33267959500;7101801476;35425197200;6701346974;12040633300;7003278104;7006957668;55109904700;6701845806;7402933297;7404829395;35467186900;","A multi-scale modeling system: Developments, applications, and critical issues",2009,"10.1175/2008BAMS2542.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-68949201812&doi=10.1175%2f2008BAMS2542.1&partnerID=40&md5=e8adaacd0eebecc945337c9ea0b5c368","A multiscale modeling framework (MMF), which replaces the conventional cloud parameterizations with a cloud-resolving model (CRM) in each grid column of a GCM, constitutes a new and promising approach for climate modeling. The MMF can provide for global coverage and two-way interactions between the CRMs and their parent GCM. The CRM allows for explicit simulation of cloud processes and their interactions with radiation and surface processes, and the GCM allows for global coverage. A new MMF has been developed that is based on the NASA Goddard Space Flight Center (GSFC) finite-volume GCM (fvGCM) and the Goddard Cumulus Ensemble (GCE) model. This Goddard MMF produces many features that are similar to another MMF that was developed at Colorado State University (CSU), such as an improved surface precipitation pattern, better cloudiness, improved diurnal variability over both oceans and continents, and a stronger propagating Madden-Julian oscillation (MJO) compared to their parent GCMs using traditional cloud parameterizations. Both MMFs also produce a large and positive precipitation bias in the Indian Ocean and western Pacific during the Northern Hemisphere summer. However, there are also notable differences between the two MMFs. For example, the CSU MMF simulates less rainfall over land than its parent GCM. This is why the CSU MMF simulated less overall global rainfall than its parent GCM. The Goddard MMF simulates more global rainfall than its parent GCM because of the high contribution from the oceanic component. A number of critical issues (i.e., the CRM's physical processes and its configuration) involving the Goddard MMF are discussed in this paper. © 2009 American Meteorological Society."
"23035617900;36008284700;7005276736;55900445500;","A bandelet-based inpainting technique for clouds removal from remotely sensed images",2009,"10.1109/TGRS.2008.2010454","https://www.scopus.com/inward/record.uri?eid=2-s2.0-67651180570&doi=10.1109%2fTGRS.2008.2010454&partnerID=40&md5=ce731bc53a8dac545cfce24ed3c00abf","It is well known that removing cloud-contaminated portions of a remotely sensed image and then filling in the missing data represent an important photo editing cumbersome task. In this paper, an efficient inpainting technique for the reconstruction of areas obscured by clouds or cloud shadows in remotely sensed images is presented. This technique is based on the Bandelet transform and the multiscale geometrical grouping. It consists of two steps. In the first step, the curves of geometric flow of different zones of the image are determined by using the Bandelet transform with multiscale grouping. This step allows an efficient representation of the multiscale geometry of the image's structures. Having well represented this geometry, the information inside the cloud-contaminated zone is synthesized by propagating the geometrical flow curves inside that zone. This step is accomplished by minimizing a functional whose role is to reconstruct the missing or cloud contaminated zone independently of the size and topology of the inpainting domain. The proposed technique is illustrated with some examples on processing aerial images. The obtained results are compared with those obtained by other clouds removal techniques. © 2006 IEEE."
"7202420840;57192694511;23398841900;22235943500;24082070800;","Multilevel cloud detection in remote sensing images based on deep learning",2017,"10.1109/JSTARS.2017.2686488","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85018512559&doi=10.1109%2fJSTARS.2017.2686488&partnerID=40&md5=0005957cc7563c8b3fd1a335c008035d","Cloud detection is one of the important tasks for remote sensing image processing. In this paper, a novel multilevel cloud detection method based on deep learning is proposed for remote sensing images. First, the simple linear iterative clustering (SLIC) method is improved to segment the image into good quality superpixels. Then, a deep convolutional neural network (CNN) with two branches is designed to extract the multiscale features from each superpixel and predict the superpixel as one of three classes including thick cloud, thin cloud, and noncloud. Finally, the predictions of all the superpixels in the image yield the cloud detection result. In the proposed cloud detection framework, the improved SLIC method can obtain accurate cloud boundaries by optimizing initial cluster centers, designing dynamic distance measure, and expanding search space. Moreover, different from traditional cloud detection methods that cannot achieve multilevel detection of cloud, the designed deep CNN model can not only detect cloud but also distinguish thin cloud from thick cloud. Experimental results indicate that the proposed method can detect cloud with higher accuracy and robustness than compared methods. © 2008-2012 IEEE."
"57193882808;7004279605;","A multiscale anelastic model for meteorological research",2002,"10.1175/1520-0493(2002)130<0939:AMAMFM>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036538539&doi=10.1175%2f1520-0493%282002%29130%3c0939%3aAMAMFM%3e2.0.CO%3b2&partnerID=40&md5=abd3dfb7cce185789c1bafcf1d9f5b32","The recently reported nonhydrostatic anelastic numerical model for simulating a range of atmospheric processes on scales from micro to planetary is extended to moist processes. A theoretical formulation of moist precipitating thermodynamics follows the standard cloud models; that is, it explicitly treats the formation of cloud condensate and the subsequent development and fallout of precipitation. In order to accommodate a broad range of temporal scales, the customized numerical algorithm merges the explicit scheme for the thermodynamics with the semi-implicit scheme for the dynamics, where the latter is essential for the computational efficiency of the global model. The coarse spatial resolutions used in present global models result in a disparity between the timescales of the fluid flow and the much shorter timescales associated with phase-change processes and precipitation fallout. To overcome this difficulty the approach based on the method of averages is employed, where fast processes are evaluated with adequately small time steps (and lower accuracy) over the large time step of the model, to provide an accurate approximation to the large time step integral of fast forcings in the stiff system. This approach allows for stable integrations when cloud processes are poorly resolved and it converges to the formulation standard in cloud models as the resolution increases. The theoretical developments are tested in simulations of small-, meso-, and planetary-scale idealized moist atmospheric flows. Results from the small-scale simulations demonstrate that the proposed approach compares favorably with traditional explicit techniques used in cloud models. Planetary simulations, on the other hand, illustrate an ability to capture moist processes in low-resolution large-scale flows."
"7003597952;35495958000;","Application of multiscale water and energy balance models on a tallgrass prairie",1994,"10.1029/94WR01499","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0028166227&doi=10.1029%2f94WR01499&partnerID=40&md5=3932642d3bcdaa59b4995f374b955651","The models presented in the previous paper (Famiglietti and Wood, this issue) are applied at their appropriate scales for evapotranspiration modeling at the First International Satellite Land Surface Climatology Project Field Experiment (FIFE) site. The local soil‐vegetation‐atmospheric transfer scheme is applied at five flux measurement stations in the northwest quadrant of the FIFE site. Simulations were performed for three of the four FIFE “golden (cloud‐free) days” with good results. The spatially distributed model was applied at the 11.7‐km2 King's Creek catchment, also located in the northwest quadrant of the FIFE site, during FIFE Intensive Field Campaigns (IFCs) 1–4. Simulated catchment average evapotranspiration was compared to an average of observations made at the five aforementioned measurement stations with good results. The macroscale formulation was applied to both the King's Creek catchment and the entire 15‐km FIFE site for evapotranspiration simulations. Macroscale model simulations for King's Creek were nearly identical to the spatially distributed results, implying that at this location and at this scale, the assumptions invoked in the development of the macroscale formulation are reasonable. The macroscale model was also employed to simulate evapotranspiration from the entire 15‐km site for the four golden days. Simulated evapotranspiration rates show reasonably good agreement with the 22‐station average of observations. However, it is suggested that at 15‐km and larger scales, simulation error may arise as a result of the macroscale assumptions of areally averaged atmospheric forcing, vegetation parameters, soil parameters, and the methods by which these data and other flux observations are aggregated. A methodology to combat these problems at larger scales is reviewed. Copyright 1994 by the American Geophysical Union."
"7006864972;7410221267;57034458200;56916080400;","A multiscale numerical study of Hurricane Andrew (1992). Part VI: Small-scale inner-core structures and wind streaks",2004,"10.1175/1520-0493(2004)132<1410:AMNSOH>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-3142716031&doi=10.1175%2f1520-0493%282004%29132%3c1410%3aAMNSOH%3e2.0.CO%3b2&partnerID=40&md5=03ca41439c38c946c4587b882a47da4d","The objectives of Part VI of this series of papers are to (a) simulate the finescale features of Hurricane Andrew (1992) using a cloud-resolving grid length of 2 km, (b) diagnose the formation of small-scale wind streaks, and (c) perform sensitivity experiments of varying surface fluxes on changes in storm inner-core structures and intensity. As compared to observations and a previous 6-km model run, the results show that a higher-resolution explicit simulation could produce significant improvements in the structures and evolution of the inner-core eyewall and spiral rainbands, and in the organization of convection. The eyewall becomes much more compact and symmetric with its width decreased by half, and the radius of maximum wind is reduced by ∼10 to 20 km. A zone of deep and intense potential vorticity (PV) is formed at the edge of the eye. A ring of maximum PV is collocated in regions of maximum upward motion in the eyewall and interacts strongly with the eyewall convection. The convective cores in the eyewall are associated with small-scale wind streaks. The formation of the wind streaks is diagnosed from an azimuthal momentum budget. The results reveal small-scale Lagrangian acceleration of the azimuthal flow. It is found that at the lowest model level of 40 m, the main contributor to the Lagrangian azimuthal wind tendency is the radial advection of angular momentum per unit radius. At an altitude of 1.24 km, vertical advection of the azimuthal wind, in addition to the radial advection of angular momentum per unit radius, plays important roles. Results of a series of sensitivity tests, performed to examine the impact of several critical factors in the surface and boundary layer processes on the inner-core structures and the evolution of the hurricane intensity, are presented. © 2004 American Meteorological Society."
"6507017020;7202208382;6701346974;","Convective precipitation variability as a tool for general circulation model analysis",2007,"10.1175/JCLI3991.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33846428764&doi=10.1175%2fJCLI3991.1&partnerID=40&md5=5f6f4b89457536b5f8ba63692ee10033","Precipitation variability is analyzed in two versions of the Community Atmospheric Model (CAM), the standard model, CAM, and a ""multiscale modeling framework"" (MMF), in which the cumulus parameterization has been replaced with a cloud-resolving model. Probability distribution functions (PDFs) of daily mean rainfall in three geographic locations [the Amazon Basin and western Pacific in December-February (DJF) and the North American Great Plains in June-August (JJA)] indicate that the CAM produces too much light-moderate rainfall (10 ∼ 20 mm day-1), and not enough heavy rainfall, compared to observations. The MMF underestimates rain contributions from the lightest rainfall rates but correctly simulates more intense rainfall events. These differences are not always apparent in seasonal mean rainfall totals. Analysis of 3-6-hourly rainf all and sounding data in the same locations reveals that the CAM produces moderately intense rainfall as soon as the boundary layer energizes. Precipitation is also concurrent with tropospheric relative humidity and lifted parcel buoyancy increases. In contrast, the MMF and observations are characterized by a lag of several hours between boundary layer energy buildup and precipitation, and a gradual increase in the depth of low-level relative humidity maximum prior to rainfall. The environmental entrainment rate selection in the CAM cumulus parameterization influences CAM precipitation timing and intensity, and may contribute to the midlevel dry bias in that model. The resulting low-intensity rainfall in the CAM leads to rainfall-canopy vegetation interactions that are different from those simulated by the MMF. The authors present evidence suggesting that this interaction may artificially inflate North American Great Plains summertime rainfall totals in the CAM. © 2007 American Meteorological Society."
"36538539800;35273830500;55501554900;7005665424;55113736500;","Probing into regional 03 and particulate matter pollution in the United States: 2. An examination of formation mechanisms through a process analysis technique and sensitivity study",2009,"10.1029/2009JDO11900","https://www.scopus.com/inward/record.uri?eid=2-s2.0-72049103650&doi=10.1029%2f2009JDO11900&partnerID=40&md5=6cf13ebe361c5905a719da9772a900d9","Following a comprehensive model evaluation in part 1, this part 2 paper describes results from 1 year process analysis and a number of sensitivity simulations using the Community Multiscale Air Quality (CMAQ) modeling system aimed to understand the formation mechanisms of 03 and PM 2.5 their impacts on global environment, and implications for pollution control policies. Process analyses show that the most influential processes for 03 in the planetary boundary layer (PBL) are vertical and horizontal transport, gas-phase chemistry, and dry deposition and those for PM2.5 are primary PM emissions, horizontal transport, PM processes, and cloud processes. Exports of 03 and Ox from the U.S. PBL to free troposphere occur primarily in summer and at a rate of 0.16 and 0.65 Gmoles day-1, respectively. In contrast, export of PM25 is found to occur during all seasons and at rates of 25.68-34.18 Ggrams day -1, indicating a need to monitor and control PM25 throughout the year. Among nine photochemical indicators examined, the most robust include PH2O2/PHNO3, HCHO/NOy, and HCHO/NOZ in winter and summer, H2O2/(03 + N02) in winter, and NOY in summer. They indicate a VOC-limited 03 chemistry in most areas in winter, but a NO X-limited 03 chemistry in most areas except for major cities in April-November, providing a rationale for nationwide NOX emission control and integrated control of NOX and VOCs emissions for large cities during high 03 seasons (May-September). For sensitivity of PM2.5 to its precursors, the adjusted gas ratio provides a more robust indicator than that without adjustment, especially for areas with insufficient sulfate neutralization in winter. NH4NO3 can be formed in most of the domain. Integrated control of emissions of PM precursors such as SO2, NOX, and NH3 are necessary for PM25 attainment. Among four types of VOCs examined, 03 formation is primarily affected by isoprene and low molecular weight anthropogenic VOCs, and PM25 formation is affected largely by terpenes and isoprene. Under future emission scenarios, surface 03 may increase in summer; surface P1VL 2.5 may increase or decrease. With 0.71°C increase in future surface temperatures in summer, surface 03may increase in most of the domain and surface PM 2.5may decrease in the eastern U.S. but increase in the western U.S. Copyright 2009 by the American Geophysical Union."
"56699745100;15055800700;","Comparing two methods of surface change detection on an evolving thermokarst using high-temporal-frequency terrestrial laser scanning, Selawik River, Alaska",2013,"10.3390/rs5062813","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880443513&doi=10.3390%2frs5062813&partnerID=40&md5=c237da3c801fd793dcd45ff64f65b70b","Terrestrial laser scanners (TLS) allow large and complex landforms to be rapidly surveyed at previously unattainable point densities. Many change detection methods have been employed to make use of these rich data sets, including cloud to mesh (C2M) comparisons and Multiscale Model to Model Cloud Comparison (M3C2). Rather than use simulated point cloud data, we utilized a 58 scan TLS survey data set of the Selawik retrogressive thaw slump (RTS) to compare C2M and M3C2. The Selawik RTS is a rapidly evolving permafrost degradation feature in northwest Alaska that presents challenging survey conditions and a unique opportunity to compare change detection methods in a difficult surveying environment. Additionally, this study considers several error analysis techniques, investigates the spatial variability of topographic change across the feature and explores visualization techniques that enable the analysis of this spatiotemporal data set. C2M reports a higher magnitude of topographic change over short periods of time (12 h) and reports a lower magnitude of topographic change over long periods of time (four weeks) when compared to M3C2. We found that M3C2 provides a better accounting of the sources of uncertainty in TLS change detection than C2M, because it considers the uncertainty due to surface roughness and scan registration. We also found that localized areas of the RTS do not always approximate the overall retreat of the feature and show considerable spatial variability during inclement weather; however, when averaged together, the spatial subsets approximate the retreat of the entire feature. New data visualization techniques are explored to leverage temporally and spatially continuous data sets. Spatially binning the data into vertical strips along the headwall reduced the spatial complexity of the data and revealed spatiotemporal patterns of change. © 2013 by the authors."
"7101959253;16679271700;35494005000;7005626683;7202899330;","A comparison of simulated cloud radar output from the multiscale modeling framework global climate model with CloudSat cloud radar observations",2009,"10.1029/2008JD009790","https://www.scopus.com/inward/record.uri?eid=2-s2.0-66949117429&doi=10.1029%2f2008JD009790&partnerID=40&md5=01b8dfb24e40097435ea7a5e7e622121","Over the last few years a new type of global climate model (GCM) has emerged in which a cloud-resolving model is embedded into each grid cell of a GCM. This new approach is frequently called a multiscale modeling framework (MMF) or superparameterization. In this article we present a comparison of MMF output with radar observations from the NASA CloudSat mission, which uses a near-nadir-pointing millimeter-wavelength radar to probe the vertical structure of clouds and precipitation. We account for radar detection limits by simulating the 94 GHz radar reflectivity that CloudSat would observe from the high-resolution cloud-resolving model output produced by the MMF. Overall, the MMF does a good job of reproducing the broad pattern of tropical convergence zones, subtropical belts, and midlatitude storm tracks, as well as their changes in position with the annual solar cycle. Nonetheless, the comparison also reveals a number of model shortfalls including (1) excessive hydrometeor coverage at all altitudes over many convectively active regions, (2) a lack of low-level hydrometeors over all subtropical oceanic basins, (3) excessive low-level hydrometeor coverage (principally precipitating hydrometeors) in the midlatitude storm tracks of both hemispheres during the summer season (in each hemisphere), and (4) a thin band of low-level hydrometeors in the Southern Hemisphere of the central (and at times eastern and western) Pacific in the MMF, which is not observed by CloudSat. This band resembles a second much weaker ITCZ but is restricted to low levels. Copyright 2009 by the American Geophysical Union."
"6602093215;6603810234;55263378100;","High-Mass Star and Massive Cluster Formation in the Milky Way",2018,"10.1146/annurev-astro-091916-055235","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048113220&doi=10.1146%2fannurev-astro-091916-055235&partnerID=40&md5=eb8d7807806ed1940472a3e6b912dd32","This review examines the state-of-the-art knowledge of high-mass star and massive cluster formation, gained from ambitious observational surveys, which acknowledges the multiscale characteristics of these processes. After a brief overview of theoretical models and main open issues, we present observational searches for the evolutionary phases of high-mass star formation, first among high-luminosity sources and more recently among young massive protostars and the elusive high-mass prestellar cores. We then introduce the most likely evolutionary scenario for high-mass star formation, which emphasizes the link of high-mass star formation to massive cloud and cluster formation. Finally, we introduce the first attempts to search for variations of the star-formation activity and cluster formation in molecular cloud complexes in the most extreme star-forming sites and across the Milky Way. The combination of Galactic plane surveys and high-angular resolution images with submillimeter facilities such as Atacama Large Millimeter Array (ALMA) are prerequisites to make significant progress in the forthcoming decade. Copyright © 2018 by Annual Reviews. All rights reserved."
"31067538200;6701670597;14920137300;","Clouds associated with the Madden-Julian oscillation: A new perspective from Cloudsat",2011,"10.1175/JAS-D-11-030.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-81155150762&doi=10.1175%2fJAS-D-11-030.1&partnerID=40&md5=4995af45f9518a4ba79c2b00d94aa6e9","The evolution of total cloud cover and cloud types is composited across the Madden-Julian oscillation (MJO) using CloudSat data for June 2006-May 2010. Two approaches are used to define MJO phases: 1) the local phase is determined at each longitude and time from filtered outgoing longwave radiation, and 2) the global phase is defined using a popular real-time multivariate MJO (RMM) index, which assigns the tropics to an MJO phase each day. In terms of local phase, CloudSat results show a familiar evolution of cloud type predominance: in the growing stages shallow clouds coexist with deep, intense, but narrow convective systems. Widespread cloud coverage and rainfall appear during the active phases, becoming more anvil dominated with time, and finally suppressed conditions return. Results are compared to the convectively coupled Kelvin wave, which has a similar life cycle to the MJO. Convection in the MJO tends to be modulated more by moisture variations compared to the Kelvin wave. In terms of global phases, wide deep precipitating, anvil, cumulus congestus, and altocumulus types exhibit similar eastward propagation from the Indian Ocean to the central Pacific, while the narrow deep precipitating type only propagates to the Maritime Continent. These propagating types also show coherent Western Hemisphere signals. Generally, negative Western Hemisphere anomalies occur when anomalies are positive over the Indian Ocean. In both approaches, sampling leads to pictorial renderings of actual clouds across MJO phases. These mosaics provide an objective representation of the cloud field that was unavailable before CloudSat and serve as a reminder to the complex nature of the MJO's multiscale features. © 2011 American Meteorological Society."
"7405728922;7202180152;6701756440;7402889608;6701497749;8673075300;12775486900;6602931427;7004008609;7404179087;","Evaluation of real-time PM2.5 forecasts and process analysis for PM2.5 formation over the eastern United States using the Eta-CMAQ forecast model during the 2004 ICARTT study",2008,"10.1029/2007JD009226","https://www.scopus.com/inward/record.uri?eid=2-s2.0-49349107749&doi=10.1029%2f2007JD009226&partnerID=40&md5=74356fdd99c3a9fa91dca9bd77265968","The performance of the Eta-Community Multiscale Air Quality (CMAQ) modeling system in forecasting PM2.5 and chemical species is assessed over the eastern United States with the observations obtained by aircraft (NOAA P-3 and NASA DC-8) and four surface monitoring networks (AIRNOW, IMPROVE, CASTNet and STN) during the 2004 International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) study. The results of the statistical analysis at the AIRNOW sites show that the model was able to reproduce the day-to-day and spatial variations of observed PM2.5 and captured a majority (73%) Of PM2.5 observations within a factor of 2, with normalized mean bias of -21%. The consistent underestimations in regional PM2.5 forecast at other networks (IMPROVE and STN) were mainly due to the underestimation of total carbonaceous aerosols at both urban and rural sites. The significant underestimation of the ""other"" category, which predominantly is composed of primary emitted trace elements in the current model configuration, is also one of the reasons leading to the underestimation of PM2.5 at rural sites. The systematic overestimations of SO42- both at the surface sites and aloft, in part, suggest too much SO2 cloud oxidation due to the overestimation of SO2 and H2O2 in the model. The underestimation of NH4+ at the rural sites and aloft may be attributed to the exclusion of some sources of NH3 in the emission inventory. The systematic underestimations of NO3- may result from the general overestimations of SO42-. Note that there are compensating errors among the underestimation of PM2.5 species (such as total carbonaceous aerosols) and overestimation of PM2.5 species (such as SO42-), leading to generally better performance of PM2.5 mass. The systematic underestimation of biogenic isoprene (by ∼30%) and terpene (by a factor of 4) suggests that their biogenic emissions may have been biased low, whereas the consistent overestimations of toluene by the model under the different conditions suggest that its anthropogenic emissions might be too high. The contributions of various physical and chemical processes governing the distribution of PM2.5 during this period are investigated through detailed analysis of model process budgets using the integrated process rate (IPR) analysis along back trajectories at five selected locations in Pennsylvania and Georgia. The results show that the dominant processes for PM2.5 formation and removal vary from the site to site, indicating significant spatial variability. Copyright 2008 by the American Geophysical Union."
"7003519472;7004101395;6507419808;7005934510;7004347561;","Reactive mercury in the troposphere: Model formation and results for Florida, the northeastern United States, and the Atlantic Ocean",2007,"10.1029/2006JD008227","https://www.scopus.com/inward/record.uri?eid=2-s2.0-38949196387&doi=10.1029%2f2006JD008227&partnerID=40&md5=8d02f6cfc52917db69c4cdace680afd3","We describe the development of a model for transport and photochemistry of atmospheric mercury at the regional scale, along with an application to the eastern United States and adjacent Atlantic Ocean and Gulf of Mexico, and comparison with aircraft-based measurements in Florida. The model is the Community Multiscale Air Quality model (CMAQ) with modifications to include an integrated solution for gas phase and aqueous photochemistry. The expanded chemistry includes O<inf>3</inf>, NO<inf>x</inf>, organics, sulfur, halogens and mercury. Divalent reactive gaseous mercury (RGM) is formed slowly through gas phase reactions and removed rapidly by aqueous reactions in cloud water. Model results show that elevated RGM (up to 260 pg m-3) forms intermittently over the Atlantic Ocean in air masses that have a cloud-free history. Aircraft measurements in Florida show RGM varying between 10 and 250 pg m-3 and increasing with altitude, a pattern that is consistent with model results. Ambient RGM would increase by 50% if aqueous reduction reactions were omitted. The model predicts that ambient elemental mercury and RGM anticorrelate in regions where RGM is produced photochemically and correlate in regions dominated by direct emissions. Model results also suggest positive correlations between RGM and SO<inf>2</inf>, reactive nitrogen and H<inf>2</inf>O<inf>2</inf>, which may be used to identify photochemically produced versus directly emitted RGM. RGM in the model is strongly correlated with O<inf>3</inf> during pollution events, and ozone formation from anthropogenic precursors is predicted to cause a significant increase in RGM. Copyright 2007 by the American Geophysical Union."
"9244932900;6701432911;7003667860;","Multiscale mountain waves influencing a major orographic precipitation event",2007,"10.1175/JAS3876.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-34147171158&doi=10.1175%2fJAS3876.1&partnerID=40&md5=ba69ab91f16fb1a253f7a93cd14493a0","This study combines high-resolution mesoscale model simulations and comprehensive airborne Doppler radar observations to identify kinematic structures influencing the production and mesoscale distribution of precipitation and microphysical processes during a period of heavy prefrontal orographic rainfall over the Cascade Mountains of Oregon on 13-14 December 2001 during the second phase of the Improvement of Microphysical Parameterization through Observational Verification Experiment (IMPROVE-2) field program. Airborne-based radar detection of precipitation from well upstream of the Cascades to the lee allows a depiction of terrain-induced wave motions in unprecedented detail. Two distinct scales of mesoscale wave-like air motions are identified: 1) a vertically propagating mountain wave anchored to the Cascade crest associated with strong midlevel zonal (i.e., cross barrier) flow, and 2) smaller-scale (<20-km horizontal wavelength) undulations over the windward foothills triggered by interaction of the low-level along-barrier flow with multiple ridge-valley corrugations oriented perpendicular to the Cascade crest. These undulations modulate cloud liquid water (CLW) and snow mixing ratios in the fifth-generation Pennsylvania State University-National Center for Atmospheric Research (PSUNCAR) Mesoscale Model (MM5), with modeled structures comparing favorably to radar-documented zones of enhanced reflectivity and CLW measured by the NOAA P3 aircraft. Errors in the model representation of a low-level shear layer and the vertically propagating mountain waves are analyzed through a variety of sensitivity tests, which indicated that the mountain wave's amplitude and placement are extremely sensitive to the planetary boundary layer (PBL) parameterization being employed. The effects of 1) using unsmoothed versus smoothed terrain and 2) the removal of upstream coastal terrain on the flow and precipitation over the Cascades are evaluated through a series of sensitivity experiments. Inclusion of unsmoothed terrain resulted in net surface precipitation increases of ∼4%-14% over the windward slopes relative to the smoothed-terrain simulation. Small-scale waves (<20-km horizontal wavelength) over the windward slopes significantly impact the horizontal pattern of precipitation and hence quantitative precipitation forecast (QPF) accuracy. © 2007 American Meteorological Society."
"23991212200;7006095466;55411439700;","Orogenic propagating precipitation systems over the united states in a global climate model with embedded explicit convection",2011,"10.1175/2011JAS3699.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051811479&doi=10.1175%2f2011JAS3699.1&partnerID=40&md5=d476466a7c2c56b089c12e79f0502b93","In the lee of major mountain chains worldwide, diurnal physics of organized propagating convection project onto seasonal and climate time scales of the hydrologic cycle, but this phenomenon is not represented in conventional global climate models (GCMs). Analysis of an experimental version of the superparameterized (SP) Community Atmosphere Model (CAM) demonstrates that propagating orogenic nocturnal convection in the central U.S. warm season is, however, representable in GCMs that use the embedded explicit convection model approach [i.e., multiscale modeling frameworks (MMFs)]. SP-CAM admits propagating organized convective systems in the lee of the Rockies during synoptic conditions similar to those that generate mesoscale convective systems in nature. The simulated convective systems exhibit spatial scales, phase speeds, and propagation speeds comparable to radar observations, and the genesis mechanism in the model agrees qualitatively with established conceptual models. Convective heating and condensate structures are examined on both resolved scales in SP-CAM, and coherently propagating cloud ""metastructures"" are shown to transcend individual cloud-resolving model arrays. In reconciling how this new mode of diurnal convective variability is admitted in SP-CAM despite the severe idealizations in the cloud-resolving model configuration, an updated discussion is presented of what physics may transcend the re-engineered scale interface in MMFs. The authors suggest that the improved diurnal propagation physics in SP-CAM are mediated by large-scale first-baroclinic gravity wave interactions with a prognostic organization life cycle, emphasizing the physical importance of preserving ""memory"" at the inner resolved scale. © 2011 American Meteorological Society."
"7402379980;7005565819;6603381720;14020649100;","Impact of the environmental low-level wind profile on ensemble forecasts of the 4 may 2007 Greensburg, Kansas, tornadic storm and associated mesocyclones",2012,"10.1175/MWR-D-11-00008.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84857090702&doi=10.1175%2fMWR-D-11-00008.1&partnerID=40&md5=1892d5f6fe26e67e31258f9ac50f14e4","The early tornadic phase of the Greensburg, Kansas, supercell on the evening of 4 May 2007 is simulated using a set of storm-scale (1-km horizontal grid spacing) 30-member ensemble Kalman filter (EnKF) data assimilation and forecast experiments. The Next Generation Weather Radar (NEXRAD) level-II radar data from the Dodge City, Kansas (KDDC), Weather Surveillance Radar-1988 Doppler (WSR-88D) are assimilated into the National Severe Storms Laboratory (NSSL) Collaborative Model for Multiscale Atmospheric Simulation (COMMAS). The initially horizontally homogeneous environments are initialized from one of three reconstructed soundings representative of the early tornadic phase of the storm, when a low-level jet (LLJ) was intensifying. To isolate the impact of the low-level wind profile, 0-3.5-km AGL wind profiles from Vance Air Force Base, Oklahoma (KVNX), WSR-88D velocity-azimuth display (VAD) analyses at 0130, 0200, and 0230 UTC are used. A sophisticated, double-moment bulk ice microphysics scheme is employed. For each of the three soundings, ensemble forecast experiments are initiated from EnKF analyses at various times prior to and shortly after the genesis of the Greensburg tornado (0200 UTC). Probabilistic forecasts of the mesocyclone-scale circulation(s) are generated and compared to the observed Greensburg tornado track. Probabilistic measures of significant rotation and observation-space diagnostic statistics are also calculated. It is shown that, in general, the track of the Greensburg tornado is well predicted, and forecasts improve as forecast lead time decreases. Significant variability is also seen across the experiments using different VAD wind profiles. Implications of these results regarding the choice of initial mesoscale environment, as well as for the ""Warn-on-Forecast"" paradigm for probabilistic numerical prediction of severe thunderstorms and tornadoes, are discussed. © 2012 American Meteorological Society."
"7801513232;7003641144;","METRo: A new model for road-condition forecasting in Canada",2001,"10.1175/1520-0450(2001)040<2026:MANMFR>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0035508972&doi=10.1175%2f1520-0450%282001%29040%3c2026%3aMANMFR%3e2.0.CO%3b2&partnerID=40&md5=5d10a5d0469a77c874b92625bdd07e8d","A numerical model to forecast road conditions, Model of the Environment and Temperature of Roads (METRo), has been developed to run at Canadian weather centers. METRo uses roadside observations from road weather information systems stations as input, together with meteorological forecasts from the operational Global Environmental Multiscale (GEM) model of the Canadian Meteorological Centre; the meteorologist can modify this forecast using the ""SCRIBE"" interface. METRo solves the energy balance at the road surface and the heat conduction in the road material to calculate the temperature evolution; it also accounts for water accumulation on the road in liquid and solid form. Radiative fluxes reaching the surface are taken from the GEM model in automatic mode or are parameterized as a function of cloud cover and temperature when run in manual mode. The road-condition forecast is done in three stages: initialization of the road temperature profile using past observations, coupling of the forecast with observations during the overlap period when the meteorological forecast and the roadside observations are both available, and the forecast itself. The coupling stage allows for adjusting the radiative fluxes to local conditions. Results for road temperature are presented for three stations in Ontario for a period of 3 months. The 24-h forecasts are issued 2 times per day at 0300 and 1500 LT. Overall, about one-half of the time the error in surface road temperature (verified every 20 min) is within ±2 K, and the nighttime rms error is about 2 K. The impact of the coupling stage is large and allows METRo to produce automatic forecasts almost as good as the manual ones, especially for the first few hours. When METRo is run in manual mode, several nearby stations can use the same meteorological input, saving preparation time for the meteorologist. METRo also contains a mechanism for correcting systematic errors at each station, and it is hoped that this capability will permit its application to many new sites without major adjustments."
"22934904700;55471474500;57212988186;24492188100;8618000600;9535769800;7403059580;36653408700;55711668600;55706080300;6601963213;7401945370;57218120214;","A 20-Year climatology of a NICAM AMIP-type simulation",2015,"10.2151/jmsj.2015-024","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84942018143&doi=10.2151%2fjmsj.2015-024&partnerID=40&md5=aff90a72bb63da9810621b10bc49a793","A 20-year integration by the nonhydrostatic icosahedral atmospheric model (NICAM) with a 14 km mesh was conducted for the first time to obtain a climatological mean and diurnal to interannual variability of a simulated atmosphere. Clouds were explicitly calculated using a cloud microphysics scheme without cumulus convection scheme. The simulation was performed under the atmospheric model intercomparison project-type conditions, except that sea surface temperature was nudged toward observed historical values using the slab ocean model. The results are analyzed with a focus on tropical disturbances, including tropical cyclones (TCs) and the Madden- Julian oscillation (MJO). NICAM simulates many aspects of atmospheric climatological mean state and variability. The geographical distributions of precipitation, including interannual, seasonal, and diurnal variations, are well reproduced. Zonal mean basic states, clouds, and top-of-atmosphere radiation are qualitatively simulated, though some severe biases such as underestimated low clouds, shortwave reflection, warmer surface, and tropical upper troposphere exist. TCs and MJO are the main focus of the simulation. In the simulation, TCs are detected with the objective thresholds of maximum wind speed due to the realistic intensity of simulated TCs. The seasonal march of TC genesis in each ocean basin is well simulated. The statistical property of the MJO and tropical waves is well reproduced in the space-time power spectra, consistent with previous NICAM studies. This implies that the stratospheric variability is also reproduced, as partially revealed in this study. Asian monsoon analysis shows that climatological western North Pacific monsoon onset occurs near the observed onset, and that the Baiu front is reproduced to some extent. Some significant model biases still exist, which indicates a need for further model improvements. The results indicate that a high-resolution global nonhydrostatic model has the potential to reveal multiscale phenomena in the climate system. © 2015, Meteorological Society of Japan."
"7103232039;6507213415;36168603800;36762726600;","Technological drivers in data centers and telecom systems: Multiscale thermal, electrical, and energy management",2013,"10.1016/j.apenergy.2013.02.047","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84874709125&doi=10.1016%2fj.apenergy.2013.02.047&partnerID=40&md5=45626fc817c602a5552039acbdf546a8","We identify technological drivers for tomorrow's data centers and telecommunications systems, including thermal, electrical and energy management challenges, based on discussions at the 2nd Workshop on Thermal Management in Telecommunication Systems and Data Centers in Santa Clara, California, on April 25-26, 2012. The relevance of thermal management in electronic systems is reviewed against the background of the energy usage of the information technology (IT) industry, encompassing perspectives of different sectors of the industry. The underlying drivers for progress at the business and technology levels are identified. The technological challenges are reviewed in two main categories - immediate needs and future needs. Enabling cooling techniques that are currently under development are also discussed. © 2013 Elsevier Ltd."
"56576549500;8663722500;","Cloud detection of RGB color aerial photographs by progressive refinement scheme",2014,"10.1109/TGRS.2014.2310240","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84902076061&doi=10.1109%2fTGRS.2014.2310240&partnerID=40&md5=272c5cb7b1bd4ff40c2f6b80eb1e1682","In this paper, we propose an automatic and effective cloud detection algorithm for color aerial photographs. Based on the properties derived from observations and statistical results on a large number of color aerial photographs with cloud layers, we present a novel progressive refinement scheme for detecting clouds in the color aerial photographs. We first construct a significance map which highlights the difference between cloud regions and noncloud regions. Based on the significance map and the proposed optimal threshold setting, we obtain a coarse cloud detection result which classifies the input aerial photograph into the candidate cloud regions and noncloud regions. In order to accurately detect the cloud regions from the candidate cloud regions, we then construct a robust detail map derived from a multiscale bilateral decomposition to guide us in removing noncloud regions from the candidate cloud regions. Finally, we further perform a guided feathering to achieve our final cloud detection result, which detects semitransparent cloud pixels around the boundaries of cloud regions. The proposed method is evaluated in terms of both visual and quantitative comparisons, and the evaluation results show that our proposed method works well for the cloud detection of color aerial photographs. © 1980-2012 IEEE."
"57198945375;57203579757;37861012100;7005565819;36598393700;","A comparison of multiscale GSI-based EnKF and 3DVar data assimilation using radar and conventional observations for midlatitude convective-scale precipitation forecasts",2015,"10.1175/MWR-D-14-00345.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84943413562&doi=10.1175%2fMWR-D-14-00345.1&partnerID=40&md5=3b0fc00762284f509303e9a81b23e39f","A GSI-based data assimilation (DA) system, including three-dimensional variational assimilation (3DVar) and ensemble Kalman filter (EnKF), is extended to the multiscale assimilation of both meso- and synoptic-scale observation networks and convective-scale radar reflectivity and velocity observations. EnKF and 3DVar are systematically compared in this multiscale context to better understand the impacts of differences between the DA techniques on the analyses at multiple scales and the subsequent convective-scale precipitation forecasts. Averaged over 10 diverse cases, 8-h precipitation forecasts initialized using GSI-based EnKF are more skillful than those using GSI-based 3DVar, both with and without storm-scale radar DA. The advantage from radar DA persists for ~5 h using EnKF, but only ~1 h using 3DVar. A case study of an upscale growing MCS is also examined. The better EnKF-initialized forecast is attributed to more accurate analyses of both the mesoscale environment and the storm-scale features. The mesoscale location and structure of a warm front is more accurately analyzed using EnKF than 3DVar. Furthermore, storms in the EnKF multiscale analysis are maintained during the subsequent forecast period. However, storms in the 3DVar multiscale analysis are not maintained and generate excessive cold pools. Therefore, while the EnKF forecast with radar DA remains better than the forecast without radar DA throughout the forecast period, the 3DVar forecast quality is degraded by radar DA after the first hour. Diagnostics revealed that the inferior analysis at mesoscales and storm scales for the 3DVar is primarily attributed to the lack of flow dependence and cross-variable correlation, respectively, in the 3DVar static background error covariance."
"6506848305;7103119050;","A simplified PDF parameterization of subgrid-scale clouds and turbulence for cloud-resolving models",2013,"10.1002/jame.20018","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880803350&doi=10.1002%2fjame.20018&partnerID=40&md5=dd61e48e72450a624125d98ed46049d4","Over the past decade a new type of global climate model (GCM) has emerged, which is known as a multiscale modeling framework (MMF). Colorado State University's MMF represents a coupling between the Community Atmosphere Model and the System for Atmospheric Modeling (SAM) to serve as the cloud-resolving model (CRM) that replaces traditionally parameterized convection in GCMs. However, due to the high computational expense of the MMF, the grid size of the embedded CRM is typically limited to 4 km for long-term climate simulations. With grid sizes this coarse, shallow convective processes and turbulence cannot be resolved and must still be parameterized within the context of the embedded CRM. This paper describes a computationally efficient closure that aims to better represent turbulence and shallow convective processes in coarse-grid CRMs. The closure is based on the assumed probability density function (PDF) technique to serve as the subgrid-scale (SGS) condensation scheme and turbulence closure that employs a diagnostic method to determine the needed input moments. This paper describes the scheme, as well as the formulation of the eddy length which is empirically determined from large eddy simulation (LES) data. CRM tests utilizing the closure yields good results when compared to LESs for two trade-wind cumulus cases, a transition from stratocumulus to cumulus, and continental cumulus. This new closure improves the representation of clouds through the use of SGS condensation scheme and turbulence due to better representation of the buoyancy flux and dissipation rates. In addition, the scheme reduces the sensitivity of CRM simulations to horizontal grid spacing. The improvement when compared to the standard low-order closure configuration of the SAM is especially striking. ©2013. American Geophysical Union. All Rights Reserved."
"55519994900;23991212200;7003666669;56162305900;55411439700;7202252296;","Constraining the influence of natural variability to improve estimates of global aerosol indirect effects in a nudged version of the Community Atmosphere Model 5",2012,"10.1029/2012JD018588","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84870917592&doi=10.1029%2f2012JD018588&partnerID=40&md5=aca35edc6a9188042f750b53d13c5f17","Natural modes of variability on many timescales influence aerosol particle distributions and cloud properties such that isolating statistically significant differences in cloud radiative forcing due to anthropogenic aerosol perturbations (indirect effects) typically requires integrating over long simulations. For state-of-the-art global climate models (GCM), especially those in which embedded cloud-resolving models replace conventional statistical parameterizations (i.e., multiscale modeling framework, MMF), the required long integrations can be prohibitively expensive. Here an alternative approach is explored, which implements Newtonian relaxation (nudging) to constrain simulations with both pre-industrial and present-day aerosol emissions toward identical meteorological conditions, thus reducing differences in natural variability and dampening feedback responses in order to isolate radiative forcing. Ten-year GCM simulations with nudging provide a more stable estimate of the global-annual mean net aerosol indirect radiative forcing than do conventional free-running simulations. The estimates have mean values and 95% confidence intervals of -1.19 0.02 W/m2 and -1.37 0.13 W/m 2 for nudged and free-running simulations, respectively. Nudging also substantially increases the fraction of the world's area in which a statistically significant aerosol indirect effect can be detected (66% and 28% of the Earth's surface for nudged and free-running simulations, respectively). One-year MMF simulations with and without nudging provide global-annual mean net aerosol indirect radiative forcing estimates of -0.81 W/m2 and -0.82 W/m2, respectively. These results compare well with previous estimates from three-year free-running MMF simulations (-0.83 W/m2), which showed the aerosol-cloud relationship to be in better agreement with observations and high-resolution models than in the results obtained with conventional cloud parameterizations. © 2012. American Geophysical Union. All Rights Reserved."
"7202772927;7006095466;","Multiscale cloud system modeling",2009,"10.1029/2008RG000276","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77957586906&doi=10.1029%2f2008RG000276&partnerID=40&md5=24db6f3f4ec91d7dab1fb0bf518cebb4","The central theme of this paper is to describe how cloud system resolving models (CRMs) of grid spacing ∼1 km have been applied to various important problems in atmospheric science across a wide range of spatial and temporal scales and how these applications relate to other modeling approaches. A long-standing problem concerns the representation of organized precipitating convective cloud systems in weather and climate models. Since CRMs resolve the mesoscale to large scales of motion (i.e., 10 km to global) they explicitly address the cloud system problem. By explicitly representing organized convection, CRMs bypass restrictive assumptions associated with convective parameterization such as the scale gap between cumulus and large-scale motion. Dynamical models provide insight into the physical mechanisms involved with scale interaction and convective organization. Multiscale CRMs simulate convective cloud systems in computational domains up to global and have been applied in place of contemporary convective parameterizations in global models. Multiscale CRMs pose a new challenge for model validation, which is met in an integrated approach involving CRMs, operational prediction systems, observational measurements, and dynamical models in a new international project: the Year of Tropical Convection, which has an emphasis on organized tropical convection and its global effects. © Copyright 2009 by the American Geophysical Union."
"14920137300;6701670597;","Multiscale convective wave disturbances in the tropics: Insights from a two-dimensional cloud-resolving model",2008,"10.1175/2007JAS2353.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-38849122638&doi=10.1175%2f2007JAS2353.1&partnerID=40&md5=26b43ab389fdd74d7d4983bdd4f419e1","Multiscale convective wave disturbances with structures broadly resembling observed tropical waves are found to emerge spontaneously in a nonrotating, two-dimensional cloud model forced by uniform cooling. To articulate the dynamics of these waves, model outputs are objectively analyzed in a discrete truncated space consisting of three cloud types (shallow convective, deep convective, and stratiform) and three dynamical vertical wavelength bands. Model experiments confirm that diabatic processes in deep convective and stratiform regions are essential to the formation of multiscale convective wave patterns. Specifically, upper-level heating (together with low-level cooling) serves to preferentially excite discrete horizontally propagating wave packets with roughly a full-wavelength structure in troposphere and ""dry"" phase speeds cn in the range 16-18 m s-1. These wave packets enhance the triggering of new deep convective cloud systems, via low-level destabilization. The new convection in turn causes additional heating over cooling, through delayed development of high-based deep convective cells with persistent stratiform anvils. This delayed forcing leads to an intensification and then widening of the low-level cold phases of wave packets as they move through convecting regions. Additional widening occurs when slower-moving (∼8 m s-1) ""gust front"" wave packets excited by cooling just above the boundary layer trigger additional deep convection in the vicinity of earlier convection. Shallow convection, meanwhile, provides positive forcing that reduces convective wave speeds and destroys relatively small-amplitude-sized waves. Experiments with prescribed modal wind damping establish the critical role of short vertical wavelengths in setting the equivalent depth of the waves. However, damping of deep vertical wavelengths prevents the clustering of mesoscale convective wave disturbances into larger-scale envelopes, so these circulations are important as well. © 2008 American Meteorological Society."
"7005920812;23393856300;56162305900;55405340400;7003666669;","PDF parameterization of boundary layer clouds in models with horizontal grid spacings from 2 to 16 km",2012,"10.1175/MWR-D-10-05059.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84862947106&doi=10.1175%2fMWR-D-10-05059.1&partnerID=40&md5=5e676784eb38a9e506da151491f9fd3a","Many present-day numerical weather prediction (NWP) models are run at resolutions that permit deep convection. In these models, however, the boundary layer turbulence and boundary layer cloud features are still grossly underresolved. Underresolution is also present in climate models that use a multiscale modeling framework (MMF), in which a convection-permitting model is run in each grid column of a global general circulation model. To better represent boundary layer clouds and turbulence in convection-permitting models, a parameterization was developed that models the joint probability density function (PDF) of vertical velocity, heat, and moisture. Although PDF-based parameterizations are more complex and computationally expensive than many other parameterizations, in principle PDF parameterizations have several advantages. For instance, they ensure consistency of liquid (cloud) water and cloud fraction; they avoid using separate parameterizations for different cloud types such as cumulus and stratocumulus; and they have an appropriate formulation in the ""terra incognita"" in which updrafts are marginally resolved. In this paper, an implementation of a PDF parameterization is tested to see whether it improves the simulations of a state-of-the-art convection-permitting model. The PDF parameterization used is the Cloud Layers Unified By Binormals (CLUBB) parameterization. The host cloud-resolving model used is the System for Atmospheric Modeling (SAM).SAMis run both with and withoutCLUBBimplemented in it. Simulations of two shallow cumulus (Cu) cases and two shallow stratocumulus (Sc) cases are run in a 3Dconfiguration at 2-, 4-, and 16-km horizontal grid spacings. Including CLUBB in the simulations improves some of the simulated fields-such as vertical velocity variance, horizontal wind fields, cloud water content, and drizzle water content-especially in the two Cu cases. Implementing CLUBB in SAM improves the simulations slightly at 2-km horizontal grid spacing, significantly at 4-km grid spacing, and greatly at 16-km grid spacing. Furthermore, the simulations that include CLUBB exhibit a reduced sensitivity to horizontal grid spacing. © 2012 American Meteorological Society."
"35182672800;35320163700;6507533363;55915046600;","Modeling secondary organic aerosol formation through cloud processing of organic compounds",2007,"10.5194/acp-7-5343-2007","https://www.scopus.com/inward/record.uri?eid=2-s2.0-35348999690&doi=10.5194%2facp-7-5343-2007&partnerID=40&md5=f09bbaaf1f809cb437a583b3dbaefa06","Interest in the potential formation of secondary organic aerosol (SOA) through reactions of organic compounds in condensed aqueous phases is growing. In this study, the potential formation of SOA from irreversible aqueousphase reactions of organic species in clouds was investigated. A new proposed aqueous-phase chemistry mechanism (AqChem) is coupled with the existing gas-phase Caltech Atmospheric Chemistry Mechanism (CACM) and the Model to Predict the Multiphase Partitioning of Organics (MPMPO) that simulate SOA formation. AqChem treats irreversible organic reactions that lead mainly to the formation of carboxylic acids, which are usually less volatile than the corresponding aldehydic compounds. Zero-dimensional model simulations were performed for tropospheric conditions with clouds present for three consecutive hours per day. Zero-dimensional model simulations show that 48-h average SOA formation is increased by 27% for a rural scenario with strong monoterpene emissions and 7% for an urban scenario with strong emissions of aromatic compounds, respectively, when irreversible organic reactions in clouds are considered. AqChem was also incorporated into the Community Multiscale Air Quality Model (CMAQ) version 4.4 with CACM/MPMPO and applied to a previously studied photochemical episode (3-4 August 2004) focusing on the eastern United States. The CMAQ study indicates that the maximum contribution of SOA formation from irreversible reactions of organics in clouds is 0.28 μg m-3 for 24-h average concentrations and 0.60 μg m-3 for one-hour average concentrations at certain locations. On average, domain-wide surface SOA predictions for the episode are increased by 9% when irreversible, in-cloud processing of organics is considered. Because aldehydes of carbon number greater than four are assumed to convert fully to the corresponding carboxylic acids upon reaction with OH in cloud droplets and this assumption may overestimate carboxylic acid formation from this reaction route, the present study provides an upper bound estimate of SOA formation via this pathway."
"7407016988;7004369046;6504115908;","Multiscale variability of the atmospheric mixed layer over the Western Pacific Warm Pool",2001,"10.1175/1520-0469(2001)058<2729:MVOTAM>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0035883231&doi=10.1175%2f1520-0469%282001%29058%3c2729%3aMVOTAM%3e2.0.CO%3b2&partnerID=40&md5=e240fcd949e1f06d9650316b48705c93","Sounding data from Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) have provided a first opportunity to document the variability of the atmospheric mixed layer over the western Pacific warm pool on timescales ranging from diurnal to intraseasonal. Six-hourly sounding data from four sites-the atoll Kapingamarangi and R/Vs Moana Wave, Shiyan 3, and Xiangyanghong 5-are used to determine the mixed layer depth and its thermodynamic properties. Almost three-quarters of the soundings at these four sites exhibited well-mixed structures: nearly constant profiles of potential temperature and specific humidity capped by a ∼150-m-deep entrainment zone. The majority of the remaining soundings were modified by precipitation and their associated downdrafts. It is estimated that approximately 40%-50% of the total soundings in COARE were influenced by precipitation downdrafts. The mean mixed layer depth at the four sites was 512 m with large variations on multiple timescales. Mean depths decreased across the warm pool from west to east, consistent with the west-to-east increase in precipitation averaged over the 4-month Intensive Observing Period. Significant modulation of the mixed layer occurred on the timescale of the Madden-Julian oscillation (MJO): The mean depth was 562 m during the undisturbed, light-wind period prior to the strong westerly wind burst (WWB) associated with the December MJO; it decreased to 466 m during the heavy-rain period of the WWB, reflecting numerous, recovering precipitation downdraft wakes; and then increased to 629 m during the late stages of the WWB when precipitation had ended. Dry intrusions over the warm pool caused the mixed layer to deepen at times to 800 m and more. Since the surface buoyancy flux typically did not increase at these times, the deepening is linked to a suppression of shallow cumulus clouds by the dry air (reduced between-cloud subsidence) as well as a general reduction in the overall shower activity and associated precipitation downdrafts. Dry intrusions also acted to enhance radiative cooling in the mixed layer. A diurnal cycle in the mixed layer depth was observed, with maximum amplitude in undisturbed (mostly clear), light-wind conditions. The mixed layer was deepest and warmest in the afternoon in direct response to 1) an afternoon peak in the surface buoyancy flux, which, in turn, arose from the large diurnal cycle in SST (up to 2°-3°C) on light-wind days, and 2) absorption of solar shortwave radiation. Thus, the atmospheric mixed layer over the warm pool during undisturbed conditions behaves like that over land, albeit with a weaker diurnal cycle amplitude, but sufficient to generate an afternoon maximum in shallow cumulus clouds and precipitation. This pattern is distinct from the typical early morning maximum in rainfall during disturbed conditions over tropical oceans. Diagnosis of the mixed layer net radiative cooling rate during light-wind conditions indicates a large diurnal range, from ∼-1.5 K day-1 at midday to nearly -3 K day-1 at night."
"8658853400;7006380976;55999772700;","Cycles and propagation of deep convection over equatorial Africa",2011,"10.1175/2011MWR3500.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-80053199993&doi=10.1175%2f2011MWR3500.1&partnerID=40&md5=3828f1734fcdf184fa9e1a944cc16309","Long-term statistics of organized convection are vital to improved understanding of the hydrologic cycle at various scales. Satellite observations are used to understand the timing, duration, and frequency of deep convection in equatorial Africa, a region with some of the most intense thunderstorms. Yet little has been published about the propagation characteristics of mesoscale convection in that region. Diurnal, subseasonal, and seasonal cycles of cold cloud (proxy for convective precipitation) are examined on a continental scale. Organized deep convection consists of coherent structures that are characteristic of systems propagating under a broad range of atmospheric conditions. Convection is triggered by heating of elevated terrain, sea/land breezes, and lake breezes. Coherent episodes of convection result from regeneration of convection through multiple diurnal cycles while propagating westward. They have an average 17.6-h duration and 673 km span; most have zonal phase speeds of 8-16 m s-1. Propagating convection occurs in the presence of moderate low-level shear that is associated with the southwesterly monsoonal flow and midlevel easterly jets. Convection is also modulated by eastward-moving equatorially trapped Kelvin waves, which have phase speeds of 12-22m s-1 over equatorial Africa. Westward propagation of mesoscale convection is interrupted by the dry phase of convectively coupled Kelvin waves. During the wet phase, daily initiation and westward propagation continues within the Kelvin wave and the cold cloud shields are larger. Mesoscale convection is more widespread during the active phase of the Madden-Julian oscillation (MJO) but with limited westward propagation. The study highlights multiscale interaction as a major source of variability in convective precipitation during the critical rainy seasons in equatorial Africa. © 2011 American Meteorological Society."
"9535769800;7202954964;8962699100;25647939800;7401945370;","Multiscale organization of convection simulated with explicit cloud processes on an aquaplanet",2007,"10.1175/JAS3948.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-34347405157&doi=10.1175%2fJAS3948.1&partnerID=40&md5=8ad26dc98c144a7a21c356b49b81e4c4","This study investigated the multiscale organization of tropical convection on an aquaplanet in a model experiment with a horizontal mesh size of 3.5 km (for a 10-day simulation) and 7 km (for a 40-day simulation), The numerical experiment used the nonhydrostatic icosahedral atmospheric model (NICAM) with explicit cloud physics. The simulation realistically reproduced multiscale cloud systems: eastward-propagating super cloud clusters (SCCs) contained westward-propagating cloud clusters (CCs). SCCs (CCs) had zonal sizes of several thousand (hundred) kilometers, typical propagation speed was 17 (10) m s-1. Smaller convective structures such as mesoscale cloud systems (MCs) of 0(10 km) and cloud-scale elements (&lt;10 km) were reproduced. A squall-type cluster with high cloud top (z &gt; 16 km) of O(100 km) area was also reproduced. Planetary-scale equatorial waves (with wavelengths of 10 000 and 40 000 km) had a major influence on the eastward propagation of the simulated SCC; destabilization east of the SCC facilitated generation of new CCs at the eastern end of the SCC. Large-scale divergence fields associated with the waves enhanced the growth of deep clouds in the CCs. A case study of a typical SCC showed that the primary mechanism forcing westward propagation varies with the life stages of the CCs or with vertical profiles of zonal wind. Cold pools and synoptic-scale waves both affected CC organization. Cloud-scale elements systematically formed along the edges of cold pools to sustain simulated MCs. The location, movement, and duration of the MCs varied with the large-scale conditions. © 2007 American Meteorological Society."
"22936054800;25649651700;7004480520;6701751765;","Gravity waves, cold pockets and CO2 clouds in the Martian mesosphere",2012,"10.1029/2011GL050343","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84856138054&doi=10.1029%2f2011GL050343&partnerID=40&md5=a19f69a58f287af3551681fb0f78d926","Many independent measurements have shown that extremely cold temperatures are found in the Martian mesosphere. These mesospheric ""cold pockets"" may result from the propagation of atmospheric waves. Recent observational achievements also hint at such cold pockets by revealing mesospheric clouds formed through the condensation of CO2, the major component of the Martian atmosphere. Thus far, modeling studies addressing the presence of cold pockets in the Martian mesosphere have explored the influence of large-scale circulations. Mesoscale phenomena, such as gravity waves, have received less attention. Here we show through multiscale meteorological modeling that mesoscale gravity waves could play a key role in the formation of mesospheric cold pockets propitious to CO2 condensation. © 2012 by the American Geophysical Union."
"7102702645;57209208040;22936108200;35374698100;7005375485;22934191100;57196774896;7203001286;57192158845;57200790631;35448188800;57210538699;","GEM-AQ, an on-line global multiscale chemical weather modelling system: Model description and evaluation of gas phase chemistry processes",2008,"10.5194/acp-8-3255-2008","https://www.scopus.com/inward/record.uri?eid=2-s2.0-46249097167&doi=10.5194%2facp-8-3255-2008&partnerID=40&md5=1cbdf76cdf032f9c41ccc05d4015ba21","Tropospheric chemistry and air quality processes were implemented on-line in the Global Environmental Multiscale weather prediction model. The integrated model, GEM-AQ, was developed as a platform to investigate chemical weather at scales from global to urban. The current chemical mechanism is comprised of 50 gas-phase species, 116 chemical and 19 photolysis reactions, and is complemented by a sectional aerosol module with 5 aerosols types. All tracers are advected using the semi-Lagrangian scheme native to GEM. The vertical transport includes parameterized subgrid-scale turbulence and large scale deep convection. Dry deposition is included as a flux boundary condition in the vertical diffusion equation. Wet deposition of gas-phase species is treated in a simplified way, and only below-cloud scavenging is considered. The emissions used include yearly-averaged anthropogenic, and monthly-averaged biogenic, ocean, soil, and biomass burning emission fluxes, as well as NOx from lightning. In order to evaluate the ability to simulate seasonal variations and regional distributions of trace gases such as ozone, nitrogen dioxide and carbon monoxide, the model was run for a period of five years (2001ĝ€"" 2005) on a global uniform 1.5°×1.5° horizontal resolution domain and 28 hybrid levels extending up to 10 hPa. Model results were compared with observations from satellites, aircraft measurement campaigns and balloon sondes. We find that GEM-AQ is able to capture the spatial details of the chemical fields in the middle and lower troposphere. The modelled ozone consistently shows good agreement with observations, except over tropical oceans. The comparison of carbon monoxide and nitrogen dioxide with satellite measurements emphasizes the need for more accurate, year-specific emissions fluxes for biomass burning and anthropogenic sources. Other species also compare well with available observations."
"7005877775;7103373860;7005626683;","Analysis of tropical radiative heating profiles: A comparison of models and observations",2007,"10.1029/2006JD008290","https://www.scopus.com/inward/record.uri?eid=2-s2.0-34548753468&doi=10.1029%2f2006JD008290&partnerID=40&md5=0965ec745bb2d25397517c5196a3aeb3","The vertical distribution of radiative heating in the atmosphere is an important driver of atmospheric circulation. Evaluation of model simulations of the Earth's radiation budget typically focus only on performance at the top of the atmosphere or at the surface. In this study, we compare the vertical distribution of cloud properties and radiative heating rates calculated from observations at the Department of Energy's Atmospheric Radiation Measurement (ARM) sites on the islands of Nauru and Manus to simulations performed using the Multiscale Modeling Framework (MMF) and the Community Atmosphere Model (CAM). Significant differences are found in the vertical profiles and diurnal cycle of cloud amount, condensed water content, and cloud effect on heating rates between the two models and between the models and the observations. The differences in the heating rates between the models and ARM results depend partly on the details of the parameterization of effective radius and absorption coefficients used and partly on differences in cloud frequency, vertical location of clouds, and optical thickness. Since the same radiative model is used in the CAM and MMF, differences in the effect of clouds on heating rates between the two models are due to the differing treatment of cloud processes in the models and the interaction of clouds and radiation on the local scale in the MMF. Copyright 2007 by the American Geophysical Union."
"7103126833;36643323800;7202343918;6603109490;7102598804;7403483250;7404458295;57211327514;7005532040;6701636478;8634803300;7403215206;55393913800;","An operational multiscale hurricane forecasting system",2002,"10.1175/1520-0493(2002)130<1830:AOMHFS>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036645978&doi=10.1175%2f1520-0493%282002%29130%3c1830%3aAOMHFS%3e2.0.CO%3b2&partnerID=40&md5=95b7fff7c4387e068593230f7eeedc95","The Operational Multiscale Environment model with Grid Adaptivity (OMEGA) is an atmospheric simulation system that links the latest methods in computational fluid dynamics and high-resolution gridding technologies with numerical weather prediction. In the fall of 1999. OMEGA was used for the first time to examine the structure and evolution of a hurricane (Floyd, 1999). The first simulation of Floyd was conducted in an operational forecast mode: additional simulations exploiting both the static as well as the dynamic grid adaptation options in OMEGA were performed later as part of a sensitivity-capability study. While a horizontal grid resolution ranging from about 120 km down to about 40 km was employed in the operational run, resolutions down to about 15 km were used in the sensitivity study to explicitly model the structure of the inner core. All the simulations produced very similar storm tracks and reproduced the salient features of the observed storm such as the recurvature off the Florida coast with an average 48-h position error of 65 km. In addition. OMEGA predicted the landfall near Cape Fear. North Carolina, with an accuracy of less than 100 km up to 96 h in advance. It was found that a higher resolution in the eyewall region of the hurricane, provided by dynamic adaptation, was capable of generating better-organized cloud and flow fields and a well-defined eye with a central pressure lower than the environment by roughly 50 mb. Since that time, forecasts were performed for a number of other storms including Georges (1998) and six 2000 storms (Tropical Storms Beryl and Chris, Hurricanes Debby and Florence. Tropical Storm Helene, and Typhoon Xangsane). The OMEGA mean track error for all of these forecasts of 101, 140, and 298 km at 24, 48, and 72 h, respectively, represents a significant improvement over the National Hurricane Center (NHC) 1998 average of 156, 268, and 374 km, respectively. In a direct comparison with the GFDL model, OMEGA started with a considerably larger position error yet came within 5% of the GFDL 72-h track error. This paper details the simulations produced and documents the results, including a comparison of the OMEGA forecasts against satellite data, observed tracks, reported pressure lows and maximum wind speed, and the rainfall distribution over land."
"9239331500;56009810800;7007068469;7005084110;56421663700;7101844867;","The pan-canadian high resolution (2.5 km) deterministic prediction system",2016,"10.1175/WAF-D-16-0035.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85002926168&doi=10.1175%2fWAF-D-16-0035.1&partnerID=40&md5=c196f47592978e0dded3a31cda2b917a","Since November 2014, the Meteorological Services of Canada (MSC) has been running a real-time numerical weather prediction system that provides deterministic forecasts on a regional domain with a 2.5-km horizontal grid spacing covering a large portion of Canada using the Global Environmental Multiscale (GEM) forecast model. This system, referred to as the High Resolution Deterministic Prediction System (HRDPS), is currently downscaled from MSC's operational 10-km GEM-based regional system but uses initial surface fields from a high-resolution (2.5 km) land data assimilation system coupled to the HRDPS and initial hydrometeor fields from the forecast of a 2.5-km cycle, which reduces the spinup time for clouds and precipitation. Forecast runs of 48 h are provided four times daily. The HRDPS was tested and compared to the operational 10-km system. Model runs from the two systems were evaluated against surface observations for common weather elements (temperature, humidity, winds, and precipitation), fractional cloud cover, and also against upper-air soundings, all using standard metrics. Although the predictions of some fields were degraded in some specific regions, the HRDPS generally outperformed the operational system for a majority of the scores. The evaluation illustrates the added value of the 2.5-km model and the potential for improved numerical guidance for the prediction of high-impact weather. © 2016 American Meteorological Society."
"7402966606;7404970050;","Evolution of multiscale vortices in the development of Hurricane Dolly (2008)",2011,"10.1175/2010JAS3522.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-78651070017&doi=10.1175%2f2010JAS3522.1&partnerID=40&md5=2f93721ad0b6326da0be44ab1bb00587","As a follow-up to a previously published article on the initial development and genesis of Hurricane Dolly (2008), this study further examines the evolution of, and interactions among, multiscale vortices ranging from the system-scale main vortex (L > 150 km) to the intermediate-scale cloud clusters (50 km < L < 150 km) and individual vorticity-rich convective cells (L < 50 km). It is found that there are apparent self-similarities among these vortices at different scales, each of which may undergo several cycles of alternating accumulation and release of convective available potential energy. Enhanced surface fluxes below individual cyclonic vortices at each scale contribute to the sustainment and reinvigoration of moist convection that in turn contributes to the maintenance and upscale growth of these vortices. Spectral analysis of horizontal divergence and relative vorticity further suggests that the cloud-cluster-scale and system-scale vortices are predominantly balanced while the individual convective vortices are largely unbalanced. The vorticity and energy produced by these individual vorticity-rich convective cells first saturate at convective scales that are subsequently transferred to larger scales. The sum of the diabatic heating released from these convective cells may be regarded as a persistent forcing on the quasi-balanced system-scale vortex. The secondary circulation induced by such forcing converges the cluster- and convective-scale vorticity anomalies into the storm center region. Convergence and projections of the smaller-scale vorticity to the larger scales eventually produce the spinup of the system-scale vortex. Meanwhile, convectively induced negative vorticity anomalies also converge toward the storm center, which are weaker and shorter lived, and thus are absorbed rather than expelled. © 2011 American Meteorological Society."
"9132948500;7402064802;11940701600;8525144100;7101959253;16679271700;18936046300;52464731300;7005626683;","On the diurnal cycle of deep convection, high-level cloud, and upper troposphere water vapor in the Multiscale Modeling Framework",2008,"10.1029/2008JD009905","https://www.scopus.com/inward/record.uri?eid=2-s2.0-56249143166&doi=10.1029%2f2008JD009905&partnerID=40&md5=993186e929d04d425fc13f901bbf1e7d","The Multiscale Modeling Framework (MMF), also. called ""superparameterization"", embeds a cloud-resolving model (CRM) at each grid column of a general circulation model to replace traditional parameterizations of moist convection and large-scale condensation. This study evaluates the diurnal cycle of deep convection, high-level clouds, and upper troposphere water vapor by applying an infrared (IR) brightness temperature (T<inf>b</inf>) and a precipitation radar (PR) simulator to the CRM column data. Simulator results are then compared with IR radiances from geostationary satellites and PR reflectivities from the Tropical Rainfall Measuring Mission (TRMM). While the actual surface precipitation rate in the MMF has a reasonable diurnal phase and amplitude when compared with TRMM observations, the IR simulator results indicate an inconsistency in the diurnal anomalies of high-level clouds between the model and the geostationary satellite data. Primarily because of its excessive high-level clouds, the MMF overestimates the simulated precipitation index (PI) and fails to reproduce the observed diurnal cycle phase relationships among PI, high-level clouds, and upper troposphere relative humidity. The PR simulator results show that over the tropical oceans, the occurrence fraction of reflectivity in excess of 20 dBZ is almost 1 order of magnitude larger than the TRMM data especially at altitudes above 6 km. Both results suggest that the MMF oceanic convection is overactive and possible reasons for this bias are discussed. However, the joint distribution of simulated IR T<inf>b</inf> and PR reflectivity indicates that the most intense deep convection is found more often over tropical land than ocean, in agreement with previous observational studies. Copyright 2008 by the American Geophysical Union."
"7004978125;","Multiscale model with moisture and systematic strategies for superparameterization",2007,"10.1175/JAS3976.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-34547729090&doi=10.1175%2fJAS3976.1&partnerID=40&md5=326a82a895e574f82450c44382231459","The accurate parameterization of moist convection presents a major challenge for the accurate prediction of weather and climate through numerical models. Superparameterization is a promising recent alternative strategy for including the effects of moist convection through explicit turbulent fluxes calculated from a cloud-resolving model. Basic scales for cloud-resolving modeling are the microscales on the order of 10 km in space on time scales on the order of 15 min, where vertical and horizontal motions are comparable and moist processes are strongly nonlinear (meso-gamma scale). In this paper, systematic multiscale asymptotic analysis is utilized to develop simplified microscale mesoscale dynamic (MMD) models for interaction between the microscales and spatiotemporal mesoscales on the order of 100 km and 2.5 h (meso-beta scale). The new MMD models lead to a systematic framework for superparameterization for numerical weather prediction (NWP) generalizing the traditional column modeling framework. The MMD formulation also provides a flexible systematic framework for devising new parameterization strategies for NWP intermediate between the two extremes of column modeling and detailed cloud-resolving modeling. It is also established here that these MMD models fit crudely into the recent systematic multiscale framework developed to explain the observed larger-scale statistical self-similarity of tropical convection, and therefore provide a systematic framework for superparameterization. Finally, it is shown that the new MMD models have the structure of a heterogeneous multiscale method so that many numerical techniques recently developed in the applied mathematics literature can be applied to this formulation. © 2007 American Meteorological Society."
"55271575700;7003875618;7202205546;7006461606;57210538699;","Multi-scale model analysis of boundary layer ozone over East Asia",2009,"10.5194/acp-9-3277-2009","https://www.scopus.com/inward/record.uri?eid=2-s2.0-74049095322&doi=10.5194%2facp-9-3277-2009&partnerID=40&md5=d0f56fa778939897f480e27803d6cdf5","This study employs the regional Community Multiscale Air Quality (CMAQ) model to examine seasonal and diurnal variations of boundary layer ozone (O 3) over East Asia. We evaluate the response of model simulations of boundary layer O3 to the choice of chemical mechanisms, meteorological fields, boundary conditions, and model resolutions. Data obtained from surface stations, aircraft measurements, and satellites are used to advance understanding of O3 chemistry and mechanisms over East Asia and evaluate how well the model represents the observed features. Satellite measurements and model simulations of summertime rainfall are used to assess the impact of the Asian monsoon on O3 production. Our results suggest that summertime O3 over Central Eastern China is highly sensitive to cloud cover and monsoonal rainfall over this region. Thus, accurate simulation of the East Asia summer monsoon is critical to model analysis of atmospheric chemistry over China. Examination of hourly summertime O3 mixing ratios from sites in Japan confirms the important role of diurnal boundary layer fluctuations in controlling ground-level O3. By comparing five different model configurations with observations at six sites, the specific mechanisms responsible for model behavior are identified and discussed. In particular, vertical mixing, urban chemistry, and dry deposition depending on boundary layer height strongly affect model ability to capture observed behavior. Central Eastern China appears to be the most sensitive region in our study to the choice of chemical mechanisms. Evaluation with TRACE-P aircraft measurements reveals that neither the CB4 nor the SAPRC99 mech-Correspondence to: M. Lin (mlin26@wisc.edu) anisms consistently capture observed behavior of key photochemical oxidants in springtime. However, our analysis finds that SAPRC99 performs somewhat better in simulating mixing ratios of H 2O2 (hydrogen peroxide) and PAN (peroxyacetyl nitrate) at flight altitudes below 1 km. The high level of uncertainty associated with O3 production in Central Eastern China poses a major problem for regional air quality management. This highly polluted, densely populated region would greatly benefit from comprehensive air quality monitoring and the development of model chemical mechanisms appropriate to this unique atmospheric environment."
"7801576203;7006429360;7005565819;55790233000;13204740600;","Storm-scale data assimilation and ensemble forecasts for the 27 April 2011 severe weather outbreak in Alabama",2015,"10.1175/MWR-D-14-00268.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84943428468&doi=10.1175%2fMWR-D-14-00268.1&partnerID=40&md5=54ef90c426e6c52e26ed397f878e0e94","As part of NOAA's Warn-on-Forecast (WoF) initiative, a multiscale ensemble-based assimilation and prediction system is developed using the WRF-ARW model and DART assimilation software. To evaluate the capabilities of the system, retrospective short-range probabilistic storm-scale (convection allowing) ensemble analyses and forecasts are produced for the 27 April 2011 Alabama severe weather outbreak. Results indicate that the storm-scale ensembles are able to analyze the observed storms with strong low-level rotation at approximately the correct locations and to retain the supercell structures during the 0-1-h forecasts with reasonable accuracy. The system predicts the low-level mesocyclones of significant isolated tornadic supercells that align well with the locations of radar-derived rotation. For cases with multiple interacting storms in close proximity, the system tends to produce more variability in mesocyclone forecasts from one initialization time to the next until the observations show the dominance of one of the cells. The short-range ensemble probabilistic forecasts obtained from this continuous 5-min storm-scale 6-h-long update system demonstrate the potential of a frequently updated, high-resolution NWP system that could be used to extend severe weather warning lead times. This study also demonstrates the challenges associated with developing a WoF-type system. The results motivate future work to reduce model errors associated with storm motion and spurious cells, and to design storm-scale ensembles that better represent typical 1-h forecast errors."
"16241933300;7404327420;7005054220;57034458200;23013116500;7101638253;","Impact of fair-weather cumulus clouds and the Chesapeake Bay breeze on pollutant transport and transformation",2011,"10.1016/j.atmosenv.2011.04.003","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79959500250&doi=10.1016%2fj.atmosenv.2011.04.003&partnerID=40&md5=6ad90d3b3308789125b27fd472911562","Two fine-scale meteorological processes, fair-weather cumulus cloud development and a bay breeze, are examined along with their impacts on air chemistry. The impact of model resolution on fair-weather cumulus cloud development, transport of pollutants through clouds, sulfur dioxide to sulfate conversion in clouds, and the development of the Chesapeake Bay breeze are examined via 13.5, 4.5, 1.5, and 0.5 km resolution simulations covering the Washington - Baltimore area. Results show that as the resolution increases, more pollutants are transported aloft through fair-weather cumulus clouds causing an increase in the rate of oxidation of sulfur dioxide to sulfate aerosols. The high resolution model runs more nearly match observations of a local pollutant maximum near the top of the boundary layer and produce an increase in boundary layer venting with subsequent pollutant export. The sensitivity of sulfur dioxide to sulfate conversion rates to cloud processing is examined by comparing sulfur dioxide and sulfate concentrations from simulations that use two different methods to diagnose clouds. For this particular event, a diagnostic method produces the most clouds and the most realistic cloud cover, has the highest oxidation rates, and generates sulfur dioxide and sulfate concentrations that agree best with observations. The differences between the simulations show the importance of accurately simulating clouds in sulfate simulations. The fidelity of the model's representation of the bay breeze is examined as a function of resolution. As the model resolution increases, a larger temperature gradient develops along the shoreline of the Chesapeake Bay causing the bay breeze to form sooner, push farther inland, and loft more pollutants upward. This stronger bay breeze results in low-level convergence, a buildup of near surface ozone over land and a decrease in the land-to-sea flux of ozone and ozone precursors as seen in measurements. The resulting 8 h maximum ozone concentration over the Bay is 10 ppbv lower in the 0.5 km simulation than in the 13.5 km simulation. © 2011 Elsevier Ltd."
"55823622600;6507497737;13407438100;13407174600;55429634900;7006767800;","Numerical experiments on MM5-CMAQ sensitivity to various PBL schemes",2006,"10.1016/j.atmosenv.2005.12.055","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33646476193&doi=10.1016%2fj.atmosenv.2005.12.055&partnerID=40&md5=12642010e9ea53de2ac7aa5384018fdc","The Community Multiscale Air Quality (CMAQ) modeling system developed by the United States Environmental Protection Agency (USEPA) was used along with the PSU/NCAR mesoscale modeling system MM5 to study air quality modeling sensitivity to various planetary boundary layer (PBL) schemes implemented in MM5. Two 37-day periods, representing typical summer and winter periods, were selected for the simulations. The MM5 domain covered the continental US while the CMAQ domain covered much of the central and eastern US. There were 34 vertical layers in MM5 and 18 in CMAQ. The horizontal resolution was 36 km for both. MM5 was run with five of the seven commonly used PBL schemes to generate a series of gridded meteorological fields. The data were then processed and converted by the meteorology-chemistry interface processor (MCIP) to produce meteorological input for CMAQ, in conjunction with the emissions data prepared by the Sparse Matrix Operator Kernel Emissions (SMOKE) System. The sensitivity of MM5-CMAQ modeling to the various PBL schemes was assessed and quantified by comparing model output against observations from the meteorological and the air quality monitoring networks within the CMAQ domain. The meteorological variables evaluated included surface (2-m) and 850-mb temperature, 10-meter and 850 mb wind speed and direction, 2-m mixing ratio, surface pressure, and cloud fraction over 50 surface sites and 21 upper air sounding sites. The CMAQ variables included gaseous species O3, NO2, NOx, SO2 and fine particulate matter PM2.5 for over 2000 monitoring stations. A new 3-2-1 objective evaluation approach was developed to enhance the model sensitivity analysis. Results of evaluation of these variables indicate that domain-wide the performance of neither model was sensitive to the PBL schemes. Although large differences of PBL height existed across the meteorological simulations, they did not appreciably affect the CMAQ performance. On an urban scale, differences across the CMAQ simulations were large enough for the model to be considered sensitive, although no favorable PBL scheme was identified. It is suggested that domain-wide the lack of sensitivity of the MM5-CMAQ modeling system to the PBL schemes was mainly attributed to the parameterization of vertical eddy diffusivity in CMAQ and the four-dimensional data assimilation (FDDA) in MM5. © 2006 Elsevier Ltd. All rights reserved."
"56962915800;55717347500;","A model for scale interaction in the Madden-Julian oscillation",2011,"10.1175/2011JAS3660.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-81555213059&doi=10.1175%2f2011JAS3660.1&partnerID=40&md5=a7a32d1375eeb5117639023058498a6d","The Madden-Julian oscillation (MJO) is an equatorial planetary-scale circulation system coupled with a multiscale convective complex, and it moves eastward slowly (about 5 m s-1) with a horizontal quadrupole vortex and vertical rearward-tilted structure. The nature and role of scale interaction (SI) is one of the elusive aspects of the MJO dynamics. Here a prototype theoretical model is formulated to advance the current understanding of the nature of SI in MJO dynamics. The model integrates three essential physical elements: (a) large-scale equatorial wave dynamics driven by boundary layer frictional convergence instability (FCI), (b) effects of the upscale eddy momentum transfer (EMT) by vertically tilted synoptic systems resulting from boundary layer convergence and multicloud heating, and (c) interaction between planetary-scale wave motion and synoptic-scale systems (the eastward-propagating super cloud clusters and westward-propagating 2-day waves). It is shown that the EMT mechanism tends to yield a stationary mode with a quadrupole vortex structure (enhanced Rossby wave component), whereas the FCI yields a relatively fast eastward-moving and rearward-tilted Gill-like pattern (enhanced Kelvin wave response). The SI instability stems from corporative FCI orEMTmechanisms, and its property is a mixture of FCI andEMTmodes. The properties of the unstable modes depend on the proportion of deep convective versus stratiform/congestus heating or the ratio of deep convective versus total amount of heating. With increasing stratiform/congestus heating, the FCI weakens while the EMT becomes more effective. A growing SI mode has a horizontal quadrupole vortex and rearwardtilted structure and prefers slow eastward propagation, which resembles the observed MJO. The FCI sets the rearward tilt and eastward propagation, while the EMT slows down the propagation speed. The theoretical results presented here point to the need to observe multicloud structure and vertical heating profiles within the MJO convective complex and to improve general circulation models' capability to reproduce correct partitioning of cloud amounts between deep convective and stratiform/congestus clouds. Limitations and future work are also discussed. © 2010 American Meteorological Society."
"6507506899;25953950400;","Multiscale evolution of a derecho-producing mesoscale convective system",1998,"10.1175/1520-0493(1998)126<2991:MEOADP>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032999103&doi=10.1175%2f1520-0493%281998%29126%3c2991%3aMEOADP%3e2.0.CO%3b2&partnerID=40&md5=f26b993e808d8fd09b8ca1816ecc00d6","In this paper the authors address one type of severe weather: strong straight-line winds. The case of a mesoscale convective system that developed in eastern Colorado on 12-13 May 1985 was studied. The system formed in the afternoon, was active until early morning, and caused strong winds during the night. A multiscale nonhydrostatic full physics simulation was performed to formulate a conceptual model of the main airflow branches of the system, and to gain understanding of the physical processes involved in the strong wind generation in this storm. Four telescopically nested grids covering from the synoptic-scale down to cloud-scale circulations were used. A Lagrangian model was employed to follow trajectories of parcels that took part in the updraft and downdraft, and balances of forces were computed along the trajectories. The strong nocturnal winds were caused by downdrafts reaching the surface and by a dynamically forced horizontal pressure gradient force. The most important branch of the downdraft had an ""up-down"" trajectory. Parcels originated close to the ground, were lifted up by a strong upward-directed pressure gradient force, and became colder than their surroundings as they ascended in a stable environment. Then, as they went through the precipitation shaft, they sank due to negative buoyancy enhanced by condensate loading. The upward pressure gradient force was partially related to midlevel perturbation vorticity in the storm."
"36538539800;36065603800;27171906700;55113736500;7005956394;7402822814;7405728922;6701756440;","A comparative study of nucleation parameterizations: 2. Three-dimensional model application and evaluation",2010,"10.1029/2010JD014151","https://www.scopus.com/inward/record.uri?eid=2-s2.0-78149289941&doi=10.1029%2f2010JD014151&partnerID=40&md5=82b44e6093e6d80289461f116283ed8b","Following the examination and evaluation of 12 nucleation parameterizations presented in part 1, 11 of them representing binary, ternary, kinetic, and cluster-activated nucleation theories are evaluated in the U.S. Environmental Protection Agency Community Multiscale Air Quality (CMAQ) modeling system version 4.4. The 12-28 June 1999 Southern Oxidants Study episode is selected as a testbed to evaluate simulated particulate matter (PM) number and size predictions of CMAQ with different nucleation parameterizations. The evaluation shows that simulated domain-wide maximum PM<inf>2.5</inf> number concentrations with different nucleation parameterizations can vary by 3 orders of magnitude. All parameterizations overpredict (by a factor of 1.4 to 1.7) the total number concentrations of accumulation-mode PM and significantly underpredict (by factors of 1.3 to 65.7) those of Aitken-mode PM, resulting in a net underprediction (by factors of 1.3 to 13.7) of the total number concentrations of PM<inf>2.5</inf> under a polluted urban environment at a downtown station in Atlanta. The predicted number concentrations for Aitken-mode PM at this site can vary by up to 3 orders of magnitude, and those for accumulation-mode PM can vary by up to a factor of 3.2, with the best predictions by the power law of Sihto et al. (2006) (NMB of -31.7%) and the worst predictions by the ternary nucleation parameterization of Merikanto et al. (2007) (NMB of -93.1%). The ternary nucleation parameterization of Napari et al. (2002) gives relatively good agreement with observations but for a wrong reason. The power law of Kuang et al. (2008) and the binary nucleation parameterization of Harrington and Kreidenweis (1998) give better agreement than the remaining parameterizations. All the parameterizations fail to reproduce the observed temporal variations of PM number, volume, and surface area concentrations. The significant variation in the performance of these parameterizations is caused by their different theoretical bases, formulations, and dependence on temperature, relative humidity, and the ambient levels of H<inf>2</inf>SO<inf>4</inf> and NH <inf>3</inf>. The controlling processes are different for PM number, mass, and surface areas. At urban/rural locations, some PM processes (e.g., homogeneous nucleation) and/or vertical transport may dominate the production of PM <inf>2.5</inf> number, and emissions, or PM processes, or vertical transport or their combinations may dominate the production of PM<inf>2.5</inf> mass and surface area. Dry deposition or some PM processes such as coagulation may dominate PM<inf>2.5</inf> number loss, and horizontal and vertical transport, and cloud processes (e.g., cloud scavenging and wet deposition) may dominate the loss of PM<inf>2.5</inf> mass and surface area concentrations. Sensitivity simulations show that the PM number and size distribution predictions are most sensitive to prescribed emission fractions of Aitken and accumulation-mode PM and the assumed initial PM size distribution, in addition to different nucleation parameterizations. Copyright 2010 by the American Geophysical Union."
"56957268600;7102001327;6701553081;15030837600;","A regional ensemble prediction system based on moist targeted singular vectors and stochastic parameter perturbations",2008,"10.1175/2007MWR2109.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-44449163411&doi=10.1175%2f2007MWR2109.1&partnerID=40&md5=6a23ad7b93fa7ba7cc5fe55cd6104e3c","A regional ensemble prediction system (REPS) with the limited-area version of the Canadian Global Environmental Multiscale (GEM) model at 15-km horizontal resolution is developed and tested. The total energy norm singular vectors (SVs) targeted over northeastern North America are used for initial and boundary perturbations. Two SV perturbation strategies are tested: dry SVs with dry simplified physics and moist SVs with simplified physics, including stratiform condensation and convective precipitation as well as dry processes. Model physics uncertainties are partly accounted for by stochastically perturbing two parameters: the threshold vertical velocity in the trigger function of the Kain-Fritsch deep convection scheme, and the threshold humidity in the Sundqvist explicit scheme. The perturbations are obtained from first-order Markov processes. Short-range ensemble forecasts in summer with 16 members are performed for five different experiments. The experiments employ different perturbation and piloting strategies, and two different surface schemes. Verification focuses on quantitative precipitation forecasts and is done using a range of probabilistic measures. Results indicate that using moist SVs instead of dry SVs has a stronger impact on precipitation than on dynamical fields. Forecast skill for precipitation is greatly influenced by the dominant synoptic weather systems. For stratiform precipitation caused by strong baroclinic systems, the forecast skill is improved in the moist SV experiments relative to the dry SV experiments. For convective precipitation rates in the range 15-50 mm (24 h)-1 produced by weak synoptic baroclinic systems, all experiments exhibit noticeably poorer forecast skills. Skill improvements due to the Interactions between Soil, Biosphere, and Atmosphere (ISBA) surface scheme and stochastic perturbations are also observed. © 2008 American Meteorological Society."
"7405728922;7202180152;6701497749;36932594300;6603262263;6701562113;55476830600;55717074000;","Aerosol indirect effect on the grid-scale clouds in the two-way coupled WRF-CMAQ: Model description, development, evaluation and regional analysis",2014,"10.5194/acp-14-11247-2014","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84908410171&doi=10.5194%2facp-14-11247-2014&partnerID=40&md5=c0f357a4b6dcf716ac04683bc90dbae3","This study implemented first, second and glaciation aerosol indirect effects (AIE) on resolved clouds in the two-way coupled Weather Research and Forecasting Community Multiscale Air Quality (WRF-CMAQ) modeling system by including parameterizations for both cloud drop and ice number concentrations on the basis of CMAQpredicted aerosol distributions and WRF meteorological conditions. The performance of the newly developed WRF- CMAQ model, with alternate Community Atmospheric Model (CAM) and Rapid Radiative Transfer Model for GCMs (RRTMG) radiation schemes, was evaluated with observations from the Clouds and the See http://ceres.larc. nasa.gov/. Earth's Radiant Energy System (CERES) satellite and surface monitoring networks (AQS, IMPROVE, CASTNET, STN, and PRISM) over the continental US (CONUS) (12 km resolution) and eastern Texas (4 km resolution) during August and September of 2006. The results at the Air Quality System (AQS) surface sites show that in August, the normalized mean bias (NMB) values for PM2.5 over the eastern US (EUS) and the western US (WUS) are 5.3% (-0.1 %) and 0.4% (-5.2 %) for WRF-CMAQ/CAM (WRF-CMAQ/RRTMG), respectively. The evaluation of PM2.5 chemical composition reveals that in August, WRF-CMAQ/CAM (WRF-CMAQ/RRTMG) consistently underestimated the observed SO2-4 by -23.0% (-27.7 %), -12.5% (-18.9 %) and -7.9% (-14.8 %) over the EUS at the Clean Air Status Trends Network (CASTNET), Interagency Monitoring of Protected Visual Environments (IMPROVE) and Speciated Trends Network (STN) sites, respectively. Both configurations (WRF-CMAQ/CAM, WRF-CMAQ/RRTMG) overestimated the observed mean organic carbon (OC), elemental carbon (EC) and and total carbon (TC) concentrations over the EUS in August at the IMPROVE sites. Both configurations generally underestimated the cloud field (shortwave cloud forcing, SWCF) over the CONUS in August due to the fact that the AIE on the subgrid convective clouds was not considered when the model simulations were run at the 12 km resolution. This is in agreement with the fact that both configurations captured SWCF and longwave cloud forcing (LWCF) very well for the 4 km simulation over eastern Texas, when all clouds were resolved by the finer resolution domain. The simulations of WRF-CMAQ/CAM and WRF-CMAQ/RRTMG show dramatic improvements for SWCF, LWCF, cloud optical depth (COD), cloud fractions and precipitation over the ocean relative to those of WRF default cases in August. The model performance in September is similar to that in August, except for a greater overestimation of PM2.5 due to the overestimations of SO2-4 , NH+4 , NO-3 , and TC over the EUS, less underestimation of clouds (SWCF) over the land areas due to the lower SWCF values, and fewer convective clouds in September. This work shows that inclusion of indirect aerosol effect treatments in WRF-CMAQ represents a significant advancement and milestone in air quality modeling and the development of integrated emissions control strategies for air quality management and climate change mitigation. © 2014 Author(s)."
"55709068100;56014821400;52464842700;55994328200;","Object-based approach to national land cover mapping using HJ satellite imagery",2014,"10.1117/1.JRS.8.083686","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84897775628&doi=10.1117%2f1.JRS.8.083686&partnerID=40&md5=a299d7a245ed807b25f692e31abaae27","To meet the carbon storage estimate in ecosystems for a national carbon strategy, we introduce a consistent database of China land cover. The Chinese Huan Jing (HJ) satellite is proven efficient in the cloud-free acquisition of seasonal image series in a monsoon region and in vegetation identification for mesoscale land cover mapping. Thirty-eight classes of level II land cover are generated based on the Land Cover Classification System of the United Nations Food and Agriculture Organization that follows a standard and quantitative definition. Twenty-four layers of derivative spectral, environmental, and spatial features compose the classification database. Object-based approach characterizing additional nonspectral features is conducted through mapping, and multiscale segmentations are applied on object boundary match to target real-world conditions. This method sufficiently employs spatial information, in addition to spectral characteristics, to improve classification accuracy. The algorithm of hierarchical classification is employed to follow step-by-step procedures that effectively control classification quality. This algorithm divides the dual structures of universal and local trees. Consistent universal trees suitable to most regions are performed first, followed by local trees that depend on specific features of nine climate stratifications. The independent validation indicates the overall accuracy reaches 86%. © 2014 Society of Photo-Optical Instrumentation Engineers."
"7006095466;","The Multiscale Organization of Moist Convection and the Intersection of Weather and Climate",2013,"10.1029/2008GM000838","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84951267523&doi=10.1029%2f2008GM000838&partnerID=40&md5=1135d7bc724e4429bce4f6ba0cbad04b","Moist convection organizes into cloud systems of various sizes and kinds, a process with a dynamical basis and upscale connotations. Although organized precipitation systems have been extensively observed, numerically simulated, and dynamically modeled, our knowledge of their effects on weather and climate is far from complete. Convective organization is absent de facto from contemporary climate models because the salient dynamics are not represented by parameterizations and the model resolution is insufficient to represent them explicitly. Highresolution weather prediction models, fine-resolution cloud system models, and dynamical models address moist convective organization explicitly. As a key element in the seamless prediction of weather and climate on timescales up to seasonal, organized convection is the focus of the Year of Tropical Convection, an international collaborative project coordinated by the World Meteorological Organisation. This paper reviews the scientific basis of convective organization and progress toward comprehending its large-scale effects and representing them in global models. © 2010 by the American Geophysical Union. All rights reserved."
"48361810500;57199060381;56003156300;46261510000;8526596200;36520959600;7102197206;7003352529;7202505831;","A Comparison of two open source LiDAR surface classification algorithms",2011,"10.3390/rs3030638","https://www.scopus.com/inward/record.uri?eid=2-s2.0-80052018300&doi=10.3390%2frs3030638&partnerID=40&md5=f6150047915d1dda7cbf467932a4cda8","With the progression of LiDAR (Light Detection and Ranging) towards a mainstream resource management tool, it has become necessary to understand how best to process and analyze the data. While most ground surface identification algorithms remain proprietary and have high purchase costs; a few are openly available, free to use, and are supported by published results. Two of the latter are the multiscale curvature classification and the Boise Center Aerospace Laboratory LiDAR (BCAL) algorithms. This study investigated the accuracy of these two algorithms (and a combination of the two) to create a digital terrain model from a raw LiDAR point cloud in a semi-arid landscape. Accuracy of each algorithm was assessed via comparison with ≤7,000 high precision survey points stratified across six different cover types. The overall performance of both algorithms differed by only 2%; however, within specific cover types significant differences were observed in accuracy. The results highlight the accuracy of both algorithms across a variety of vegetation types, and ultimately suggest specific scenarios where one approach may outperform the other. Each algorithm produced similar results except in the ceanothus and conifer cover types where BCAL produced lower errors. © 2011 by the authors."
"7101959253;7005626683;","An analysis of cloud cover in multiscale modeling framework global climate model simulations using 4 and 1 km horizontal grids",2010,"10.1029/2009JD013423","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77956203733&doi=10.1029%2f2009JD013423&partnerID=40&md5=82a97b14b037f14e39631faf580b9c5f","Over the past few years, a new type of global climate model (GCM) has emerged in which a two-dimensional or small three-dimensional cloud resolving model is embedded into each grid cell of a GCM. This approach is frequently called the multiscale modeling framework (MMF) but is also known as a cloud-resolving convection parameterization or a superparameterization. In this article, we compare joint histograms of cloud top height and optical depth from the MMF with those being produced by the International Satellite Cloud Climatology Project (ISCCP) and from the Multiangle Imaging Spectroradiometer (MISR). While the form of the ISCCP and MISR data sets is conceptually similar, the satellite sensors and the algorithms differ, with the result that the joint histograms can differ quite significantly even when viewing exactly the same clouds. The analysis takes advantages of the strengths of each data set, as well as the differences in these data (which, for example, allow one to characterize the amount of some multilayer clouds). MMF simulation runs with three different resolutions are analyzed. One simulation is run using a 4 km horizontal grid with 26 vertical levels (on a stretched grid), a second simulation is run with a 1 km horizontal grid and the same 26 vertical levels, and a third simulation is run with a 1 km horizontal grid and 52 vertical levels. The analysis shows that the MMF reproduces the broad pattern of tropical convergence zones, subtropical belts, and midlatitude storm tracks as observed by ISCCP and MISR. However, the model has several significant shortcomings. Perhaps most seriously, it significantly underpredicts the amount of low-level cloud in most regions. The simulation with a 1 km horizontal grid and 52 vertical layers is found to improve modestly several aspect of the MMF low-level cloud cover. The model output is obtained using ISCCP and MISR instrument simulators and the role of horizontal resolution in the instrument simulators is examined. Copyright 2010 by the American Geophysical Union."
"57217561201;6602378790;6603262263;6701497749;","Sensitivity of the community multiscale air quality (CMAQ) model v4.7 results for the eastern united states to MM5 and WRF meteorological drivers",2010,"10.5194/gmd-3-169-2010","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77953962060&doi=10.5194%2fgmd-3-169-2010&partnerID=40&md5=00aaf2158ecf38e01f79e1f6b0e77fe2","This paper presents a comparison of the operational performances of two Community Multiscale Air Quality (CMAQ) model v4.7 simulations that utilize input data from the 5th-generation Mesoscale Model (MM5) and the Weather Research and Forecasting (WRF) meteorological models. Two sets of CMAQ model simulations were performed for January and August 2006. One set utilized MM5 meteorology (MM5-CMAQ) and the other utilized WRF meteorology (WRF-CMAQ), while all other model inputs and options were kept the same. For January, predicted ozone (O3) mixing ratios were higher in the Southeast and lower Mid-west regions in the WRF-CMAQ simulation, resulting in slightly higher bias and error as compared to the MM5-CMAQ simulations. The higher predicted O 3 mixing ratios are attributed to less dry deposition of O 3 in the WRF-CMAQ simulation due to differences in the calculation of the vegetation fraction between the MM5 and WRF models. The WRF-CMAQ results showed better performance for particulate sulfate (SO42-), similar performance for nitrate (NO3-), and slightly worse performance for nitric acid (HNO3), total carbon (TC) and total fine particulate (PM2.5) mass than the corresponding MM5-CMAQ results. For August, predictions of O3 were notably higher in the WRF-CMAQ simulation, particularly in the southern United States, resulting in increased model bias. Concentrations of predicted particulate SO 42- were lower in the region surrounding the Ohio Valley and higher along the Gulf of Mexico in the WRF-CMAQ simulation, contributing to poorer model performance. The primary causes of the differences in the MM5-CMAQ and WRF-CMAQ simulations appear to be due to differences in the calculation of wind speed, planetary boundary layer height, cloud cover and the friction velocity (u*) in the MM5 and WRF model simulations, while differences in the calculation of vegetation fraction and several other parameters result in smaller differences in the predicted CMAQ model concentrations. The performance for SO42-, NO3- and NH 4+ wet deposition was similar for both simulations for January and August."
"6701358470;7202163945;7201771183;7202612588;57190613121;6603699729;36801353600;","Assessment of land-surface energy budgets from regional and global models",1999,"10.1029/1999JD900128","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033609585&doi=10.1029%2f1999JD900128&partnerID=40&md5=a040d60864f4e9d21c4eeaf7462c60a4","The surface energy budgets estimated from the 0- to 12-hour forecasts of three operational model suites and the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) Reanalysis are analyzed at local to continental scales. The models are (1) the Eta model, (2) the Mesoscale Analysis and Prediction System (MAPS), and (3) the Global Environmental Multiscale (GEM) model. The first two are regional, while the third one is global with a variable grid with a resolution over North America that is equivalent to that of the regional models. This assessment of one summer month (August 1997) and one winter month (January 1998) has the purpose of estimating the reliability of the surface energy budgets within the context of the Global Energy and Water Cycle Experiment (GEWEX) Continental-Scale International Project (GCIP) goals. Satellite estimates were used to evaluate the downward short wave radiation at the surface, while measurements from the southern Great Plains region were used to evaluate the model computed surface energy budget estimates. The results show that the surface short wave radiation biases of the models are widespread and of the order of 25-50 W m-2 and averaging over larger areas does not help reduce the differences. These biases are compensated by the other long and short wave radiation terms so that the resulting errors in the net radiation are smaller. During August 1997, continental east-west gradients of latent heat flux and Bowen ratio were surprisingly dissimilar among models. Still, the Bowen ratio estimated from the Eta and GEM models was close to observations over the southern Great Plains region, while both the Reanalysis and MAPS had ratios that at least doubled the observed ones. In the case of MAPS a revised latent heat flux formulation was introduced in fall 1997, and, subsequently, for January 1998, estimates were closer to the other models' estimates. However, during January 1998 all models had difficulties reproducing the Bowen ratios from observations. Further, daily time series showed that models' estimates also tended to miss the amplitude of the day-to-day variability. It is conceivable that this may be the result of difficulties in parameterizing the total cloud cover, and, particularly, attenuation by clouds may still be insufficient. Copyright 1999 by the American Geophysical Union."
"23019837200;6507458732;","Multiscale computation of solar radiation for predictive vegetation modelling",2007,"10.1051/forest:2007072","https://www.scopus.com/inward/record.uri?eid=2-s2.0-36549074499&doi=10.1051%2fforest%3a2007072&partnerID=40&md5=21120c0900819277dfd2e5cee40d5ea3","The recent development of large environmental databases allow the analysis of the ecological behaviour of species or communities over large territories. Solar radiation is a fundamental component of ecological processes, but is poorly used at this scale due to the lack of available data. Here we present a GIS program allowing to calculate solar radiation as well locally as at large scale, taking into account both topographical (slope, aspect, altitude, shadowing) and global (cloudiness and latitude) parameters. This model was applied to the whole of France (540 000 km2 for each month of the year, using only a 50-m digital elevation model (DEM), latitude values and cloudiness data. Solar radiation measured from 88 meteorological stations used for validation indicated a R2 of 0.78 between measured and predicted annual radiation with better predictions for winter than for summer. Radiation values increase with altitude, and with slope for southern exposure, excepted in summer. They decrease with latitude, nebulosity, and slope for north, east, and west exposures. The effect of cloudiness is important, and reduces radiation by around 20% in winter and 10% in summer. Models of plant distribution were calculated for Abies alba, Acer pseudoplatanus, and Quercus pubescens, for France. The use of solar radiation improved modelling for the three species models directly or through the water balance variable. We conclude that models which incorporates both topographical and global variability of solar radiation can improve efficiency of large-scale models of plant distribution. © INRA, EDP Sciences, 2007."
"6603109490;7202343918;36643323800;7102598804;7403483250;57211327514;6504114040;55393913800;","Evaluation of the Operational Multiscale Environment Model with Grid Adaptivity against the European Tracer Experiment",2001,"10.1175/1520-0450(2001)040<1541:EOTOME>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0035443450&doi=10.1175%2f1520-0450%282001%29040%3c1541%3aEOTOME%3e2.0.CO%3b2&partnerID=40&md5=5b193eb85dbe612b3023f6ee942c3a79","The Operational Multiscale Environment Model with Grid Adaptivity (OMEGA) is a multiscale nonhydrostatic atmospheric simulation system based on an adaptive unstructured grid. The basic philosophy behind the OMEGA development has been the creation of an operational tool for real-time aerosol and gas hazard prediction. The model development has been guided by two basic design considerations in order to meet the operational requirements: 1) the application of an unstructured dynamically adaptive mesh numerical technique to atmospheric simulation, and 2) the use of embedded atmospheric dispersion algorithms. An important step in proving the utility and accuracy of OMEGA is the full-scale testing of the model using simulations of real-world atmospheric events and qualitative as well as quantitative comparisons of the model results with observations. The main objective of this paper is to provide a comprehensive evaluation of OMEGA against a major dispersion experiment in operational mode. Therefore, OMEGA was run to create a 72-h forecast for the first release period (23-26 October 1994) of the European Tracer Experiment (ETEX). The predicted meteorological and dispersion fields were then evaluated against both the atmospheric observations and the ETEX dispersion measurements up to 60 h after the start of the release. In general, the evaluation showed that the OMEGA dispersion results were in good agreement in the position, shape, and extent of the tracer cloud. However, the model prediction indicated that there was a limited spreading of the predictions around the measurements with a small tendency to under-estimate the concentration values."
"7202244409;57196027125;55531715700;57193551962;","Cloud detection in remote sensing images based on multiscale features-convolutional neural network",2019,"10.1109/TGRS.2018.2889677","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85066607253&doi=10.1109%2fTGRS.2018.2889677&partnerID=40&md5=9eed7183d1e3a92cddcd3c8f7932eb50","Cloud detection in remote sensing images is a challenging but significant task. Due to the variety and complexity of underlying surfaces, most of the current cloud detection methods have difficulty in detecting thin cloud regions. In fact, it is quite meaningful to distinguish thin clouds from thick clouds, especially in cloud removal and target detection tasks. Therefore, we propose a method based on multiscale features-convolutional neural network (MF-CNN) to detect thin cloud, thick cloud, and noncloud pixels of remote sensing images simultaneously. Landsat 8 satellite imagery with various levels of cloud coverage is used to demonstrate the effectiveness of our proposed MF-CNN model. We first stack visible, near-infrared, short-wave, cirrus, and thermal infrared bands of Landsat 8 imagery to obtain the combined spectral information. The MF-CNN model is then used to learn the multiscale global features of input images. The high-level semantic information obtained in the process of feature learning is integrated with low-level spatial information to classify the imagery into thick, thin and noncloud regions. The performance of our proposed model is compared to that of various commonly used cloud detection methods in both qualitative and quantitative aspects. Compared to other cloud detection methods, the experimental results show that our proposed method has a better performance not only in thick and thin clouds but also in the entire cloud regions. © 1980-2012 IEEE."
"7202317354;56676251800;14034439700;57193088012;57193082910;","Application of UAV photogrammetry for the multi-temporal estimation of surface extent and volumetric excavation in the Sa Pigada Bianca open-pit mine, Sardinia, Italy",2017,"10.1007/s12665-017-6409-z","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85010680143&doi=10.1007%2fs12665-017-6409-z&partnerID=40&md5=cbd47fefc750362a393eb646c5609d58","In open-pit mines, monitoring of topographic and volumetric changes through time is found to be of great importance to support excavation stages and to plan rehabilitation strategies. In this work, we describe a geomatic approach to assess changes in surface mine extent and to quantify excavated volume in the Sa Pigada open-pit mine, Sardinia, Italy. We performed two drone-based photogrammetric surveys in 2013 and 2015, and by means of the Structure from Motion (SfM) technique, we obtained related 3D dense point clouds and digital orthophotos. Images were georeferenced thanks to a series of ground control points surveyed with geodetic GPS. Distances between the two clouds were estimated with the recent Multiscale Model to Model Cloud Comparison (M3C2) plug-in included in the CloudCompare open-source software. Starting from cloud-to-cloud distances, we calculated the excavated volume of mineral resources between the two surveys. Results of the M3C2 comparison supported the analysis of the two orthophotos, through which accurate limits of the 2013 and 2015 active mine areas, rehabilitated area and temporary dumps were identified and drawn in a digital map. Results obtained in this study suggest that the applied geomatic techniques are suitable for performing accurate change detection analysis in open-pit environments and represent a valid support for scientists and technicians allowing to monitor with high spatial and temporal resolutions. This approach can be also considered a valid tool to reduce environmental impact from mining. © 2017, Springer-Verlag Berlin Heidelberg."
"7202772927;7401701196;11839267100;55718206700;7403577184;7102718675;6701718281;7101801476;6701845806;36864279000;7203062717;57217518784;7006957668;7401559815;55823994500;","The Goddard Cumulus Ensemble model (GCE): Improvements and applications for studying precipitation processes",2014,"10.1016/j.atmosres.2014.03.005","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84897415726&doi=10.1016%2fj.atmosres.2014.03.005&partnerID=40&md5=9c2f5abe7e80639c95b72ea52218bcd9","Convection is the primary transport process in the Earth's atmosphere. About two-thirds of the Earth's rainfall and severe floods derive from convection. In addition, two-thirds of the global rain falls in the tropics, while the associated latent heat release accounts for three-fourths of the total heat energy for the Earth's atmosphere. Cloud-resolving models (CRMs) have been used to improve our understanding of cloud and precipitation processes and phenomena from micro-scale to cloud-scale and mesoscale as well as their interactions with radiation and surface processes. CRMs use sophisticated and realistic representations of cloud microphysical processes and can reasonably well resolve the time evolution, structure, and life cycles of clouds and cloud systems. CRMs also allow for explicit interaction between clouds, outgoing longwave (cooling) and incoming solar (heating) radiation, and ocean and land surface processes. Observations are required to initialize CRMs and to validate their results. The Goddard Cumulus Ensemble model (GCE) has been developed and improved at NASA/Goddard Space Flight Center over the past three decades. It is a multi-dimensional non-hydrostatic CRM that can simulate clouds and cloud systems in different environments. Early improvements and testing were presented in Tao and Simpson (1993) and Tao et al. (2003a). A review on the application of the GCE to the understanding of precipitation processes can be found in Simpson and Tao (1993) and Tao (2003). In this paper, recent model improvements (microphysics, radiation and land surface processes) are described along with their impact and performance on cloud and precipitation events in different geographic locations via comparisons with observations. In addition, recent advanced applications of the GCE are presented that include understanding the physical processes responsible for diurnal variation, examining the impact of aerosols (cloud condensation nuclei or CCN and ice nuclei or IN) on precipitation processes, utilizing a satellite simulator to improve the microphysics, providing better simulations for satellite-derived latent heating retrieval, and coupling with a general circulation model to improve the representation of precipitation processes. Future research is also discussed. © 2014."
"7003803916;8565323700;7006711251;38461378900;7005794379;7004372407;15823290900;55398698300;7201926991;","Multiscale aspects of convective systems associated with an intraseasonal oscillation over the Indonesian Maritime Continent",2006,"10.1175/MWR3152.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33646447061&doi=10.1175%2fMWR3152.1&partnerID=40&md5=015a67d13dbba60658301b9ed3dbe14f","Multiscale aspects of convective systems over the Indonesian Maritime Continent in the convectively active phase of an intraseasonal oscillation (ISO) during November 2002 are studied using Geostationary Meteorological Satellite infrared data and ground-based observational data from X-band rain radar, equatorial atmosphere radar, L-band boundary layer radar, and upper-air soundings at Koto Tabang (KT; 0.20°S, 100.32°E; 865 m above mean sea level), West Sumatera, Indonesia. In the analysis period, four super cloud clusters (SCCs; horizontal scale of 2000-4000 km), associated with an ISO, are seen to propagate eastward from the eastern Indian Ocean to the Indonesian Maritime Continent. The SCCs are recognized as envelopes of convection, composed of meso-α-scale cloud clusters (MαCCs; horizontal scale of 500-1000 km) propagating westward. When SCCs reach the Indonesian Maritime Continent, the envelopes disappear but MαCCs are clearly observed. Over Sumatera, the evolution and structure of a distinct MαCC is closely related to the organization of localized cloud systems with a diurnal cycle. The cloud systems are characterized by westward-propagating meso-β-scale cloud clusters (MβCCs; horizontal scale of ∼100 km) developed in eastern Sumatera, and an orographic cloud system formed over a mountain range in western Sumatera. Ground-based observations further revealed the internal structure of the orographic cloud system around KT. A meso-β-scale convective precipitation system with eastward propagation (E-MβCP; horizontal scale of ∼40 km) is found with the formation of the orographic cloud system. This is associated with a low-level wind change from easterly to westerly, considered to be local circulation over the mountain range. The E-MβCP also indicates a multicell structure composed of several meso-γ-scale convective precipitation systems (horizontal scale of <10 km) with multiple evolution stages (formation, development, and dissipation). © 2006 American Meteorological Society."
"7401945370;7201504886;36646089600;6701346974;57208455668;8687063000;54879515900;","Global Cloud-Resolving Models",2019,"10.1007/s40641-019-00131-0","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85066108278&doi=10.1007%2fs40641-019-00131-0&partnerID=40&md5=293f1c4b2b8ce22f4552b3c953d69036","Purpose of Review: Global cloud-resolving models (GCRMs) are a new type of atmospheric model which resolve nonhydrostatic accelerations globally with kilometer-scale resolution. This review explains what distinguishes GCRMs from other types of models, the problems they solve, and the questions their more commonplace use is raising. Recent Findings: GCRMs require high-resolution discretization over the sphere but can differ in many other respects. They are beginning to be used as a main stream research tool. The first GCRM intercomparison studies are being coordinated, raising new questions as to how best to exploit their advantages. Summary: GCRMs are designed to resolve the multiscale nature of moist convection in the global dynamics context, without using cumulus parameterization. Clouds are simulated with cloud microphysical schemes in ways more comparable to observations. Because they do not suffer from ambiguity arising from cumulus parameterization, as computational resources increase, GCRMs are the promise of a new generation of global weather and climate simulations. © 2019, The Author(s)."
"50660941400;55486059500;35115110600;15840922100;50662168500;55376826900;","Multiscale grid method for detection and reconstruction of building roofs from airborne LiDAR data",2014,"10.1109/JSTARS.2014.2306003","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84920126848&doi=10.1109%2fJSTARS.2014.2306003&partnerID=40&md5=0c0ec801515cf83014897eee2bfa0100","This study proposes a multiscale grid method to detect and reconstruct building roofs from airborne LiDAR data. The method interpolates unorganized LiDAR point cloud into two sets of grids with different spatial scales. In the large-scale grid, building seed regions are obtained, including detection of initial building seed regions and refinement of building seed regions. In the small-scale grid, to detect the detailed features of building roofs with complicated top structures, a high-resolution depth image is generated by a new iterative morphological interpolation using gradually increasing scales, and then segmented by using a full λ-schedule algorithm. Based on the building seed regions, detailed roof features are detected for each building and 3-D building roof models are then reconstructed according to the elevation of these features. Experiments are analyzed from several aspects: the correctness and completeness, the elevation accuracy of building roof models, and the influence of elevation to 3-D roof reconstruction. The experimental results demonstrate promising correctness, completeness, and elevation accuracy, with a satisfactory 3-D building roof models. The strategy of hierarchical spatial scale (from large scale to small scale) obtains the complementary advantage between technical applicability in a large urban environment and high quality in 3-D reconstruction of building roofs with fine details. © 2014 IEEE."
"6602801069;","Modeling the ETEX plume dispersion with the Canadian emergency response model",1998,"10.1016/S1352-2310(98)00182-4","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032403144&doi=10.1016%2fS1352-2310%2898%2900182-4&partnerID=40&md5=51921ef7c77f3d382d635556f088c508","The CANadian Emergency Response Model (CANERM) was used to simulate the dispersion resulting from the ETEX release of 23 October 1994. Dispersion simulations were done using three different data sets as meteorological input: the ECMWF/ETEX Data Set, data from the CMC Global Data Assimilation System, and results from a diagnostic execution of the Global Environmental Multiscale (GEM) model. Comparisons of the dispersion simulations are made with observed surface concentration data provided by the Joint Research Centre (JRC) of the European Commission. It is found that CANERM can simulate fairly well the main features of the cloud dispersion. The spatial and temporal evolution of the simulated cloud appear quite plausible, but a tendency to overestimate surface concentrations is apparent. The simulations provide a credible explanation for the two peaks observed at station NL01; the first peak appears to be associated with the passage of the head portion of the plume, while the second seems to be associated with the tail part. Verification scores indicate that the simulations using the ECMWF/ETEX data set and CMC global data are of equivalent quality. However, the simulations obtained using the GEM diagnostic fields are significantly better.The CANadian Emergency Response Model (CANERM) was used to simulate the dispersion resulting from the ETEX release of 23 October 1994. Dispersion simulations were done using three different data sets as meteorological input: the ECMWF/ETEX Data Set, data from the CMC Global Data Assimilation System, and results from a diagnostic execution of the Global Environmental Multiscale (GEM) model. Comparisons of the dispersion simulations are made with observed surface concentration data provided by the Joint Research Centre (JRC) of the European Commission. It is found that CANERM can simulate fairly well the main features of the cloud dispersion. The spatial and temporal evolution of the simulated cloud appear quite plausible, but a tendency to overestimate surface concentrations is apparent. The simulations provide a credible explanation for the two peaks observed at station NL01; the first peak appears to be associated with the passage of the head portion of the plume, while the second seems to be associated with the tail part. Verification scores indicate that the simulations using the ECMWF/ETEX data set and CMC global data are of equivalent quality. However, the simulations obtained using the GEM diagnostic fields are significantly better."
"55578187900;55578807789;57200498359;15846506300;","An efficient global energy optimization approach for robust 3D plane segmentation of point clouds",2018,"10.1016/j.isprsjprs.2018.01.013","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85041388663&doi=10.1016%2fj.isprsjprs.2018.01.013&partnerID=40&md5=3a51448902248e5ca7e81c99452a6f95","Automatic 3D plane segmentation is necessary for many applications including point cloud registration, building information model (BIM) reconstruction, simultaneous localization and mapping (SLAM), and point cloud compression. However, most of the existing 3D plane segmentation methods still suffer from low precision and recall, and inaccurate and incomplete boundaries, especially for low-quality point clouds collected by RGB-D sensors. To overcome these challenges, this paper formulates the plane segmentation problem as a global energy optimization because it is robust to high levels of noise and clutter. First, the proposed method divides the raw point cloud into multiscale supervoxels, and considers planar supervoxels and individual points corresponding to nonplanar supervoxels as basic units. Then, an efficient hybrid region growing algorithm is utilized to generate initial plane set by incrementally merging adjacent basic units with similar features. Next, the initial plane set is further enriched and refined in a mutually reinforcing manner under the framework of global energy optimization. Finally, the performances of the proposed method are evaluated with respect to six metrics (i.e., plane precision, plane recall, under-segmentation rate, over-segmentation rate, boundary precision, and boundary recall) on two benchmark datasets. Comprehensive experiments demonstrate that the proposed method obtained good performances both in high-quality TLS point clouds (i.e., SEMANTIC3D.NET dataset) and low-quality RGB-D point clouds (i.e., S3DIS dataset) with six metrics of (94.2%, 95.1%, 2.9%, 3.8%, 93.6%, 94.1%) and (90.4%, 91.4%, 8.2%, 7.6%, 90.8%, 91.7%) respectively. © 2018 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS)"
"7101661890;7006095466;","Stratospheric gravity waves generated by multiscale tropical convection",2008,"10.1175/2007JAS2601.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-51749106111&doi=10.1175%2f2007JAS2601.1&partnerID=40&md5=e7b1ad6957129801044e5ae423f67b66","The generation of gravity waves by multiscale cloud systems evolving in an initially motionless and thermodynamically uniform environment is explored using a two-dimensional cloud-system-resolving model. The simulated convection has similar depth and intensity to observed tropical oceanic systems. The convection self-organizes into preferred horizontal and temporal scales involving weakly organized propagating cloud clusters. The multiscale systems generate a broad spectrum of gravity waves with horizontal scales that range from the cloud-system scale up to the cloud-cluster scale. The gravity waves with the largest horizontal scale play an important role in modifying layered tropospheric inflow and outflow to the cloud systems, which in turn influence the multiscale convective organization. Slower-moving short-scale gravity waves make the strongest individual contribution to the vertical flux of horizontal momentum and cause a robust peak in the momentum flux spectrum that corresponds to the lifetime and spatial scale of the individual cloud systems. © 2008 American Meteorological Society."
"55481711800;16241933300;6507864329;6701611096;7005054220;6603343577;7101638253;","Higher surface ozone concentrations over the Chesapeake Bay than over the adjacent land: Observations and models from the DISCOVER-AQ and CBODAQ campaigns",2014,"10.1016/j.atmosenv.2013.11.008","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84889648093&doi=10.1016%2fj.atmosenv.2013.11.008&partnerID=40&md5=8696fd1a136ff961597fc7ae3a2fc61f","Air quality models, such as the Community Multiscale Air Quality (CMAQ) model, indicate decidedly higher ozone near the surface of large interior water bodies, such as the Great Lakes and Chesapeake Bay. In order to test the validity of the model output, we performed surface measurements of ozone (O3) and total reactive nitrogen (NOy) on the 26-m Delaware II NOAA Small Research Vessel experimental (SRVx), deployed in the Chesapeake Bay for 10 daytime cruises in July 2011 as part of NASA's GEO-CAPE CBODAQ oceanographic field campaign in conjunction with NASA's DISCOVER-AQ air quality field campaign. During this 10-day period, the EPA O3 regulatory standard of 75ppbv averaged over an 8-hperiod was exceeded four times over water while ground stations in the area only exceeded the standard at most twice. This suggests that on days when the Baltimore/Washington region is in compliance with the EPA standard, air quality over the Chesapeake Bay might exceed the EPA standard. Ozone observations over the bay during the afternoon were consistently 10-20% higher than the closest upwind ground sites during the 10-day campaign; this pattern persisted during good and poor air quality days. A lower boundary layer, reduced cloud cover, slower dry deposition rates, and other lesser mechanisms, contribute to the local maximum of ozone over the Chesapeake Bay. Observations from this campaign were compared to a CMAQ simulation at 1.33km resolution. The model is able to predict the regional maximum of ozone over the Chesapeake Bay accurately, but NOy concentrations are significantly overestimated. Explanations for the overestimation of NOy in the model simulations are also explored. © 2013 Elsevier Ltd."
"26434854300;8576112000;7006425629;7004091561;6603497236;","Organosulfates in cloud water above the Ozarks' isoprene source region",2013,"10.1016/j.atmosenv.2013.05.011","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84878733496&doi=10.1016%2fj.atmosenv.2013.05.011&partnerID=40&md5=0f4503ed5b19c8c4d150119f3eda23a2","Secondary organic aerosol formation via aqueous processing, particularly from the oxidation of biogenic volatile organic compounds, is hypothesized to contribute significantly to the global aerosol burden. In this study, electrospray ionization coupled with mass spectrometry (ESI-MS) was utilized to detect organosulfates and oligomers in cloud water collected in July above the Missouri Ozarks, an environment significantly influenced by isoprene oxidation. Community Multiscale Air Quality (CMAQ) modeling suggested that the aerosol at cloud height was characterized by high water, sulfate, and biogenic secondary organic aerosol content, conducive to aqueous-phase processing and organosulfate formation. CMAQ modeling also suggested the presence of gas-phase organic peroxides and nitrates, which can partition into the particle-phase and form organosulfates. Several potential organosulfates from isoprene, monoterpene, and sesquiterpene oxidation were detected in the cloud water. In particular, the ubiquitous organosulfate C5H12O7S (detected by ESI-MS at m/z -215), derived from isoprene epoxydiols, was detected. These results highlight the role of aqueous-phase reactions in biogenic SOA formation and cloud processes in isoprene oxidation-influenced regions. © 2013 Elsevier Ltd."
"8977001000;7403282069;","Improved low-cloud simulation from a multiscale modeling framework with a third-order turbulence closure in its cloud-resolving model component",2011,"10.1029/2010JD015362","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79960476438&doi=10.1029%2f2010JD015362&partnerID=40&md5=ddadfffb3929d7b5304581ef7b65fe8e","In the original multiscale modeling framework (MMF), the Community Atmosphere Model (CAM3.5) is used as the host general circulation model (GCM), and the System for Atmospheric Modeling model with a first-order turbulence closure is used as the cloud resolving model (CRM) for representing cloud physical processes in each grid column of the GCM. This study introduces an upgrade of the MMF in which the first-order turbulence closure scheme is replaced by an advanced third-order turbulence closure in its CRM component. The results are compared between the upgraded and original MMFs, CAM3.5, and observations. The global distributions of low-level cloud amounts in the subtropics in the upgraded MMF show substantial improvement relative to the original MMF when both are compared with observations. The improved simulation of low-level clouds is attributed not only to the representation of subgrid-scale condensation in the embedded CRM but also is closely related to the increased surface sensible and latent heat fluxes, the increased lower tropospheric stability (LTS), and stronger longwave radiative cooling. Both MMF simulations show close agreement in the vertical structures of cloud amount and liquid water content of midlatitude storm-track clouds and subtropical low-level clouds, compared with observations, with the upgraded MMF being better at simulating the low-level cumulus regime. Since the upgraded MMF produces more subtropical low-level clouds and does not produce an excessive amount of optically thick high-level clouds in either the tropics or midlatitudes as the original MMF does, the global mean albedo decreases. The positive bias in albedo and longwave cloud radiative forcing (CRF) and negative bias in shortwave CRF are reduced in the tropical convective regions. Copyright 2011 by the American Geophysical Union."
"6602999057;","Tropical-extratropical interactions associated with an Atlantic tropical plume and subtropical jet streak",2005,"10.1175/MWR2999.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-27144481657&doi=10.1175%2fMWR2999.1&partnerID=40&md5=89ba8a3d6ed2bd6990c741509aadd191","Tropical plumes (TPs) are elongated bands of upper- and midlevel clouds stretching from the Tropics poleward and eastward into the subtropics, typically accompanied by a subtropical jet (STJ) streak and a trough on their poleward side. This study uses ECMWF analyses and high-resolution University of Wisconsin-Nonhydrostatic Modeling System trajectories to analyze the multiscale complex tropical extratropical interactions involved in the genesis of a pronounced TP and STJ over the NH Atlantic Ocean in late March 2002 that was associated with extreme precipitation in and northwest Africa. Previous concepts for TP genesis from the literature are discussed in the light of this case study. Analysis of t he upper-level flow prior to the TP formation shows a northeastward propagation and a continuous acceleration of the STJ over the Atlantic Ocean equatorward of a positively tilted upper-level trough to the west of northwest Africa. Both dynamic and advective processes contribute to the generation of the accompanying cloud band. The northern portion of the TP consists of parcels that exit a strong STJ streak over North America, enter the deep Tropics over South America, and then accelerate into the Atlantic STJ, accompanied by strong cross-jet ageostrophic motions, rising, and cloud formation. The southern portion is formed by parcels originating in the divergent outflow from strong near-equatorial convection accompanying the TP genesis. A local increase in the Hadley overturning is found over the tropical Atlantic and east Pacific/South America and appears to be related to low inertial stability at the outflow level and to low-level trade surges associated with the cold advection, sinking, and lower-level divergence underneath two strong upper-level convergence centers in the eastern portions of both a subtropical ridge over North America and an extratropical ridge over the North Atlantic Ocean. Evidence is presented that the convective response lags the trade surge by several days. © 2005 American Meteorological Society."
"57195504497;57195503168;55923803000;56683735000;57195504110;55726588900;","Distinguishing Cloud and Snow in Satellite Images via Deep Convolutional Network",2017,"10.1109/LGRS.2017.2735801","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85028506011&doi=10.1109%2fLGRS.2017.2735801&partnerID=40&md5=7317b6c7547f2fc95f4c5a423d2828ab","Cloud and snow detection has significant remote sensing applications, while they share similar low-level features due to their consistent color distributions and similar local texture patterns. Thus, accurately distinguishing cloud from snow in pixel level from satellite images is always a challenging task with traditional approaches. To solve this shortcoming, in this letter, we proposed a deep learning system to classify cloud and snow with fully convolutional neural networks in pixel level. Specifically, a specially designed fully convolutional network was introduced to learn deep patterns for cloud and snow detection from the multispectrum satellite images. Then, a multiscale prediction strategy was introduced to integrate the low-level spatial information and high-level semantic information simultaneously. Finally, a new and challenging cloud and snow data set was labeled manually to train and further evaluate the proposed method. Extensive experiments demonstrate that the proposed deep model outperforms the state-of-the-art methods greatly both in quantitative and qualitative performances. © 2017 IEEE."
"7006095466;7409792174;6506848305;","Simulation, modeling, and dynamically based parameterization of organized tropical convection for global climate models",2017,"10.1175/JAS-D-16-0166.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85018379930&doi=10.1175%2fJAS-D-16-0166.1&partnerID=40&md5=c033d7f278553cbda70a652788c128b7","A new approach for treating organized convection in global climate models (GCMs) referred to as multiscale coherent structure parameterization (MCSP) introduces physical and dynamical effects of organized convection that are missing from contemporary parameterizations. The effects of vertical shear are approximated by a nonlinear slantwise overturning model based on Lagrangian conservation principles. Simulation of the April 2009 Madden-Julian oscillation event during the Year of Tropical Convection (YOTC) over the Indian Ocean using the Weather Research and Forecasting (WRF) Model at 1.3-km grid spacing identifies self-similar properties for squall lines, MCSs, and superclusters embedded in equatorial waves. The slantwise overturning model approximates this observed self-similarity. The large-scale effects of MCSP are examined in two categories of GCM. First, large-scale convective systems simulated in an aquaplanet model are approximated by slantwise overturning with attention to convective momentum transport. Second, MCSP is utilized in the Community Atmosphere Model, version 5.5 (CAM5.5), as tendency equations for second-baroclinic heating and convective momentum transport. The difference between MCSP and CAM5.5 is a direct measure of the global effects of organized convection. Consistent with TRMM measurements, the MCSP generates large-scale precipitation patterns in the tropical warm pool and the adjoining locale; improves precipitation in the intertropical convergence zone (ITCZ), South Pacific convergence zone (SPCZ), and Maritime Continent regions; and affects tropical wave modes. In conclusion, the treatment of organized convection by MCSP is salient for the next generation of GCMs. © 2017 American Meteorological Society."
"7404736154;7203001286;7202262257;6507890800;","Importance of deposition processes in simulating the seasonality of the Arctic black carbon aerosol",2010,"10.1029/2009JD013478","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77957558612&doi=10.1029%2f2009JD013478&partnerID=40&md5=1830b230a7d12895496900c28eb5e400","Anthropogenic aerosol components in the Arctic troposphere, such as black carbon (BC), show a strong seasonal variation characterized by a peak in later winter and early spring. The seasonality, however, is not properly simulated by most existing global aerosol models. Using the Canadian global air quality model with an online aerosol algorithm-Global Environmental Multiscale model with Air Quality processes (GEM-AQ), this work investigates the mechanisms of the seasonal variation of the Arctic BC. Through enhancements to parameterizations of wet and dry depositions in the Canadian Aerosol Module (CAM), the GEM-AQ model is able to simulate the observed seasonality of BC over the Arctic. The observed seasonality of Arctic BC is mainly attributed to the seasonal changes in aerosol wet scavenging. Seasonal injection of aerosols (e.g., BC from the European and the former USSR sectors and to a less extent from the North Atlantic sector) also contributes to the seasonality of Arctic aerosols in the lower troposphere. Although dry deposition has little effect on the seasonal pattern of BC in the Arctic lower troposphere, it significantly changes BC surface concentration in the Arctic. The enhanced model suggests an annual budget of BC deposition to the Arctic of 0.11 Tg, a 10% increase over the original estimation. The enhanced GEM-AQ model also suggests that the below-cloud scavenging dominates the contribution of BC removal over the Arctic with an estimation of 48% for 2001, whereas the contributions of in-cloud scavenging and dry deposition contribute about 27% and 25%, respectively. The estimated global BC burden is 0.28 Tg, which implies a global average BC lifetime of 9.2 days, whereas the AeroCom project suggests a range of 4.9-11.4 days. © 2010 by the American Geophysical Union."
"7003776366;7102568500;55425142900;7201862174;7003700019;","Multiscale MHD simulation of a coronal mass ejection and its interaction with the magnetosphere-ionosphere system",2000,"10.1016/S1364-6826(00)00091-2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0040956875&doi=10.1016%2fS1364-6826%2800%2900091-2&partnerID=40&md5=a4531b5cbadcbce54d1d7a4c03eb5fd8","We report on the first comprehensive numerical simulation of a space weather event, starting with the generation of a CME and subsequently following this transient solar wind disturbance as it evolves into a magnetic cloud and travels through interplanetary space towards Earth where its interaction with the terrestrial magnetosphere-ionosphere system is also predicted as part of the simulation. © 2000 Elsevier Science B.V."
"56531065100;57208275387;57204914178;57203579680;6603653680;","Spatiotemporal patterns and characteristics of remotely sensed region heat islands during the rapid urbanization (1995–2015) of Southern China",2019,"10.1016/j.scitotenv.2019.04.088","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85064328893&doi=10.1016%2fj.scitotenv.2019.04.088&partnerID=40&md5=19f07576b52e5285fc82934e7a5483a1","Urban agglomeration has become the most salient feature of global urbanization in recent decades, while spatiotemporal patterns and evolution remain poorly understood in urban agglomerations, which limit the decision-makers to make more informed decisions to improve the regional environment. Here we selected one of the most rapidly urbanized regions in the world – Pearl River Delta Metropolitan Region (PRDR), located in southern China, as the case. Landsat images spanning from 1995 to 2015 were used to retrieve land surface temperature (LST). Four types of regional heat island (RHI) degree were defined for further analysis. Then multi-scale spatiotemporal patterns and characteristics of RHI were identified with the help of cloud-based computing, spatial and landscape analysis. We found that (1) traditional urban heat island (UHI) appears as an RHI on an urban agglomeration scale. In PRDR, we found RHI expended with increasing connectivity, especially in the estuary areas where isolated UHI gradually merged during the rapid urbanization. (2) The contribution of main cities in PRDR to RHI and the evolutionary trends and pattern, which is changed from a west-east to a southwest-northeast gradient, have been revealed. (3) Considering the scale effect and different RHI categories, we revealed that during the urbanization, the aggregation of the RHI is significant on a larger-scale, and the area of 4 °C ≤ Relative LST ≤ 8 °C is the stable and high-risk area, which provide scientific bases for the governance of the thermal environment on the regional scale. (4) The study also indicates the cooling effect of forests and water is better than that of grassland, while the cooling effect of grassland is uncertain. The methods and results of this study not only have implications on environmental planning and management in the PRDR but also provide useful insights into the thermal environment research and practice in other urban agglomerations. © 2019 Elsevier B.V."
"7005635934;8403752800;56188004100;6602547442;","Validation of the operational emergency response model at the Swedish Meteorological and Hydrological Institute using data from ETEX and the chernobyl accident",1998,"10.1016/S1352-2310(98)00175-7","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032404058&doi=10.1016%2fS1352-2310%2898%2900175-7&partnerID=40&md5=338025ad841965f1dabeb8fa2a94ae90","The Eulerian atmospheric tracer transport model MATCH (Multiscale Atmospheric Transport and Chemistry model) has been extended with a Lagrangian particle model treating the initial dispersion of pollutants from point sources. The model has been implemented at the Swedish Meteorological and Hydrological Institute in an emergency response system for nuclear accidents and can be activated on short notice to provide forecast concentration and deposition fields. The model has been used to simulate the transport of the inert tracer released during the ETEX experiment and the transport and deposition of 137Cs from the Chernobyl accident. Visual inspection of the results as well as statistical analysis shows that the extent, time of arrival and duration of the tracer cloud, is in good agreement with the observations for both cases, with a tendency towards over- prediction for the first ETEX release. For the Chernobyl case the simulated deposition pattern over Scandinavia and over Europe as a whole agrees with observations when observed precipitation is used in the simulation. When model calculated precipitation is used, the quality of the simulation is reduced significantly and the model fails to predict major features of the observed deposition field.The Eulerian atmospheric tracer transport model MATCH (Multiscale Atmospheric Transport and Chemistry model) has been extended with a Lagrangian particle model treating the initial dispersion of pollutants from point sources. The model has been implemented at the Swedish Meteorological and Hydrological Institute in an emergency response system for nuclear accidents and can be activated on short notice to provide forecast concentration and deposition fields. The model has been used to simulate the transport of the inert tracer released during the ETEX experiment and the transport and deposition of 137Cs from the Chernobyl accident. Visual inspection of the results as well as statistical analysis shows that the extent, time of arrival and duration of the tracer cloud, is in good agreement with the observations for both cases, with a tendency towards over-prediction for the first ETEX release. For the Chernobyl case the simulated deposition pattern over Scandinavia and over Europe as a whole agrees with observations when observed precipitation is used in the simulation. When model calculated precipitation is used, the quality of the simulation is reduced significantly and the model fails to predict major features of the observed deposition field."
"55751750800;20733898400;9334234800;6701574871;6602084752;","Multiscale performance of the ALARO-0 model for simulating extreme summer precipitation climatology in Belgium",2013,"10.1175/JCLI-D-12-00844.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84888050926&doi=10.1175%2fJCLI-D-12-00844.1&partnerID=40&md5=7e0c2b8d2305fb4a5b34bdc7731e3ff9","Daily summer precipitation over Belgium from the Aire Limitée Adaptation Dynamique Développement International (ALADIN) model and a version of the model that has been updated with physical parameterizations, the so-called ALARO-0 model [ALADIN and AROME (Application de la Recherche à l'Opérationnel à Meso-Echelle) combined model, first baseline version released in 1998], are compared with respect to station observations for the period 1961-90. The 40-yr European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-40) is dynamically downscaled using both models on a horizontal resolution of 40 km, followed by a one-way nesting on high spatial resolutions of 10 and 4 km. This setup allows us to explore the relative importance of spatial resolution versus parameterization formulation on the model skill to correctly simulate extreme daily precipitation. Model performances are assessed through standard statistical errors and density, frequency, and quantile distributions as well as extreme value analysis, using the peak-over-threshold method and generalized Pareto distribution. The 40-km simulations of ALADIN and ALARO-0 show similar results, both reproducing the observations reasonably well. For the high-resolution simulations, ALARO-0 at both 10 and 4 km is in better agreement with the observations than ALADIN. The ALADIN model consistently produces too high precipitation rates. The findings demonstrate that the new parameterizations within the ALARO-0 model are responsible for a correct simulation of extreme summer precipitation at various horizontal resolutions. Moreover, this study shows that ALARO-0 is a good candidate model for regional climate modeling. © 2013 American Meteorological Society."
"57203054708;36987319800;","Multiscale modeling of the moist-convective atmosphere - A review",2011,"10.1016/j.atmosres.2011.08.009","https://www.scopus.com/inward/record.uri?eid=2-s2.0-80054791769&doi=10.1016%2fj.atmosres.2011.08.009&partnerID=40&md5=cb497772de3300b72c2bb9d8af875b6a","Multiscale modeling of the moist-convective atmosphere is reviewed with an emphasis on the recently proposed approaches of unified parameterization and Quasi-3D (Q3D) Multiscale Modeling Framework (MMF). The cumulus parameterization problem, which was introduced to represent the multiscale effects of moist convection, has been one of the central issues in atmospheric modeling. After a review of the history of cumulus parameterization, it is pointed out that currently there are two families of atmospheric models with quite different formulations of model physics, one represented by the general circulation models (GCMs) and the other by the cloud-resolving models (CRMs). Ideally, these two families of models should be unified so that a continuous transition of model physics from one kind to the other takes place as the resolution changes. This paper discusses two possible routes to achieve the unification. ROUTE I unifies the cumulus parameterization in conventional GCMs and the cloud microphysics parameterization in CRMs. A key to construct such a unified parameterization is to reformulate the vertical eddy transport due to subgrid-scale moist convection in such a way that it vanishes when the resolution is sufficiently high. A preliminary design of the unified parameterization is presented with supporting evidence for its validity. ROUTE II for the unification follows the MMF approach based on a coupled GCM/CRM, originally known as the ""super-parameterization"". The Q3D MMF is an attempt to broaden the applicability of the super-parameterization without necessarily using a fully three-dimensional CRM. This is accomplished using a network of cloud-resolving grids with gaps. The basic Q3D algorithm and highlights of preliminary results are reviewed. It is suggested that the hierarchy of future global models should form a ""Multiscale Modeling Network (MMN)"", which combines these two routes. With this network, the horizontal resolution of the dynamics core and that of the physical processes can be individually and freely chosen without changing the formulation of model physics. Development of such a network will represent a new phase of the history of numerical modeling of the atmosphere that can be characterized by the keyword ""unification"". © 2011 Elsevier B.V."
"55667075800;7003633691;6602378790;6603160936;6701854276;7005053289;7601601633;35262666500;24490696700;7102912169;6602361642;55650385900;","Correcting photolysis rates on the basis of satellite observed clouds",2007,"10.1029/2006JD007422","https://www.scopus.com/inward/record.uri?eid=2-s2.0-34547586421&doi=10.1029%2f2006JD007422&partnerID=40&md5=6161434df654688ecd37e032697d4ea4","Clouds can significantly affect photochemical activities in the boundary layer by altering radiation intensity, and therefore their correct specification in the air quality models is of outmost importance. In this study we introduce a technique for using the satellite observed clouds to correct photolysis rates in photochemical models. This technique was implemented in EPA's Community Multiscale Air Quality modeling system (CMAQ) and was tested over a 10 day period in August 2000 that coincided with the Texas Air Quality Study (TexAQS). The simulations were performed at 4 and 12 km grid size domains over Texas, extending east to Mississippi, for the period of 24 to 31 August 2000. The results clearly indicate that inaccurate cloud prediction in the model can significantly alter the predicted atmospheric chemical composition within the boundary layer and exaggerate or underpredict ozone concentration. Cloud impact is acute and more pronounced over the emission source regions and can lead to large errors in the model predictions of ozone and its by-products. At some locations the errors in ozone concentration reached as high as 60 ppb which was mostly corrected by the use of our technique. Clouds also increased the lifetime of ozone precursors leading to their transport out of the source regions and causing further ozone production down-wind. Longer lifetime for nitrogen oxides (NO<inf>x</inf> = NO + NO<inf>2</inf>) and its transport over regions high in biogenic hydrocarbon emissions (in the eastern part of the domain) led to increased ozone production that was missing in the control simulation. Over Houston-Galveston Bay area, the presence of clouds altered the chemical composition of the atmosphere and reduced the net surface removal of reactive nitrogen compounds. Use of satellite observed clouds significantly improved model predictions in areas impacted by clouds. Errors arising from an inconsistency in the cloud fields can impact the performance of photochemical models used for case studies as well as for air quality forecasting. Air quality forecast models often use the model results from the previous forecast (or some adjusted form of it) for the initialization of the new forecast. Therefore such errors can propagate into the future forecasts, and the use of observed clouds in the preparation of initial concentrations for air quality forecasting could be beneficial. Copyright 2007 by the American Geophysical Union."
"56647425100;25624545600;7102128820;57201793920;36161790500;45661986200;57200679067;","Aerosol impacts on drizzle properties in warm clouds from ARM mobile facility maritime and continental deployments",2014,"10.1002/2013JD021339","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84906533824&doi=10.1002%2f2013JD021339&partnerID=40&md5=102fc02d20f25d19815a265f67f98f5c","We have extensively evaluated the response of cloud base drizzle rate (Rcb; mmd1) in warm clouds to liquid water path (LWP; g m2) and to cloud condensation nuclei (CCN) number concentration (NCCN; cm3), an aerosol proxy. This evaluation is based on a 19 month long data set of Doppler radar, lidar, microwave radiometers, and aerosol observing systems from the Atmospheric Radiation Measurement (ARM) Mobile Facility deployments at the Azores and in Germany. Assuming 0.55% supersaturation to calculate NCCN, we found a power law Rcb = (0:0015±0:0009).LWP(1:68±0:05) NCCN(0:66±0:08), indicating that Rcb decreases by a factor of 2–3 as NCCN increases from 200 to 1000 cm3 for fixed LWP. Additionally, the precipitation susceptibility to NCCN ranges between 0.5 and 0.9, in agreement with values from simulations and aircraft measurements. Surprisingly, the susceptibility of the probability of precipitation from our analysis is much higher than that from CloudSat estimates but agrees well with simulations from a multiscale high-resolution aerosol-climate model. Although scale issues are not completely resolved in the intercomparisons, our results are encouraging, suggesting that it is possible for multiscale models to accurately simulate the response of LWP to aerosol perturbations. © 2014. American Geophysical Union. All Rights Reserved."
"57203423392;6506936772;37116464700;7006962390;14043428200;6602873453;12753020100;6701490421;6602914876;55951906300;57198005613;55684491100;15926468600;","The ash dispersion over Europe during the Eyjafjallajökull eruption - Comparison of CMAQ simulations to remote sensing and air-borne in-situ observations",2012,"10.1016/j.atmosenv.2011.06.077","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84855938592&doi=10.1016%2fj.atmosenv.2011.06.077&partnerID=40&md5=709c62fe214e83f2d416fcd06f4d20e3","The dispersion of volcanic ash over Europe after the outbreak of the Eyjafjallajökull on Iceland on 14 April 2010 has been simulated with a conventional three-dimensional Eulerian chemistry transport model system, the Community Multiscale Air Quality (CMAQ) model. Four different emission scenarios representing the lower and upper bounds of the emission height and intensity were considered. The atmospheric ash concentrations turned out to be highly variable in time and space. The model results were compared to three different kinds of observations: Aeronet aerosol optical depth (AOD) measurements, Earlinet aerosol extinction profiles and in-situ observations of the ash concentration by means of optical particle counters aboard the DLR Falcon aircraft. The model was able to reproduce observed AOD values and atmospheric ash concentrations. Best agreement was achieved for lower emission heights and a fraction of 2% transportable ash in the total volcanic emissions. The complex vertical structure of the volcanic ash layers in the free troposphere could not be simulated. Compared to the observations, the model tends to show vertically more extended, homogeneous aerosol layers. This is caused by a poor vertical resolution of the model at higher altitudes and a lack of information about the vertical distribution of the volcanic emissions. Only a combination of quickly available observations of the volcanic ash cloud and atmospheric transport models can give a comprehensive picture of ash concentrations in the atmosphere. © 2011 Elsevier Ltd."
"15054885700;7103002829;7102653983;","Transport processes in the tropical warm pool boundary layer. Part I: Spectral composition of fluxes",1996,"10.1175/1520-0469(1996)053<1187:TPITTW>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029777723&doi=10.1175%2f1520-0469%281996%29053%3c1187%3aTPITTW%3e2.0.CO%3b2&partnerID=40&md5=61b45716e0e5307c2608059b7dbf52cd","Spectral analysis of high-resolution turbulence data from the South Australian Cessna research aircraft is performed in an investigation of the multiscale nature of vertical transport processes in the atmospheric boundary layer (ABL) during TOGA COARE. The flights were conducted in the vicinity of large cloud cluster systems in the intertropical convergence zone, but away from the most intense mesoscale (100s of km) convective systems within the clusters. A number of very long (up to 430 km) and low (20-70 m) continuous data runs, composing an excellent dataset for studying the spectral composition of near-surface fluxes, are complemented by eight ""stack"" patterns providing important information regarding vertical variations. The ABL in these regions is found to be highly horizontally heterogeneous, due to the intrusion of cool air masses associated with precipitating cumulus and cumulonimbus clouds, and the action of lines of convection on a range of scales. Not only does this lead to large variations in the surface turbulent flux field, but it can also generate significant direct fluxes in a submesoscale (20-50 km) range at low altitudes, which are not expected to be controlled by ABL parameters. That is, enhanced motions resulting from the action of precipitating cumulus clouds in the presence of wind shear can lead to strong entrainment of air into the subcloud layer, and, in addition, gravity waves generated above the ABL can also influence subcloud motion. Analysis of the form and consistency of the cospectra suggests that, despite the absence of a clear ""gap"" in the power spectra of the major variables, it is nevertheless possible to achieve a reasonable partitioning between ""ABL turbulence"" and the larger-scale processes via a simple spectral separation with a crossover wavelength at around 2 km. This useful characteristic appears to reflect an ability of the ABL turbulence to maintain a high degree of coherency in spite of the changing conditions imposed by the mesoscale disturbances."
"6602447168;57200790631;7006802410;35448188800;35766085300;57208263371;8935341600;57189895059;57216596345;24070522000;7004296954;22958737600;57189896395;35344701200;7005967755;7005276494;16241933300;7005054220;7403276033;8728117200;7401715866;6506509805;57188639624;7102293768;7006107946;7401875806;6602298788;","Nitrogen dioxide observations from the Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument: Retrieval algorithm and measurements during DISCOVER-AQ Texas 2013",2016,"10.5194/amt-9-2647-2016","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84975687680&doi=10.5194%2famt-9-2647-2016&partnerID=40&md5=4f01cdd7393c4331f900765be4501e5f","The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument is a test bed for upcoming air quality satellite instruments that will measure backscattered ultraviolet, visible and near-infrared light from geostationary orbit. GeoTASO flew on the NASA Falcon aircraft in its first intensive field measurement campaign during the Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) Earth Venture Mission over Houston, Texas, in September 2013. Measurements of backscattered solar radiation between 420 and 465 nm collected on 4 days during the campaign are used to determine slant column amounts of NO2 at 250m×250m spatial resolution with a fitting precision of 2.2×1015 molecules cm-2. These slant columns are converted to tropospheric NO2 vertical columns using a radiative transfer model and trace gas profiles from the Community Multiscale Air Quality (CMAQ) model. Total column NO2 from GeoTASO is well correlated with ground-based Pandora observations (r = 0.90 on the most polluted and cloud-free day of measurements and r = 0.74 overall), with GeoTASO NO2 slightly higher for the most polluted observations. Surface NO2 mixing ratios inferred from GeoTASO using the CMAQ model show good correlation with NO2 measured in situ at the surface during the campaign (r = 0.85). NO2 slant columns from GeoTASO also agree well with preliminary retrievals from the GEO-CAPE Airborne Simulator (GCAS) which flew on the NASA King Air B200 (r = 0.81, slope = 0.91). Enhanced NO2 is resolvable over areas of traffic NOx emissions and near individual petrochemical facilities. © Author(s) 2016."
"55339822300;6602137606;","Forcing mechanisms governing diurnal, seasonal, and interannual variability in the boundary layer depths: Five years of continuous lidar observations over a suburban site near Paris",2015,"10.1002/2015JD023268","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84958811777&doi=10.1002%2f2015JD023268&partnerID=40&md5=1089e27508f10321fd51eb24783756ab","The atmospheric boundary layer (ABL) depth, ziis a fundamental variable of ABL and a climatologically important quantity. The exchange of energy between the Earth’s surface and the atmosphere is governed by turbulent mixing processes in the daytime ABL, and thus, zi is important for scaling turbulence and diffusion in both meteorological and air quality models. A long-term data set of zi was derived at the Site Instrumental de Recherche par Télédétection Atmosphérique (SIRTA) observatory near Paris, using measurements obtained from a ground-based vertically pointing aerosol lidar and an autonomous algorithm STRAT+. Using multiparameter observational data sets covering a 5 year period (October 2008 to September 2013), this study aims to explore two interconnected ABL research topics: brief climatology involving multiscale temporal zi variability (diurnal, seasonal, annual, and interannual) and the relationship between zi and near-surface thermodynamic parameters to determinemeteorological processes governing zi variability. Both the zi and the growth rate over SIRTA showed large seasonal variability with higher mean values in spring (1633m and 225mh_1) and summer (1947m and 247mh–1) than in autumn (1439m and 196mh–1) and winter (1033m and 149mh–1). Seasonal variability of daytime maximumzi is found to be strongly and linearly correlated with downwelling solar radiation at the surface (r = 0.92), while the dependence between daytime maximum zi and sensible heat flux (SHF) at seasonal scales is not fully linear, in particular, for summer months. Interannual variability is studied using deseasonalizedmonthly-mean anomalies of each variable. Conditional sampling and linear regression analyses between the anomalies of deseasonalized SHF and daytime maximum zishow (1) stronger correlation between the two parameters for the soil conditions compared to the wet soil conditions, (2) that zi anomalies were more dependent on SHF anomalies for negative than for positive boundary layer wind speed anomalies, and (3) in the summer season, zi anomalies varied more consistently with SHF anomalies for conditions with negative cloud cover anomalies than in conditions with positive cloud cover anomalies. © 2015. American Geophysical Union. All rights reserved."
"55823047900;8977001000;","Evaluating low-cloud simulation from an upgraded multiscale modeling framework model. Part I: Sensitivity to spatial resolution and climatology",2013,"10.1175/JCLI-D-12-00200.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84881630278&doi=10.1175%2fJCLI-D-12-00200.1&partnerID=40&md5=307a655812d4ae3b02c6c60a6ad1ac6a","The multiscale modeling framework, which replaces traditional cloud parameterizations with a 2D cloudresolving model (CRM) in each atmospheric column, is a promising approach to climate modeling. TheCRM component contains an advanced third-order turbulence closure, helping it to better simulate low-level clouds. In this study, two simulations are performed with 1.98 3 2.58 grid spacing but they differ in the vertical resolution. The number of model layers below 700 hPa increases from 6 in one simulation (IP-6L) to 12 in another (IP-12L) to better resolve the boundary layer. The low-cloud horizontal distribution and vertical structures in IP-12L are more realistic and its global mean is higher than in IP-6L and closer to that of CloudSat/Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) observations. The spatial patterns of tropical precipitation are significantly improved; for example, a single intertropical convergence zone (ITCZ) in the Pacific, instead of double ITCZs in an earlier study that used coarser horizontal resolution and a different dynamical core in its host general circulation model (GCM), and the intensity of the South Pacific convergence zone (SPCZ), and the ITCZ in the Atlantic is more realistic. Many aspects of the global seasonal climatology agree well with observations except for excessive precipitation in the tropics. In terms of spatial correlations and patterns in the tropical/subtropical regions, most surface/vertically integrated properties show greater improvement over the earlier simulation than that with lower vertical resolution. The relationships between low-cloud amount and several large-scale properties are consistent with those observed in five low-cloud regions. There is an imbalance in the surface energy budget, which is an aspect of the model that needs to be improved in the future. © 2013 American Meteorological Society."
"8922308700;7102266120;7006270084;7003666669;","The Explicit-Cloud Parameterized-Pollutant hybrid approach for aerosol-cloud interactions in multiscale modeling framework models: Tracer transport results",2008,"10.1088/1748-9326/3/2/025005","https://www.scopus.com/inward/record.uri?eid=2-s2.0-46749087994&doi=10.1088%2f1748-9326%2f3%2f2%2f025005&partnerID=40&md5=95a4e7a980357336f4704696e89319ce","All estimates of aerosol indirect effects on the global energy balance have either completely neglected the influence of aerosol on convective clouds or treated the influence in a highly parameterized manner. Embedding cloud-resolving models (CRMs) within each grid cell of a global model provides a multiscale modeling framework for treating both the influence of aerosols on convective as well as stratiform clouds and the influence of clouds on the aerosol, but treating the interactions explicitly by simulating all aerosol processes in the CRM is computationally prohibitive. An alternate approach is to use horizontal statistics (e.g., cloud mass flux, cloud fraction, and precipitation) from the CRM simulation to drive a single-column parameterization of cloud effects on the aerosol and then use the aerosol profile to simulate aerosol effects on clouds within the CRM. Here, we present results from the first component of the Explicit-Cloud Parameterized-Pollutant parameterization to be developed, which handles vertical transport of tracers by clouds. A CRM with explicit tracer transport serves as a benchmark. We show that this parameterization, driven by the CRM's cloud mass fluxes, reproduces the CRM tracer transport significantly better than a single-column model that uses a conventional convective cloud parameterization. © IOP Publishing Ltd."
"7003840159;7408527948;","Satellite observations during TOGA COARE: large-scale descriptive overview",1994,"10.1175/1520-0493(1994)122<2426:SODTCL>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0028582655&doi=10.1175%2f1520-0493%281994%29122%3c2426%3aSODTCL%3e2.0.CO%3b2&partnerID=40&md5=e7b82f2105e4054f8eb0fe94fee63c21","The 1992/93 Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (COARE) was specifically designed to monitor multiscale interactions between the atmosphere and ocean over the western Pacific warm pool. To help meet this objective, satellite observations were used to augment the enhanced COARE conventional data array in both space and time. In this paper the authors present a descriptive overview of convective cloud variability and sea surface temperature during the four-month intensive observational period (IOP) as revealed by satellite. Several satellite cloud signatures and patterns were detected during a strong west wind burst event in late December (1992), and these are described in detail. Time-composited sea surface temperature (SST) fields derived from satellite radiances indicate that significant regional variations in SST occurred during the passage of the west wind event. The satellite-derived SST fields compiled during the IOP are validated against in situ observations in the COARE domain, with a 0.25°C warm bias noted in the composited satellite data. -from Authors"
"57217081805;55947509300;56595135700;56784251200;47560910000;","Does HDR pre-processing improve the accuracy of 3D models obtained by means of two conventional SfM-MVS software packages? The case of the corral del veleta rock glacier",2015,"10.3390/rs70810269","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84939424270&doi=10.3390%2frs70810269&partnerID=40&md5=0218c3933f0ad39e8237390779944e1e","The accuracy of different workflows using Structure-from-Motion and Multi-View-Stereo techniques (SfM-MVS) is tested. Twelve point clouds of the Corral del Veleta rock glacier, in Spain, were produced with two different software packages (123D Catch and Agisoft Photoscan), using Low Dynamic Range images and High Dynamic Range compositions (HDR) for three different years (2011, 2012 and 2014). The accuracy of the resulting point clouds was assessed using benchmark models acquired every year with a Terrestrial Laser Scanner. Three parameters were used to estimate the accuracy of each point cloud: the RMSE, the Cloud-to-Cloud distance (C2C) and the Multiscale-Model-to-Model comparison (M3C2). The M3C2 mean error ranged from 0.084 m (standard deviation of 0.403 m) to 1.451 m (standard deviation of 1.625 m). Agisoft Photoscan overcome 123D Catch, producing more accurate and denser point clouds in 11 out 12 cases, being this work, the first available comparison between both software packages in the literature. No significant improvement was observed using HDR pre-processing. To our knowledge, this is the first time that the geometrical accuracy of 3D models obtained using LDR and HDR compositions are compared. These findings may be of interest for researchers who wish to estimate geomorphic changes using SfM-MVS approaches. © 2015 by the authors; licensee MDPI, Basel, Switzerland."
"55707488500;56611366900;57198616562;37018824600;7202970886;7402480218;","A comparison of multiscale variations of decade-long cloud fractions from six different platforms over the southern great plains in the United States",2014,"10.1002/2013JD019813","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84898827530&doi=10.1002%2f2013JD019813&partnerID=40&md5=bfc5e7385b90b0e7db3b1d86625c905c","This study compares 1997–2011 observationally based cloud fraction estimates from six different platforms (three ground-based estimates and three satellite-based estimates) over the Southern Great Plains, United States. The comparisons are performed at multiple temporal and spatial scales. The results show that 1997–2011 mean cloud fractions from the Active Remote Sensing of CLouds (ARSCL) and from the International Satellite Cloud Climatology Project (ISCCP) are significantly (at a 2% significance level, two-sided t test) larger than the others, having 0.08 and 0.15 larger mean diurnal variations, 0.08 and 0.13 larger mean annual variations, and 0.08 and 0.14 larger interannual variations, respectively. Although more high (low) clouds are likely a reason for larger ARSCL (ISCCP) cloud fractions, other mechanisms cannot be ruled out and require further investigations. Furthermore, half of the estimates exhibit a significant (at a 1% significance level, one-sided t test) overall increase of 0.08–0.10 in the annually averaged cloud fractions from 1998 to 2009; another half of the estimates exhibit little tendency of increase in this decade. Monthly cloud fractions from all the estimates exhibit quasi-Gaussian frequency distributions while the distributions of daily cloud fractions are found dependent on spatial scales. Cloud fractions from all the estimates show much larger seasonal variations than diurnal variations. Findings from this study suggest caution when using observationally based cloud fraction estimates for climate studies such as evaluating model performance and reinforce the need of consistency in defining and retrieving cloud fractions. © 2014. American Geophysical Union. All Rights Reserved."
"55823047900;8977001000;","Evaluating low-cloud simulation from an upgraded multiscale modeling framework model. Part II: Seasonal variations over the eastern pacific",2013,"10.1175/JCLI-D-12-00276.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880779500&doi=10.1175%2fJCLI-D-12-00276.1&partnerID=40&md5=2fd4dd71baf85fbee1ae301bf38573ce","The eastern Pacific is a climatologically important region. Conventional coupled atmosphere-ocean general circulation models produce positive sea surface temperature biases of 2-5 K in this region because of insufficient stratocumulus clouds. In this study, a global multiscale modeling framework (MMF), which replaces traditional cloud parameterizations with a 2D cloud-resolving model (CRM) in each atmospheric column, is used to examine the seasonal variations of this Pacific region. The CRM component contains an advanced third-order turbulence closure, helping it to better simulate boundary layer turbulence and lowlevel clouds. Compared to available satellite observations of cloud amount, liquid water path, cloud radiative effects, and precipitation, this MMF produces realistic seasonal variations of the eastern Pacific region, although there are some disagreements in the exact location of maximum cloudiness centers in the Peruvian region and the intensity of ITCZ precipitation. Analyses of profile- and subcloud-based decoupling measures reveal very small amplitudes of seasonal variations in the decoupling strength in the subtropics except for those regions off the subtropical coasts where the decoupling measures suggest that the boundary layers should be well coupled in all four seasons. In the Peruvian and Californian regions, the seasonal variations of low clouds are related to those in the boundary layer height and the strength of inversion. Factors that influence the boundary layer and the inversion, such as solar incident radiation, subcloud-layer turbulent mixing, and large-scale subsidence, can collectively explain the seasonal variations of low clouds rather than the deepening-warming mechanism of Bretherton and Wyant cited in earlier studies. © 2013 American Meteorological Society."
"57193882808;","Impact of ice microphysics on multiscale organization of tropical convection in two-dimensional cloud-resolving simulations",2003,"10.1256/qj.02.110","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0037286738&doi=10.1256%2fqj.02.110&partnerID=40&md5=a8f67d350708e1101be7f2b139c5fe68","This paper documents the impact of ice microphysics on the multiscale organization of tropical convection as simulated in two-dimensional cloud-resolving model simulations. Results from simulations which apply warm-rain microphysics are compared with results from a simulation which includes ice processes presented previously in this journal. In these simulations, moist convection and large-scale dynamics interact on an unprecedented range of spatial and temporal scales, albeit within a limited two-dimensional dynamical framework. In general, the large-scale organization of convection is similar in all simulations, although the scale and propagation speed of convectively-coupled gravity waves are different between the warm-rain and ice simulations. The most striking differences are on the mesoscale. The warm-rain simulations feature mesoscale convective systems with a reduced stratiform component and shorter life cycle than mesoscale systems in the simulation with ice microphysics. These impacts are consistent with previous modelling studies of the impact of ice microphysics on organized convection. It is hypothesized that the shorter life cycle of mesoscale convective systems in warm-rain simulations influences scale selection of the large-scale convectively-coupled gravity waves. Moreover, the vertical transport of horizontal momentum is affected as well. To the author's knowledge this is the first time the impact of cloud microphysics on mesoscale convective systems is shown to affect the coupling between deep convection and large-scale perturbations in the tropics."
"26532278200;36100360300;9233435600;57191850519;7005264401;","A new vertical grid nesting capability in the Weather Research and Forecasting (WRF) model",2016,"10.1175/MWR-D-16-0049.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84994107404&doi=10.1175%2fMWR-D-16-0049.1&partnerID=40&md5=a8047520017704831522e92495654120","Mesoscale atmospheric models are increasingly used for high-resolution (< 3 km) simulations to better resolve smaller-scale flow details. Increased resolution is achieved using mesh refinement via grid nesting, a procedure where multiple computational domains are integrated either concurrently or in series. A constraint in the concurrent nesting framework offered by the Weather Research and Forecasting (WRF) Model is that mesh refinement is restricted to the horizontal dimensions. This limitation prevents control of the grid aspect ratio, leading to numerical errors due to poor grid quality and preventing grid optimization. Herein, a procedure permitting vertical nesting for one-way concurrent simulation is developed and validated through idealized cases. The benefits of vertical nesting are demonstrated using both mesoscale and large-eddy simulations (LES). Mesoscale simulations of the Terrain-Induced Rotor Experiment (T-REX) show that vertical grid nesting can alleviate numerical errors due to large aspect ratios on coarse grids, while allowing for higher vertical resolution on fine grids. Furthermore, the coarsening of the parent domain does not result in a significant loss of accuracy on the nested domain. LES of neutral boundary layer flow shows that, by permitting optimal grid aspect ratios on both parent and nested domains, use of vertical nesting yields improved agreement with the theoretical logarithmic velocity profile on both domains. Vertical grid nesting in WRF opens the path forward for multiscale simulations, allowing more accurate simulations spanning a wider range of scales than previously possible. © 2016 American Meteorological Society."
"7004978125;56434851400;","A multiscale model for the intraseasonal impact of the diurnal cycle over the maritime continent on the Madden-Julian oscillation",2016,"10.1175/JAS-D-15-0158.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84958635409&doi=10.1175%2fJAS-D-15-0158.1&partnerID=40&md5=dbc5d6dd6c90f41b98f7cc070c3bdf8e","The eastward-propagating Madden-Julian oscillation (MJO) typically exhibits complex behavior during its passage over the Maritime Continent, sometimes slowly propagating eastward and other times stalling and even terminating there with large amounts of rainfall. This is a huge challenge for present-day numerical models to simulate. One possible reason is the inadequate treatment of the diurnal cycle and its scale interaction with the MJO. Here these two components are incorporated into a simple self-consistent multiscale model that includes one model for the intraseasonal impact of the diurnal cycle and another one for the planetary/intraseasonal circulation. The latter model is forced self-consistently by eddy flux divergences of momentum and temperature from a model for the diurnal cycle with two baroclinic modes, which capture the intraseasonal impact of the diurnal cycle. The MJO is modeled as the planetary-scale circulation response to a moving heat source on the synoptic and planetary scales. The results show that the intraseasonal impact of the diurnal cycle during boreal winter tends to strengthen the westerlies (easterlies) in the lower (upper) troposphere in agreement with the observations. In addition, the temperature anomaly induced by the intraseasonal impact of the diurnal cycle can cancel that from the symmetric-asymmetric MJO with convective momentum transfer, yielding stalled or suppressed propagation of the MJO across the Maritime Continent. The simple multiscale model should be useful for the MJO in observations or more complex numerical models. © 2016 American Meteorological Society."
"56162305900;7005920812;7003666669;55405340400;23393856300;34772240500;55717074000;7006705919;55913183200;","A multiscale modeling framework model (superparameterized CAM5) with a higher-order turbulence closure: Model description and low-cloud simulations",2015,"10.1002/2014MS000375","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85027927850&doi=10.1002%2f2014MS000375&partnerID=40&md5=a5a97c6417bdb6deeeeecd42f9477445","In this study, a higher-order turbulence closure scheme, called Cloud Layers Unified By Binormals (CLUBB), is implemented into a Multiscale Modeling Framework (MMF) model to improve low-cloud simulations. The performance of CLUBB in MMF simulations with two different microphysics configurations (one-moment cloud microphysics without aerosol treatment and two-moment cloud microphysics coupled with aerosol treatment) is evaluated against observations and further compared with results from the Community Atmosphere Model, Version 5 (CAM5) with conventional cloud parameterizations. CLUBB is found to improve low-cloud simulations in the MMF, and the improvement is particularly evident in the stratocumulus-to-cumulus transition regions. Compared to the single-moment cloud microphysics, CLUBB with two-moment microphysics produces clouds that are closer to the coast and agrees better with observations. In the stratocumulus-to-cumulus transition regions, CLUBB with two-moment cloud microphysics produces short-wave cloud forcing in better agreement with observations, while CLUBB with single-moment cloud microphysics overestimates short-wave cloud forcing. CLUBB is further found to produce quantitatively similar improvements in the MMF and CAM5, with slightly better performance in the MMF simulations (e.g., MMF with CLUBB generally produces low clouds that are closer to the coast than CAM5 with CLUBB). Improved low-cloud simulations in MMF make it an even more attractive tool for studying aerosol-cloud-precipitation interactions. Key Points: A higher-order closure is implemented in SPCAM5 CLUBB performs better in two-moment microphysics than in one-moment microphysics CLUBB produces quantitatively similar improvements in the MMF and CAM5 © 2015. The Authors."
"55511388600;6602999057;","The formation of a large summertime saharan dust plume: Convective and synoptic-scale analysis",2014,"10.1002/2013JD020667","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84896980249&doi=10.1002%2f2013JD020667&partnerID=40&md5=7791d927030b1b0d97e888a584681f9c","Haboobs are dust storms produced by the spreading of evaporatively cooled air from thunderstorms over dusty surfaces and are a major dust uplift process in the Sahara. In this study observations, reanalysis, and a high-resolution simulation using the Weather Research and Forecasting model are used to analyze the multiscale dynamics which produced a long-lived (over 2 days) Saharan mesoscale convective system (MCS) and an unusually large haboob in June 2010. An upper level trough and wave on the subtropical jet 5 days prior to MCS initiation produce a precipitating tropical cloud plume associated with a disruption of the Saharan heat low and moistening of the central Sahara. The restrengthening Saharan heat low and a Mediterranean cold surge produce a convergent region over the Hoggar and Aïr Mountains, where small convective systems help further increase boundary layer moisture. Emerging from this region the MCS has intermittent triggering of new cells, but later favorable deep layer shear produces a mesoscale convective complex. The unusually large size of the resulting dust plume (over 1000 km long) is linked to the longevity and vigor of the MCS, an enhanced pressure gradient due to lee cyclogenesis near the Atlas Mountains, and shallow precipitating clouds along the northern edge of the cold pool. Dust uplift processes identified are (1) strong winds near the cold pool front, (2) enhanced nocturnal low-level jet within the aged cold pool, and (3) a bore formed by the cold pool front on the nocturnal boundary layer. © 2014. The Authors."
"6602759321;42162284000;","Digital Elevation Model from the Best Results of Different Filtering of a LiDAR Point Cloud",2012,"10.1111/j.1467-9671.2012.01335.x","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84867430258&doi=10.1111%2fj.1467-9671.2012.01335.x&partnerID=40&md5=a706df70d9a1c18ae100eac18ddccd66","The LiDAR point clouds captured with airborne laser scanning provide considerably more information about the terrain surface than most data sources in the past. This rich information is not simply accessed and convertible to a high quality digital elevation model (DEM) surface. The aim of the study is to generate a homogeneous and high quality DEM with the relevant resolution, as a 2.5D surface. The study is focused on extraction of terrain (bare earth) points from a point cloud, using a number of different filtering techniques accessible by selected freeware. The proposed methodology consists of: (1) assessing advantages/disadvantages of different filters across the study area, (2) regionalization of the area according to the most suitable filtering results, (3) data fusion considering differently filtered point clouds and regions, and (4) interpolation with a standard algorithm. The resulting DEM is interpolated from a point cloud fused from partial point clouds which were filtered with multiscale curvature classification (MCC), hierarchical robust interpolation (HRI), and the LAStools filtering. An important advantage of the proposed methodology is that the selected landscape and datasets properties have been more holistically studied, with applied expert knowledge and automated techniques. The resulting highly applicable DEM fulfils geometrical (numerical), geomorphological (shape), and semantic quality properties. © 2012 Blackwell Publishing Ltd."
"7101661890;7006095466;","Characterization of momentum transport associated with organized moist convection and gravity waves",2010,"10.1175/2010JAS3418.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77958583383&doi=10.1175%2f2010JAS3418.1&partnerID=40&md5=d181bf4d8c62ed42df1d7b5cfd52e534","Tropical convection is inherently multiscalar, involving complex fields of clouds and various regimes of convective organization ranging from small disorganized cumulus up to large organized convective clusters. In addition to being a crucial component of the atmospheric water cycle and the global heat budget, tropical convection induces vertical fluxes of horizontal momentum. There are two main contributions to the momentum transport. The first resides entirely in the troposphere and is due to ascent, descent, and organized circulations associated with precipitating convective systems. The second resides in the troposphere, stratosphere, and farther aloft and is caused by vertically propagating gravity waves. Both the convective momentum transport and the gravity wave momentum flux must be parameterized in general circulation models; yet in existing parameterizations, these two processes are treated independently. This paper examines the relationship between the convective momentum transport and convectively generated gravity wave momentum flux by utilizing idealized simulations of multiscale tropical convection in different wind shear conditions. The simulations produce convective systems with a variety of regimes of convective organization and therefore different convective momentum transport properties and gravity wave spectra. A number of important connections are identified, including a consistency in the sign of the momentum transports in the lower troposphere and stratosphere that is linked to the generation of gravity waves by tilted convective structures. These results elucidate important relationships between the convective momentum transport and the gravity wave momentum flux that will be useful for interlinking their parameterization in the future. © 2010 American Meteorological Society."
"7102261205;7006437064;6603506954;7401491148;7202572566;","The physics of substorms as revealed by the ISTP",1999,"10.1016/S1464-1917(98)00028-2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032795398&doi=10.1016%2fS1464-1917%2898%2900028-2&partnerID=40&md5=ff3a300a4a4bcade630ddd9155f06d1d","Spacecraft and ground data combined with multiscale computer models developed by the ISTP program are providing a new and coherent understanding of the magnetospheric substorms and storms. Global MHD simulations that include ionospheric response are dynamically driven by upstream satellite data and allow for direct comparison with the field and flow quantities measured by magnetospheric satellites, ground data and images from the POLAR satellite. Through the combined analysis of the simulations and observations, the first unified picture of a substorm from the magnetospheric and ionospheric viewpoint is currently emerging. Here we use MHD simulations of two particularly well observed and analyzed events to explore the factors that trigger and organize the substorm elements into a coherent entity. The first event - March 9, 1995 - produces clear evidence that impulsive penetration of a large electric field in the vicinity of -8 to -10 R(E), possibly associated with magnetosonic energy focusing, acts as a trigger for substorm initiation. It is the element that connects the ionospheric to magnetospheric substorm. Particularly impressive is the timing of the chain of events and indices observed on the ground and their proxies computed in the simulation. This simulation is complemented by a 'theoretician's' simulation, a step function transition of the IMF from northward to southward, which clarifies the physics of energy penetration into the magnetosphere and demonstrates Poynting flux focusing in the near earth tail. The second event - January 10-11, 1997 - was driven by the impact of a magnetic cloud in the magnetosphere. It induced major disturbances in the magnetosphere and the groundand resulted in the loss of a geosynchronous ATT satellite. It is a simulation 'tour de force' and used continuous upstream data over 36 hours as input. The results provide a graphical and fascinating view of the global magnetospheric and tail response to a magnetic cloud impinging upstream, illustrate the importance of dynamics and indicate that pressure impulses play a key role in providing the coherence required for substorms."
"57207942766;57201692252;56603873300;56041533100;55349285400;56637803900;","Multilevel cloud detection for high-resolution remote sensing imagery using multiple convolutional neural networks",2018,"10.3390/ijgi7050181","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047126958&doi=10.3390%2fijgi7050181&partnerID=40&md5=ec66fbd0ad09d1216c0e8edb5069fe8e","In high-resolution image data, multilevel cloud detection is a key task for remote sensing data processing. Generally, it is difficult to obtain high accuracy for multilevel cloud detection when using satellite imagery which only contains visible and near-infrared spectral bands. So, multilevel cloud detection for high-resolution remote sensing imagery is challenging. In this paper, a new multilevel cloud detection technique is proposed based on the multiple convolutional neural networks for high-resolution remote sensing imagery. In order to avoid input the entire image into the network for cloud detection, the adaptive simple linear iterative clustering (A-SCLI) algorithm was applied to the segmentation of the satellite image to obtain good-quality superpixels. After that, a new multiple convolutional neural networks (MCNNs) architecture is designed to extract multiscale features from each superpixel, and the superpixels are marked as thin cloud, thick cloud, cloud shadow, and non-cloud. The results suggest that the proposed method can detect multilevel clouds and obtain a high accuracy for high-resolution remote sensing imagery. © 2018 by the authors. Licensee MDPI, Basel, Switzerland."
"7403577184;7101801476;7202772927;7401701196;7401945370;8117864800;16643471600;","On the land-ocean contrast of tropical convection and microphysics statistics derived from trmm satellite signals and global storm-resolving models",2016,"10.1175/JHM-D-15-0111.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84966348873&doi=10.1175%2fJHM-D-15-0111.1&partnerID=40&md5=9128dee25a42263cc4dc886cac54c606","A 14-yr climatology of Tropical Rainfall Measuring Mission (TRMM) collocated multisensor signal statistics reveals a distinct land-ocean contrast as well as geographical variability of precipitation type, intensity, and microphysics. Microphysics information inferred from the TRMMPrecipitation Radar and Microwave Imager show a large land-ocean contrast for the deep category, suggesting continental convective vigor. Over land, TRMMshows higher echo-top heights and larger maximum echoes, suggesting taller storms and more intense precipitation, as well as larger microwave scattering, suggesting the presence ofmore/larger frozen convective hydrometeors. This strong land-ocean contrast in deep convection is invariant over seasonal andmultiyear time scales. Consequently, relatively short-term simulations from two global storm-resolving models can be evaluated in terms of their land-ocean statistics using the TRMM Triple-Sensor Three-Step Evaluation Framework via a satellite simulator. The models evaluated are the NASA Multiscale Modeling Framework (MMF) and the Nonhydrostatic Icosahedral Cloud Atmospheric Model (NICAM). While both simulations can represent convective land-ocean contrasts in warm precipitation to some extent, near-surface conditions over land are relatively moister in NICAM than MMF, which appears to be the key driver in the divergent warm precipitation results between the two models. Both theMMF and NICAM produced similar frequencies of large CAPE between land and ocean. The dry MMF boundary layer enhanced microwave scattering signals over land, but only NICAM had an enhanced deep convection frequency over land. Neither model could reproduce a realistic land-ocean contrast in deep convective precipitation microphysics. A realistic contrast between land and ocean remains an issue in global storm-resolving modeling. © 2016 American Meteorological Society."
"20434404100;6603427849;24338002400;7004496942;6602931427;6506396422;7202180152;7402889608;6507158791;7006850787;","A comparison of atmospheric composition using the Carbon Bond and Regional Atmospheric Chemistry Mechanisms",2013,"10.5194/acp-13-9695-2013","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884250123&doi=10.5194%2facp-13-9695-2013&partnerID=40&md5=253114731fa77c64a09b2dddcdf0ac3b","We incorporate the recently developed Regional Atmospheric Chemistry Mechanism (version 2, RACM2) into the Community Multiscale Air Quality modeling system for comparison with the existing 2005 Carbon Bond mechanism with updated toluene chemistry (CB05TU). Compared to CB05TU, RACM2 enhances the domain-wide monthly mean hydroxyl radical concentrations by 46% and nitric acid by 26%. However, it reduces hydrogen peroxide by 2%, peroxyacetic acid by 94%, methyl hydrogen peroxide by 19%, peroxyacetyl nitrate by 40%, and organic nitrate by 41%. RACM2 enhances ozone compared to CB05TU at all ambient levels. Although it exhibited greater overestimates at lower observed concentrations, it displayed an improved performance at higher observed concentrations. The RACM2 ozone predictions are also supported by increased ozone production efficiency that agrees better with observations. Compared to CB05TU, RACM2 enhances the domain-wide monthly mean sulfate by 10%, nitrate by 6%, ammonium by 10%, anthropogenic secondary organic aerosols by 42%, biogenic secondary organic aerosols by 5%, and in-cloud secondary organic aerosols by 7%. Increased inorganic and organic aerosols with RACM2 agree better with observed data. Any air pollution control strategies developed using the two mechanisms do not differ appreciably. © Author(s) 2013. CC Attribution 3.0 License."
"56611366900;55707488500;57198616562;37018824600;","Relationship between cloud radiative forcing, cloud fraction and cloud albedo, and new surface-based approach for determining cloud albedo",2011,"10.5194/acp-11-7155-2011","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79960664245&doi=10.5194%2facp-11-7155-2011&partnerID=40&md5=db1f7eb48628753dbf2f1c0339ed889e","This paper focuses on three interconnected topics: (1) quantitative relationship between surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo; (2) surface-based approach for measuring cloud albedo; (3) multiscale (diurnal, annual and inter-annual) variations and covariations of surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo. An analytical expression is first derived to quantify the relationship between cloud radiative forcing, cloud fraction, and cloud albedo. The analytical expression is then used to deduce a new approach for inferring cloud albedo from concurrent surface-based measurements of downwelling surface shortwave radiation and cloud fraction. High-resolution decade-long data on cloud albedos are obtained by use of this surface-based approach over the US Department of Energy's Atmospheric Radiaton Measurement (ARM) Program at the Great Southern Plains (SGP) site. The surface-based cloud albedos are further compared against those derived from the coincident GOES satellite measurements. The three long-term (1997-2009) sets of hourly data on shortwave cloud radiative forcing, cloud fraction and cloud albedo collected over the SGP site are analyzed to explore the multiscale (diurnal, annual and inter-annual) variations and covariations. The analytical formulation is useful for diagnosing deficiencies of cloud-radiation parameterizations in climate models. © 2011 Author(s)."
"55918817700;26643054400;","EMTACS: Development and regional-scale simulation of a size, chemical, mixing type, and soot shape resolved atmospheric particle model",2011,"10.1029/2010JD015030","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79551474201&doi=10.1029%2f2010JD015030&partnerID=40&md5=0d83f978a5ee41a8c5ebbae654636688","A new aerosol chemical transport model, the Eulerian Multiscale Tropospheric Aerosol Chemistry and dynamics Simulator (EMTACS) has been developed. This model resolves aerosol chemical composition, size distribution, mixing types, and shapes of fractal agglomerates in the atmosphere. These parameters are critical for accurate estimation of the hygroscopicity and optical properties of aerosols. The model implements a new aerosol dynamics module (Modal Aerosol Dynamics model for multiple Modes and fractal Shapes (MADMS)), which for the first time enables simulation of intermodal Brownian coagulation between two modes with very different size distributions using the modal moment approach. MADMS simulates Brownian coagulation for arbitrary fractal dimensions. Coagulation processes due to turbulence and sedimentation are also considered. The EMTACS model successfully reproduced the fractions of PM<inf>2.5</inf> to PM<inf>10</inf> of major inorganic aerosol components measured at Jeju Island in Korea in the spring of 2005 during the Atmospheric Brown Cloud-East Asian Regional Experiment 2005 (ABC-EAREX) campaign. The results indicate the capability of the model in interpreting the observed size distribution and mixing types of aerosol inorganic components. The spatial and temporal distribution of mixing types of inorganic components (nss-SO <inf>4</inf>2-, NO<inf>3</inf>-, and NH<inf>4</inf> +) during long-range transport in East Asia is also discussed. Copyright 2011 by the American Geophysical Union."
"7101959253;55843404000;7005626683;","Evaluation of hydrometeor occurrence profiles in the multiscale modeling framework climate model using atmospheric classification",2009,"10.1175/2009JCLI2638.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-70350023630&doi=10.1175%2f2009JCLI2638.1&partnerID=40&md5=e31b60ce5059b79a479a8cc4b3831134","Vertical profiles of hydrometeor occurrence from the multiscale modeling framework (MMF) climate model are compared with profiles observed by a vertically pointing millimeter wavelength cloud radar (located in the U.S. southern Great Plains) as a function of the large-scale atmospheric state. The atmospheric state is determined by classifying (or clustering) the large-scale (synoptic) fields produced by the MMF and a numerical weather prediction model using a neural network approach. The comparison shows that for coldfrontal and post-cold-frontal conditions theMMF produces profiles of hydrometeor occurrence that compare favorably with radar observations, while for warm-frontal conditions the model tends to produce hydrometeor fractions that are too large with too much cloud (nonprecipitating hydrometeors) above 7 km and too much precipitating hydrometeor coverage below 7 km. It is also found that the MMF has difficulty capturing the formation of low clouds and that, for all atmospheric states that occur during June, July, and August, the MMF produces too much high and thin cloud, especially above 10 km. © 2009 American Meteorological Society."
"6505827289;7005120823;6506723397;7102926738;","A multiscale examination of the 31 May 1998 Mechanicville, New York, Tornado",2005,"10.1175/WAF875.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-27544454631&doi=10.1175%2fWAF875.1&partnerID=40&md5=49269c8465208a88c36dd8abce598d5d","On 31 May 1998, an F3 tornado struck Mechanicville, New York, injuring 68 people and causing $71 million in damage. The tornado was part of a widespread, severe weather outbreak across the northeast United States. The synoptic conditions that caused the outbreak and the mesoscale and storm-scale environments that produced the tornado are discussed. The coupling of two strong upper-level jets and a very strong low-level jet, in association with an unseasonably strong surface cyclone, created a synoptic-scale environment favorable for severe weather. As the result of these jet interactions, a very warm, moist air mass was transported into the Northeast with an associated increase in the wind shear in the lower troposphere. A terrain-channeled low-level southerly flow up the Hudson Valley may have created a mesoscale environment that was especially favorable for tornadic supercell development by increasing storm-relative helicity in the low levels of the atmosphere and by transporting warm, moist air northward up the valley, leading to increased instability. A broken line of locally severe thunderstorms mo ved eastward across New York several hours prior to the tornado. The storm that produced the Mechanicville tornado developed over central New York ahead of this line of storms. As the line of storms moved east, it intensified into a solid line and bowed forward down the Mohawk Valley of New York. These storms were moving faster than the isolated supercell to the east and overtook the supercell where the eastern end of the Mohawk Valley opens into the Hudson Valley. Based on limited observational evidence and the results of simulations of idealized quasi-linear convective systems reported elsewhere in the literature, it is hypothesized that backed low-level flow ahead of a bookend vortex at the northern end of the bowing line of storms over the Mohawk Valley may have contributed to the tornadogenesis process as the squall line overtook and interacted with the intensifying supercell. © 2005 American Meteorological Society."
"55628587967;6507400558;55550388400;34870277200;7004978125;","Improved tropical modes of variability in the NCEP Climate Forecast System (Version 2) via a stochastic multicloud model",2017,"10.1175/JAS-D-17-0113.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85031101399&doi=10.1175%2fJAS-D-17-0113.1&partnerID=40&md5=e55d012d7b03c77b9b3ccfdbeb5cff87","A stochastic multicloud model (SMCM) convective parameterization, which mimics the interactions at subgrid scales of multiple cloud types, is incorporated into the National Centers for Environmental Prediction (NCEP) Climate Forecast System, version 2 (CFSv2), model (CFSsmcm) in lieu of the preexisting simplified Arakawa-Schubert (SAS) cumulus scheme. A detailed analysis of the tropical intraseasonal variability (TISV) and convectively coupled equatorial waves (CCEW) in comparison with the original (control) model and with observations is presented here. The last 10 years of a 15-yr-long climate simulation are analyzed. Significant improvements are seen in the simulation of the Madden-Julian oscillation (MJO) and most of the CCEWs as well as the Indian summer monsoon (ISM) intraseasonal oscillation (MISO). These improvements appear in the form of improved morphology and physical features of these waves. This can be regarded as a validation of the central idea behind the SMCM according to which organized tropical convection is based on three cloud types, namely, the congestus, deep, and stratiform cloud decks, that interact with each other and form a building block for multiscale convective systems. An adequate accounting of the dynamical interactions of this cloud hierarchy thus constitutes an important requirement for cumulus parameterizations to succeed in representing atmospheric tropical variability. SAS fails to fulfill this requirement, which is evident in the unrealistic physical structures of the major intraseasonal modes simulated by CFSv2 as documented here. © 2017AmericanMeteorological Society."
"55578807789;56856326800;57191420252;9738134000;56447810700;56222085000;","Automated reconstruction of building lods from airborne LiDAR point clouds using an improved morphological scale space",2017,"10.3390/rs9010014","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85010644486&doi=10.3390%2frs9010014&partnerID=40&md5=8b80a4148d7ae499d74e95243c0dfbfa","Reconstructing building models at different levels of detail (LoDs) from airborne laser scanning point clouds is urgently needed for wide application as this method can balance between the user's requirements and economic costs. The previous methods reconstruct building LoDs from the finest 3D building models rather than from point clouds, resulting in heavy costs and inflexible adaptivity. The scale space is a sound theory for multi-scale representation of an object from a coarser level to a finer level. Therefore, this paper proposes a novel method to reconstruct buildings at different LoDs from airborne Light Detection and Ranging (LiDAR) point clouds based on an improved morphological scale space. The proposed method first extracts building candidate regions following the separation of ground and non-ground points. For each building candidate region, the proposed method generates a scale space by iteratively using the improved morphological reconstruction with the increase of scale, and constructs the corresponding topological relationship graphs (TRGs) across scales. Secondly, the proposed method robustly extracts building points by using features based on the TRG. Finally, the proposed method reconstructs each building at different LoDs according to the TRG. The experiments demonstrate that the proposed method robustly extracts the buildings with details (e.g., door eaves and roof furniture) and illustrate good performance in distinguishing buildings from vegetation or other objects, while automatically reconstructing building LoDs from the finest building points. © 2016 by the authors; licensee MDPI, Basel, Switzerland."
"57197197616;9537062600;15823214600;25821662300;23991021100;56912918900;7102930120;","Interannual surface evolution of an Antarctic blue-ice moraine using multi-temporal DEMs",2016,"10.5194/esurf-4-515-2016","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84977147479&doi=10.5194%2fesurf-4-515-2016&partnerID=40&md5=823b70db015ac13326919d21908c48e4","Multi-temporal and fine-resolution topographic data products are increasingly used to quantify surface elevation change in glacial environments. In this study, we employ 3-D digital elevation model (DEM) differencing to quantify the topographic evolution of a blue-ice moraine complex in front of Patriot Hills, Heritage Range, Antarctica. Terrestrial laser scanning (TLS) was used to acquire multiple topographic datasets of the moraine surface at the beginning and end of the austral summer season in 2012/2013 and during a resurvey field campaign in 2014. A complementary topographic dataset was acquired at the end of season 1 through the application of structure from motion with multi-view stereo (SfM-MVS) photogrammetry to a set of aerial photographs acquired from an unmanned aerial vehicle (UAV). Three-dimensional cloud-to-cloud differencing was undertaken using the Multiscale Model to Model Cloud Comparison (M3C2) algorithm. DEM differencing revealed net uplift and lateral movement of the moraine crests within season 1 (mean uplift ∼ 0.10 m) and surface lowering of a similar magnitude in some inter-moraine depressions and close to the current ice margin, although we are unable to validate the latter. Our results indicate net uplift across the site between seasons 1 and 2 (mean 0.07 m). This research demonstrates that it is possible to detect dynamic surface topographical change across glacial moraines over short (annual to intra-annual) timescales through the acquisition and differencing of fine-resolution topographic datasets. Such data offer new opportunities to understand the process linkages between surface ablation, ice flow and debris supply within moraine ice. © 2016 Author(s)."
"8977001000;55823047900;","Evaluating low-cloud simulation from an upgraded multiscale modeling framework model. Part III: Tropical and subtropical cloud transitions over the Northern Pacific",2013,"10.1175/JCLI-D-12-00650.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84881628575&doi=10.1175%2fJCLI-D-12-00650.1&partnerID=40&md5=a3785d34dffc8a51af669091a1843c9c","An analysis of simulated cloud regime transitions along a transect from the subtropical California coast to the tropics for the northern summer season (June-August) is presented in this study. The Community Atmosphere Model, version 5 (CAM5), superparameterized CAM (SPCAM), and an upgraded SPCAM with intermediately prognostic higher-order closure (SPCAM-IPHOC) are used to perform global simulations by imposing climatological sea surface temperature and sea ice distributions. The seasonal-mean properties are compared with recent observations of clouds, radiation, and precipitation and with multimodel intercomparison results. There are qualitative agreements in the characteristics of cloud regimes along the transect among the three models. CAM5 simulates precipitation and shortwave radiative fluxes well but the stratocumulus-to-cumulus transition occurs too close to the coast of California. SPCAM-IPHOC simulates longwave radiative fluxes and precipitable water well, but with systematic biases in shortwave radiative fluxes. The broad, stronger ascending band in SPCAM is related to the large biases in the convective region but the characteristics of the stratocumulus region are still more realistic and the transition occurs slightly farther away from the coast than in CAM5. Even though SPCAM-IPHOC produces the most realistic seasonal-mean transition, it underestimates the mean gradient in low-cloud cover (LCC) across the mean transition location because of an overestimate of LCC in the transition and convective regions that shifts the transition locations farther from the coast. Analysis of two decoupling measures shows consistency in the mean location and the histogram of decoupling locations with those of LCC transition. CAM5, however, lacks such a consistency, suggesting a need for further refinement of its boundary layer cloud parameterization. © 2013 American Meteorological Society."
"55716217300;8420514500;","The impacts of multiscale weather systems on freezing rain and snowstorms over Southern China",2010,"10.1175/2009WAF2222253.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77955540046&doi=10.1175%2f2009WAF2222253.1&partnerID=40&md5=e9f27348fe9e62da32d31bce03ddda2d","This paper investigated the interactions between the synoptic patterns, quasi-stationary fronts, eastward propagating cloud clusters from the Tibetan Plateau, surface conditions, and atmospheric stratification processes associated with a 20-day event of freezing precipitation over southern China from January to February 2008. It was found that the long duration of the freezing precipitation process was primarily caused by stationary and anomalous synoptic weather patterns such as a blocking high pressure system in the northern branch and a trough in the south branch of the westerlies, which resulted in the convergence of cold air from northern China and warm, moist air from the south. The cloud clusters over the Tibetan Plateau propagated eastward and showed noticeable impacts in the local areas when they moved over southern China during several similar cloud propagation processes from January to February 2008. An east-west-oriented quasi-stationary front system in southern China, which is rare during the Asian winter monsoon season, is responsible for producing freezing precipitation and snowstorms. A stronger horizontal gradient of the iso-lines of the pseudo-equivalent potential temperature and higher temperatures at the inversion layer in the western part of the front than that in its eastern part can be found. At the same time, low-level moisture convergence ahead of the front enhanced the formation, development, and persistence of freezing precipitation in the west part of the front. The thickness of the warm layer and the temperature inversion layer also modulated the intensity and duration of freezing rain and ice pellets. Temperature from about -1° to -3°C and weak winds were found to be favorable meteorological factors at the surface level for freezing precipitation. These analysis results are synthesized into a conceptual model that coherently describes the physics processes associated with the synoptic features and quasi-stationary front system as well as the atmospheric stratification process during the freezing precipitation event. © 2010 American Meteorological Society."
"23570843600;8670472000;7003557662;","Using ARM observations to evaluate cloud and clear-sky radiation processes as simulated by the Canadian regional climate model GEM",2010,"10.1175/2009MWR2745.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77953194774&doi=10.1175%2f2009MWR2745.1&partnerID=40&md5=708878bb9a6e7d22a5c6173840eff5c6","The total downwelling shortwave (SWD) and longwave (LWD) radiation and its components are assessed for the limited-area version of the Global Environmental Multiscale Model (GEM-LAM) against Atmospheric Radiation Measurements (ARM) at two sites: the southern Great Plains (SGP) and the North Slope of Alaska (NSA) for the 1998-2005 period. The model and observed SWD and LWD are evaluated as a function of the cloud fraction (CF), that is, for overcast and clear-sky conditions separately, to isolate and analyze different interactions between radiation and 1) atmospheric aerosols and water vapor and 2) cloud liquid water. Through analysis of the mean diurnal cycle and normalized frequency distributions of surface radiation fluxes, the primary radiation error in GEM-LAM is seen to be an excess in SWD in the middle of the day. The SWD bias results from a combination of underestimated CF and clouds, when present, possessing a too-high solar transmissivity, which is particularly the case for optically thin clouds. Concurrent with the SWD bias, a near-surface warm bias develops in GEM-LAM, particularly at the SGP site in the summer. The ultimate cause of this warm bias is difficult to uniquely determine because of the range of complex interactions between the surface, atmospheric, and radiation processes that are involved. Possible feedback loops influencing this warm bias are discussed. The near-surface warm bias is the primary cause of an excess clear-sky LWD. This excess is partially balanced with respect to the all-sky LWD by an underestimated CF, which causes a negative bias in simulated all-sky emissivity. It is shown that there is a strong interaction between all the components influencing the simulated surface radiation fluxes with frequent error compensation, emphasizing the need to evaluate the individual radiation components at high time frequency. © 2010 American Meteorological Society."
"7006095466;","The multiscale organization of moist convection and the intersection of weather and climate",2010,"10.1029/2008GM000838","https://www.scopus.com/inward/record.uri?eid=2-s2.0-80051806765&doi=10.1029%2f2008GM000838&partnerID=40&md5=b91b7904bb50eba22cfb08e8a825ec94","Moist convection organizes into cloud systems of various sizes and kinds, a process with a dynamical basis and upscale connotations. Although organized precipitation systems have been extensively observed, numerically simulated, and dynamically modeled, our knowledge of their effects on weather and climate is far from complete. Convective organization is absent de facto from contemporary climate models because the salient dynamics are not represented by parameterizations and the model resolution is insufficient to represent them explicitly. Highresolution weather prediction models, fine-resolution cloud system models, and dynamical models address moist convective organization explicitly. As a key element in the seamless prediction of weather and climate on timescales up to seasonal, organized convection is the focus of the Year of Tropical Convection, an international collaborative project coordinated by the World Meteorological Organisation. This paper reviews the scientific basis of convective organization and progress toward comprehending its large-scale effects and representing them in global models. Copyright © 2010 by the American Geophysical Union."
"23019619200;56060986400;56250185400;","Harmattan, Saharan heat low, and West African monsoon circulation: Modulations on the Saharan dust outflow towards the North Atlantic",2017,"10.5194/acp-17-10223-2017","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85028702917&doi=10.5194%2facp-17-10223-2017&partnerID=40&md5=9425a0cc2571eed443bc2af47955e731","The outflow of dust from the northern African continent towards the North Atlantic is stimulated by the atmospheric circulation over North Africa, which modulates the spatio-temporal distribution of dust source activation and consequently the entrainment of mineral dust into the boundary layer, as well as the transport of dust out of the source regions. The atmospheric circulation over the North African dust source regions, predominantly the Sahara and the Sahel, is characterized by three major circulation regimes: (1) the harmattan (trade winds), (2) the Saharan heat low (SHL), and (3) the West African monsoon circulation. The strength of the individual regimes controls the Saharan dust outflow by affecting the spatio-temporal distribution of dust emission, transport pathways, and deposition fluxes.<br><br>This study aims at investigating the atmospheric circulation pattern over North Africa with regard to its role favouring dust emission and dust export towards the tropical North Atlantic. The focus of the study is on summer 2013 (June to August), during which the SALTRACE (Saharan Aerosol Long-range TRansport and Aerosol-Cloud interaction Experiment) field campaign also took place. It involves satellite observations by the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) flying on board the geostationary Meteosat Second Generation (MSG) satellite, which are analysed and used to infer a data set of active dust sources. The spatio-temporal distribution of dust source activation frequencies (DSAFs) allows for linking the diurnal cycle of dust source activations to dominant meteorological controls on dust emission. In summer, Saharan dust source activations clearly differ from dust source activations over the Sahel regarding the time of day when dust emission begins. The Sahara is dominated by morning dust source activations predominantly driven by the breakdown of the nocturnal low-level jet. In contrast, dust source activations in the Sahel are predominantly activated during the second half of the day, when downdrafts associated with deep moist convection are the major atmospheric driver. Complementary to the satellite-based analysis on dust source activations and implications from their diurnal cycle, simulations on atmosphere and dust life cycle were performed using the mesoscale atmosphere-dust model system COSMO-Muscat (COSMO: COnsortium for Small-scale MOdelling; Muscat: MUltiScale Chemistry Aerosol Transport Model). Fields from this simulation were analysed regarding the variability of the harmattan, the Saharan heat low, and the monsoon circulation as well as their impact on the variability of the Saharan dust outflow towards the North Atlantic. This study illustrates the complexity of the interaction among the three major circulation regimes and their modulation of the North African dust outflow. Enhanced westward dust fluxes frequently appear following a phase characterized by a deep SHL. Ultimately, findings from this study contribute to the quantification of the interannual variability of the atmospheric dust burden. © Author(s) 2017."
"57196489468;56520921400;","A case study of subdaily simulated and observed continental convective precipitation: CMIP5 and multiscale global climate models comparison",2013,"10.1002/2013GL057987","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84890528398&doi=10.1002%2f2013GL057987&partnerID=40&md5=aad45c8689c9c6205dc5b3ff05bbf84e","We analyze subdaily continental convective precipitation data relative to the Southeastern U.S. from gridded rain gauge measurements, conventional global climate models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) archive, and a multiscale GCM. GCMs react too quickly to local convective instability and, therefore, overestimate the incidence of middle rainfall events and underestimate the incidence of no, little, and heavy rainfall events. Moreover, GCMs overestimate the persistence of heavy precipitation and underestimate the persistence of no and light precipitation. In general, GCMs with suppression mechanisms in the treatments of convective precipitation compare best with rain gauge derived data and should be trusted more than the others when assessing the risk from extreme precipitation events. The multiscale GCM has the best estimate of the diurnal cycle and a good estimate of heavy rainfall persistence. ©2013. American Geophysical Union. All Rights Reserved."
"55519994900;23991212200;55411439700;","Robustness and sensitivities of central U.S. summer convection in the super-parameterized CAM: Multi-model intercomparison with a new regional EOF index",2013,"10.1002/grl.50597","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880549828&doi=10.1002%2fgrl.50597&partnerID=40&md5=0224148b803b7fd434913140c72f528d","Mesoscale convective systems (MCSs) can bring up to 60% of summer rainfall to the central United States but are not simulated by most global climate models. In this study, a new empirical orthogonal function based index is developed to isolate the MCS activity, similar to that developed by Wheeler and Hendon (2004) for the Madden-Julian Oscillation. The index is applied to compactly compare three conventional- and super-parameterized (SP) versions (3.0, 3.5, and 5.0) of the National Center for Atmospheric Research Community Atmosphere Model (CAM). Results show that nocturnal, eastward propagating convection is a robust effect of super-parameterization but is sensitive to its specific implementation. MCS composites based on the index show that in SP-CAM3.5, convective MCS anomalies are unrealistically large scale and concentrated, while surface precipitation is too weak. These aspects of the MCS signal are improved in the latest version (SP-CAM5.0), which uses high-order microphysics. Key Points A new EOF based index compactly evaluates the mid-latitude MCS signal in GCMs Central US summer MCS physics is a robust effect of cloud super-parameterization The MCS signal is most realistic in SP-CAM5.0 that uses high-order microphysics ©2013. American Geophysical Union. All Rights Reserved."
"55716092000;9244954000;9249239700;7003278104;7101801476;7202772927;7404829395;7003406400;","Partitioning CloudSat ice water content for comparison with upper tropospheric ice in global atmospheric models",2011,"10.1029/2010JD015179","https://www.scopus.com/inward/record.uri?eid=2-s2.0-80054827157&doi=10.1029%2f2010JD015179&partnerID=40&md5=1d1abe0cd95b8acf2a4148985895bfeb","The ice cloud estimates in current global models exhibit significant inconsistency, resulting in a significant amount of uncertainties in climate forecasting. Vertically resolved ice water content (IWC) is recently available from new satellite products, such as CloudSat, providing important observational constraints for evaluating the global models. To account for the varied nature of the model parameterization schemes, it is valuable to develop methods to distinguish the cloud versus precipitating ice components from the remotely sensed estimates in order to carry out meaningful model-data comparisons. The present study develops a new technique that partitions CloudSat total IWC into small and large ice hydrometeors, using the ice particle size distribution (PSD) parameters provided by the retrieval algorithm. The global statistics of CloudSat-retrieved PSD are analyzed for the filtered subsets on the basis of convection and precipitation flags to identify appropriate particle size separation. Results are compared with previous partitioning estimates and suggest that the small particles contribute to ∼25-45% of the global mean total IWC in the upper to middle troposphere. Sensitivity measures with respect to the PSD parameters and the retrieval algorithm are presented. The current estimates are applied to evaluate the IWC estimates from the European Centre for Medium-Range Weather Forecasts model and the finite-volume multiscale modeling framework model, pointing to specific areas of potential model improvements. These results are discussed in terms of applications to model diagnostics, providing implications for reducing the uncertainty in the model representation of cloud feedback and precipitation. Copyright 2011 by the American Geophysical Union."
"36337552300;57190613121;7003838600;15045412300;6701778830;56000281400;","High-resolution GEM-LAM application in marine fog prediction: Evaluation and diagnosis",2010,"10.1175/2009WAF2222337.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77955520541&doi=10.1175%2f2009WAF2222337.1&partnerID=40&md5=624eafe6305fc1db8f142faea61bc7f1","A three-level nested rendering of a high-resolution limited-area model version of the Global Environment Multiscale configuration (GEM-LAM), running quasi-operationally at the Canadian Meteorological Centre, is evaluated for its capabilities in marine fog prediction. The model shows a general underestimation of the cloud water content at lower levels that is utilized as one of the proxies for fog and/or low stratus. A warm and dry tendency also appears at the lowest layer (a few hundreds of meters above the surface) of the vertical profiles and at screen level. The condensation scheme directly generates/dissipates the cloud water content (or fog) while boundary layer processes [such as moist turbulent kinetic energy (MoisTKE)] vertically redistribute it. However, the results presented here emphasize the significance of the accurate initial and vertical velocity fields, as well as the interactions between the condensation scheme and the radiation scheme that interacts fully with clouds. These conclusions suggest that a delicate balance among the different physical processes and dynamics is needed for a successful fog forecast. © 2010 American Meteorological Society."
"8832722300;6604000335;8680433600;7005067383;6603518408;","Case study of inhomogeneous cloud parameter retrieval from MODIS data",2005,"10.1029/2005GL022791","https://www.scopus.com/inward/record.uri?eid=2-s2.0-24944454952&doi=10.1029%2f2005GL022791&partnerID=40&md5=e2cd90cda58ca25589b2178206807501","Cloud parameter retrieval of inhomogeneous and fractional clouds is performed for a stratocumulus scene observed by MODIS at a solar zenith angle near 60°. The method is based on the use of neural network technique with multispectral and multiscale information. It allows to retrieve six cloud parameters, i.e. pixel means and standard deviations of optical thickness and effective radius, fractional cloud cover, and cloud top temperature. Retrieved cloud optical thickness and effective radius are compared to those retrieved with a classical method based on the homogeneous cloud assumption. Subpixel fractional cloud cover and optical thickness inhomogeneity are compared with their estimates obtained from 250m pixel observations; this comparison shows a fairly good agreement. The cloud top temperature appears also retrieved quite suitably. Copyright 2005 by the American Geophysical Union."
"6506539494;6701627654;","Recognition and characterization of hierarchical interstellar structure. I. Correlation function",1990,"10.1086/191411","https://www.scopus.com/inward/record.uri?eid=2-s2.0-4243283500&doi=10.1086%2f191411&partnerID=40&md5=f8a0bc310e74f48d9b2fa3b3aefb0043","We consider the problem of the quantitative description of multiscale structure in interstellar cloud complexes and gravitational collapse calculations, with an emphasis on the recognition and characterization of hierarchical fragmentation structure. The present paper discusses the response of the two-point correlation function to a variety of analytical models for density structure, for simple clustering of pointlike clouds to more complex models involving clouds with a distribution of sizes and densities and hierarchical substructure. By expressing the density distribution as the superposition of individual clouds, it is shown that the correlation function generates two types of terms: those involving each cloud's density convolved with itself (""self terms"") and those involving pairs of different clouds (""cross terms""). The cross terms contain the relational information concerning spatial structure, but only as the frequency distribution of cloud pair separations. A self-similar hierarchical distribution of clouds will result in cross-term contributions to the correlation function which are periodic in the logarithm of the spatial lag. However, it is shown that these features are smeared and obscured by the finite sizes of the clouds involved in the cross terms, by the self terms, by edge effects, and by stochastic variations in cloud positions relative to a perfect geometrical hierarchy. It is emphasized that major distortions of the correlation function are introduced by the presence of any image features with size scales a significant fraction of the image size, such as gradients or a small number of large clouds. Such features, which are necessarily present for hierarchical systems, will control the shape of the correlation function at small separations and produce anticorrelations at intermediate lags and recorrelations at large lags. This behavior only reflects the gradients and separations of large clouds, which are statistically irrelevant and can be much more easily studied by visual inspection of the original density map. Most published attempts to interpret the correlation function for interstellar structures, except those that are restricted to the detection of clustering of pointlike sources, appear to be dominated by these effects."
"8316438800;54968014000;","Metallicity fluctuation statistics in the interstellar medium and young stars - I. Variance and correlation",2018,"10.1093/mnras/stx3286","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85045222548&doi=10.1093%2fmnras%2fstx3286&partnerID=40&md5=4d4865fabf0c4590eaac4a4a244b616f","The distributions of a galaxy's gas and stars in chemical space encode a tremendous amount of information about that galaxy's physical properties and assembly history. However, present methods for extracting information from chemical distributions are based either on coarse averages measured over galactic scales (e.g. metallicity gradients) or on searching for clusters in chemical space that can be identified with individual star clusters or gas clouds on ~1 pc scales. These approaches discard most of the information, because in galaxies gas and young stars are observed to be distributed fractally, with correlations on all scales, and the same is likely to be true of metals. In this paper we introduce a first theoretical model, based on stochastically forced diffusion, capable of predicting the multiscale statistics of metal fields. We derive the variance, correlation function, and power spectrum of the metal distribution from first principles, and determine how these quantities depend on elements' astrophysical origin sites and on the large-scale properties of galaxies. Among other results, we explain for the first time why the typical abundance scatter observed in the interstellar media of nearby galaxies is ≈0.1 dex, and we predict that this scatter will be correlated on spatial scales of ~0.5-1 kpc, and over time-scales of~100-300 Myr. We discuss the implications of our results for future chemical tagging studies. © 2017 The Author(s)."
"57198945375;57203579757;","A study of multiscale initial condition perturbation methods for convection-permitting ensemble forecasts",2016,"10.1175/MWR-D-16-0056.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84978043632&doi=10.1175%2fMWR-D-16-0056.1&partnerID=40&md5=9b03725fe90e273161225f8a32429d27","The impacts of multiscale flow-dependent initial condition (IC) perturbations for storm-scale ensemble forecasts of midlatitude convection are investigated using perfect-model observing system simulation experiments. Several diverse cases are used to quantitatively and qualitatively understand the impacts of different IC perturbations on ensemble forecast skill. Scale dependence of the results is assessed by evaluating 2-h storm-scale reflectivity forecasts separately from hourly accumulated mesoscale precipitation forecasts. Forecasts are initialized with different IC ensembles, including an ensemble of multiscale perturbations produced by a multiscale data assimilation system, mesoscale perturbations produced at a coarser resolution, and filtered multiscale perturbations. Mesoscale precipitation forecasts initialized with the multiscale perturbations are more skillful than the forecasts initialized with the mesoscale perturbations at several lead times. This multiscale advantage is due to greater consistency between the IC perturbations and IC uncertainty. This advantage also affects the short-term, smaller-scale forecasts. Reflectivity forecasts on very small scales and very short lead times are more skillful with the multiscale perturbations as a direct result of the smaller-scale IC perturbation energy. The small-scale IC perturbations also contribute to some improvements to the mesoscale precipitation forecasts after the ~5-h lead time. Altogether, these results suggest that the multiscale IC perturbations provided by ensemble data assimilation on the convection-permitting grid can improve storm-scale ensemble forecasts by improving the sampling of IC uncertainty, compared to downscaling of IC perturbations from a coarser-resolution ensemble. © 2016 American Meteorological Society."
"55608476300;15034793900;48260990900;36990982800;","Automated Detection of Three-Dimensional Cars in Mobile Laser Scanning Point Clouds Using DBM-Hough-Forests",2016,"10.1109/TGRS.2016.2537830","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84976338968&doi=10.1109%2fTGRS.2016.2537830&partnerID=40&md5=5fb241e07ea656b1e4ca0e7e263b233c","This paper presents an automated algorithm for rapidly and effectively detecting cars directly from large-volume 3-D point clouds. Rather than using low-order descriptors, a multilayer feature generation model is created to obtain high-order feature representations for 3-D local patches through deep learning techniques. To handle cars with different levels of incompleteness caused by data acquisition ways and occlusions, a hierarchical visibility estimation model is developed to augment Hough voting. Considering scale and orientation variations in the azimuth direction, a set of multiscale Hough forests is constructed to rotationally cast votes to estimate cars' centroids. Quantitative assessments show that the proposed algorithm achieves average completeness, correctness, quality, and F1-measure of 0.94, 0.96, 0.90, and 0.95, respectively, in detecting 3-D cars. Comparative studies also demonstrate that the proposed algorithm outperforms the other four existing algorithms in accurately and completely detecting 3-D cars from large-scale 3-D point clouds. © 2016 IEEE."
"35095482200;7403282069;8977001000;7006783796;6506234624;","Mean structure and diurnal cycle of southeast Atlantic boundary layer clouds: Insights from satellite observations and multiscale modeling framework simulations",2015,"10.1175/JCLI-D-14-00368.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84920277796&doi=10.1175%2fJCLI-D-14-00368.1&partnerID=40&md5=67dd9d7706d1d9904652b0744b4b2f89","The mean structure and diurnal cycle of southeast (SE) Atlantic boundary layer clouds are described with satellite observations andmultiscalemodeling framework (MMF) simulations during austral spring (September- November). Hourly resolution cloud fraction (CF) and cloud-top height (HT) are retrieved from Meteosat-9 radiances using modified Clouds and the Earth's Radiant Energy System (CERES) Moderate Resolution Imaging Spectroradiometer (MODIS) algorithms, whereas liquid water path (LWP) is from the University of Wisconsin microwave satellite climatology. The MMF simulations use a 2D cloud-resolving model (CRM) that contains an advanced third-order turbulence closure to explicitly simulate cloud physical processes in every grid column of a general circulationmodel. The model accurately reproduces themarine stratocumulus spatial extent and cloud cover. The mean cloud cover spatial variability in the model is primarily explained by the boundary layer decoupling strength, whereas a boundary layer shoaling accounts for a coastal decrease in CF. Moreover, the core of the stratocumulus cloud deck is concomitant with the location of the strongest temperature inversion. Although the model reproduces the observed westward boundary layer deepening and the spatial variability of LWP, it overestimates LWP by 50%.Diurnal cycles ofHT, CF, and LWP from satellites and the model have the same phase, with maxima during the early morning and minima near 1500 local solar time,which suggests that the diurnal cycle is driven primarily by solar heating. Comparisons with the SE Pacific cloud deck indicate that the observed amplitude of the diurnal cycle is modest over the SE Atlantic, with a shallower boundary layer as well. The model qualitatively reproduces these interregime differences. © 2015 American Meteorological Society."
"24080667300;57200055610;7202422359;6603661476;","Diagnosis of an underestimation of summertime sulfate using the Community Multiscale Air Quality model",2011,"10.1016/j.atmosenv.2011.06.029","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79960837299&doi=10.1016%2fj.atmosenv.2011.06.029&partnerID=40&md5=a141e5b95a0b4072e2420a9d5b814334","We evaluate the simulations of SO2 and sulfate using the Community Multiscale Air Quality model (CMAQ) version 4.6 with the observations over the United States in 2002. MM5 was used for meteorological simulations. While the general seasonal cycles of SO2 and sulfate are simulated well by the model, we find significant systematic biases in the summer. The model low bias in sulfate is considerably more severe than the model bias in SO2. Both ACM and RADM schemes are used in the model to test the sensitivities of simulated sulfate to cloud processing. We carry out detailed modeling analysis and diagnostics for July 2002. Compared to satellite observations of cloud liquid water path, CMAQ cloud modules greatly overestimates convective (sub-grid) precipitating clouds, leading to large overestimation of sulfate wet scavenging. Limiting convective precipitating cloud fraction in the cloud modules to &lt;10% and hence significantly reducing wet scavenging lead to much improved agreement between simulated and observed sulfate. The average lifetime of sulfate in the model increases from 1-2 days to 3-4 days for July. We show that a potential model problem of excessive wet scavenging of sulfate does not necessarily lead to apparent problems in model simulations of sulfate wet deposition rate compared to surface observations. In general, there is still a lack of direct observational constraints from air quality monitoring measurements on model simulated cloud processing of SO2 and sulfate. © 2011 Elsevier Ltd."
"16309604700;7601492669;7401945370;9535769800;25647939800;7801685271;","Multiscale interactions in the life cycle of a tropical cyclone simulated in a global cloud-system-resolving model. Part II: System-scale and mesoscale processes",2010,"10.1175/2010MWR3475.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-78651071307&doi=10.1175%2f2010MWR3475.1&partnerID=40&md5=c87cde94623ed3a4c6a64aaf4b70306b","The life cycle of Tropical Storm Isobel was simulated reasonably well in the Nonhydrostatic Icosahedral Atmospheric Model (NICAM), a global cloud-system-resolving model. The evolution of the large-scale circulation and the storm-scale structure change was discussed in Part I. Both the mesoscale and system-scale processes in the life cycle of the simulated Isobel are documented in this paper. In the preconditioned favorable environment over the Java Sea, mesoscale convective vortices (model MCVs) developed in the mesoscale convective systems (MCSs) and convective towers with cyclonic potential vorticity (PV) anomalies throughout the troposphere [model vortical hot towers (VHTs)] appeared in the model MCVs. Multiple model VHTs strengthened cyclonic PV in the interior of the model MCV and led to the formation of an upright monolithic PV core at the center of the concentric MCV (primary vortex enhancement). As the monolithic PV core with a warm core developed near the circulation center, the intensification and the increase in horizontal size of the cyclonic PV were enhanced through the system-scale intensification (SSI) process (the secondary vortex enhancement), leading to the genesis of Isobel over the Timor Sea. The SSI process can be well explained by the balanced dynamics. After its genesis, the subsequent evolution of the simulated Isobel was controlled by both the external influence and the internal dynamics. Under the unfavorable environmental conditions, the development of asymmetric structure reduced the axisymmetric diabatic heating in the inner core and the SSI process became ineffective and the storm weakened. Later on, as the eyewall reformed as a result of the axisymmetrization of an inward-propagating outer spiral rainband, the SSI process became effective again, leading to the reintensification of Isobel. Therefore, the large-scale environmental flow provided the precondition for the genesis of Isobel and the triggering mechanism for subsequent storm-scale structure change as discussed in Part I. The system-scale and mesoscale processes, such as the evolution of MCVs and merging VHTs, were responsible for the genesis, while the eyewall processes were critical to the storm intensity change through the SSI process. © 2010 American Meteorological Society."
"14042645700;57216596414;36198188600;35517567400;","Conditioning stochastic rainfall replicates on remote sensing data",2009,"10.1109/TGRS.2009.2016413","https://www.scopus.com/inward/record.uri?eid=2-s2.0-67949108035&doi=10.1109%2fTGRS.2009.2016413&partnerID=40&md5=f0ff235a81a2e6a06a7bcd52ba34ae72","Temporally and spatially variable rainfall replicates are frequently required in hydrologic applications of ensemble forecasting and data assimilation. Ensemble methods can be expected to work better when the rainfall replicates more closely resemble observed storms. In particular, the replicates should capture the intermittency and variability that are dominant features of rainfall events. In this paper, we present a new probabilistic procedure for generating realistic rainfall replicates that are constrained by (or conditioned on) remote sensing measurements. The procedure uses remotely sensed cloud top temperatures to identify potentially rainy regions. The cloud top temperatures are obtained from visible/infrared instruments in geostationary orbit. A multipoint geostatistical algorithm generates areas of nonzero rain (rain clusters) within each cloudy region. This algorithm relies on statistics derived from ground-based weather radar [National Operational Weather Radar (NOWRAD)] data. A truncated multiplicative cascade generates rain rates within each rain cluster. A computational experiment based on summer 2004 data from the Central U.S. indicates that the rainfall replicates simulated by the procedure are visually and statistically similar to individual NOWRAD images and to a large ensemble of NOWRAD images collected throughout the summer simulation period. © 2006 IEEE."
"35572026100;7006095466;57203012011;55578808274;","Wavelet analysis of simulated tropical convective cloud systems. Part I: Basic analysis",2001,"10.1175/1520-0469(2001)058<0850:WAOSTC>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0035870803&doi=10.1175%2f1520-0469%282001%29058%3c0850%3aWAOSTC%3e2.0.CO%3b2&partnerID=40&md5=bc8f82f28589a952d532762dbacb82d2","A wavelet analysis of a three-dimensional 7-day explicit simulation of the tropical cloud systems in the Global Atmosphere Research Programme (GARP) Atlantic Tropical Experiment Phase III is performed. Three physically distinct regimes (squall line, nonsquall cloud cluster, and scattered convection) in a doubly periodic domain are analyzed using discrete Meyer wavelets. These wavelets are complete and facilitate the inversion of the decomposed modes. The full wavelet spectra well characterize the spatial localization of each physical variable, in particular, the vertical velocity and the condensate fields. The probability distribution of the wavelet coefficients is non-Gaussian despite the horizontal winds, the temperature, and humidity being closely Gaussian in physical space. This demonstrates the effectiveness of the wavelet basis for analyzing cloud system organization. The full wavelet spectrum also selects a preferred spatial orientation of the convective organization in physical space. A pseudospectrum is defined by taking the maximum absolute value of the wavelet coefficients for a given horizontal wavenumber vector as the spectrum coefficient. Unlike the conventional spectrum, this pseudospectrum objectively selects the observed convective-scale and mesoscale structure characteristic of observed mesoscale convective systems. The results demonstrate the broad utility of discrete Meyer wavelet analysis for objectively characterizing the structure and organization of multiscale convective cloud systems in an objective way."
"7004496942;7004091561;23568389400;23092832200;6506396422;6602635781;8409641400;8881295900;6603614013;7003451494;","A framework for expanding aqueous chemistry in the Community Multiscale Air Quality (CMAQ) model version 5.1",2017,"10.5194/gmd-10-1587-2017","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85017541739&doi=10.5194%2fgmd-10-1587-2017&partnerID=40&md5=32cdd1ea2b0599a166f6f064fc327ba1","This paper describes the development and implementation of an extendable aqueous-phase chemistry option (AQCHEM-KMT(I)) for the Community Multiscale Air Quality (CMAQ) modeling system, version 5.1. Here, the Kinetic PreProcessor (KPP), version 2.2.3, is used to generate a Rosenbrock solver (Rodas3) to integrate the stiff system of ordinary differential equations (ODEs) that describe the mass transfer, chemical kinetics, and scavenging processes of CMAQ clouds. CMAQ's standard cloud chemistry module (AQCHEM) is structurally limited to the treatment of a simple chemical mechanism. This work advances our ability to test and implement more sophisticated aqueous chemical mechanisms in CMAQ and further investigate the impacts of microphysical parameters on cloud chemistry. Box model cloud chemistry simulations were performed to choose efficient solver and tolerance settings, evaluate the implementation of the KPP solver, and assess the direct impacts of alternative solver and kinetic mass transfer on predicted concentrations for a range of scenarios. Month-long CMAQ simulations for winter and summer periods over the US reveal the changes in model predictions due to these cloud module updates within the full chemical transport model. While monthly average CMAQ predictions are not drastically altered between AQCHEM and AQCHEM-KMT, hourly concentration differences can be significant. With added in-cloud secondary organic aerosol (SOA) formation from biogenic epoxides (AQCHEM-KMTI), normalized mean error and bias statistics are slightly improved for 2-methyltetrols and 2-methylglyceric acid at the Research Triangle Park measurement site in North Carolina during the Southern Oxidant and Aerosol Study (SOAS) period. The added in-cloud chemistry leads to a monthly average increase of 11-18% in <q>cloud</q> SOA at the surface in the eastern United States for June 2013. © 2017 The Author(s)."
"23991212200;7004479957;6507017020;","Restricting 32-128 km horizontal scales hardly affects the MJO in the Superparameterized Community Atmosphere Model v.3.0 but the number of cloud-resolving grid columns constrains vertical mixing",2014,"10.1002/2014MS000340","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84932199444&doi=10.1002%2f2014MS000340&partnerID=40&md5=4b5ba6f0720cd6fd63979db9a1efdea3","The effects of artificially restricting the 32-128 km horizontal scale regime on MJO dynamics in the Superparameterized Community Atmosphere Model v.3.0 have been explored through reducing the extent of its embedded cloud resolving model (CRM) arrays. Two and four-fold reductions in CRM extent (from 128 to 64 km and 32 km) produce statistical composite MJO signatures with spatial scale, zonal phase speed, and intrinsic wind-convection anomaly structure that are all remarkably similar to the standard SPCAM's MJO. This suggests that the physics of mesoscale convective organization on 32-128 km scales are not critical to MJO dynamics in SPCAM and that reducing CRM extent may be a viable strategy for 400% more computationally efficient analysis of superparameterized MJO dynamics. However several unexpected basic state responses caution that extreme CRM domain reduction can lead to systematic mean state issues in superparameterized models. We hypothesize that an artificial limit on the efficiency of vertical updraft mixing is set by the number of grid columns available for compensating subsidence in the embedded CRM arrays. This can lead to reduced moisture ventilation supporting too much liquid cloud and thus an overly strong cloud shortwave radiative forcing, particularly in regions of deep convection. Key Points Physics of MMF MJO are insensitive to near elimination of meso-beta-scale The efficiency of deep convective mixing in MMFs is limited by CRM extent 4x speedup of superparameterized models possible for MJO analysis © 2014. The Authors."
"7102061651;16030470600;","Larson's scaling laws, and the gravitational instability of clumpy discs at high redshift",2014,"10.1093/mnras/stu954","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84903124924&doi=10.1093%2fmnras%2fstu954&partnerID=40&md5=03c803663bdec0378d4c6b7659cda34d","Gravitational instabilities play a primary role in shaping the clumpy structure and powering the star formation activity of gas-rich high-redshift galaxies. Here, we analyse the stability of such systems, focusing on the size and mass ranges of unstable regions in the disc. Our analysis takes into account the mass-size and linewidth-size scaling relations observed in molecular gas, originally discovered by Larson. We show that such relations can have a strong impact on the size and mass of star-forming clumps, as well as on the stability properties of the disc at all observable scales, making the classical Toomre parameter a highly unreliable indicator of gravitational instability. For instance, a disc with Q = 1 can be far from marginal instability, while a disc with Q ≪ 1 can be marginally unstable. Our work raises an important caveat: if clumpy discs at high redshift have scale-dependent surface densities and velocity dispersions, as implied by the observed clump scaling relations, then we cannot thoroughly understand their stability and star formation properties unless we perform multiscale observations. This will soon be possible thanks to dedicated Atacama Large Millimeter/submillimeter Array surveys, which will explore the physical properties of supergiant molecular clouds at the peak of cosmic star formation and beyond. © 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society."
"6701776280;36742334400;7006784914;7004909806;","Impact of the GEM model simplified physics on extratropical singular vectors",2004,"10.1256/qj.03.208","https://www.scopus.com/inward/record.uri?eid=2-s2.0-8344235978&doi=10.1256%2fqj.03.208&partnerID=40&md5=a60c67de368d684cc2d2957e7f391d0a","A simplified physics package, containing parametrizations of vertical diffusion, subgrid-scale orographic drag, stratiform precipitation and convective precipitation, was built for the four-dimensional variational data assimilation system that is being developed for the Canadian Global Environmental Multiscale model. To validate this package and measure its impact on the behaviour of unstable disturbances, a series of singular vector experiments was conducted. In a control experiment with vertical diffusion only, a set of 45 extratropical singular vectors was generated for a northern hemisphere winter case, using the total energy norm and an optimization time interval of 48 hours. Subsequently, the remaining components of the simplified physics were activated one by one and their influence was measured by changes in the energy partition, energy growth and spatial distribution of singular vectors. Cross-propagation tests were also made, where singular vectors from one experiment were evolved with the tangent-linear model of another. Results show that the orographic drag reduces the growth of singular vectors while the moist physics enhance the growth and shifts the energy of singular vectors toward smaller scales. Integrations of the nonlinear model with full physics indicate that, for amplitudes typical of analysis increments, the evolution of extratropical singular vectors is well described by the linearized model although growth rates are reduced by nonlinearities. © Crown, 2004."
"7003776366;57202371999;55425142900;7201862174;6603261786;57203186957;","From sun to earth: Multiscale MHD simulations of space weather",2001,"10.1029/GM125p0169","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84993228980&doi=10.1029%2fGM125p0169&partnerID=40&md5=c9c443f0a19b365d3f7bad3f6f8393e0","There is an increasing need to develop physics-based, high performance models of the Sun-Earth system — from the solar surface to the Earth’s upper atmosphere — which can operate faster than real time and which can provide reliable predictions of the near Earth space environment based upon solar observations and upstream solar wind measurements. Taking advantage of the advent of massively parallel computers, sophisticated solution-adaptive techniques, and recent fundamental advances in basic numerical methods we have developed a high performance, multiscale MHD code capable of resolving many of the critical processes in the Sun-Earth system which range over more than 9 orders of magnitude. We report on the first comprehensive numerical simulation of a “synthetic” space weather event, starting with the generation of a CME and subsequently following this transient solar wind disturbance as it evolves into a magnetic cloud and travels through interplanetary space towards Earth where its interaction with the terrestrial magnetosphere-ionosphere system is also predicted as part of the simulation. © 2001 by the American Geophysical Union."
"7003498065;57201216925;6602931427;7202180152;6602378790;8869265800;55271575700;7401895830;","Impacts of different characterizations of large-scale background on simulated regional-scale ozone over the continental United States",2018,"10.5194/acp-18-3839-2018","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85043993412&doi=10.5194%2facp-18-3839-2018&partnerID=40&md5=3f46a30288cb51bf68c200aefbb52942","This study analyzes simulated regional-scale ozone burdens both near the surface and aloft, estimates process contributions to these burdens, and calculates the sensitivity of the simulated regional-scale ozone burden to several key model inputs with a particular emphasis on boundary conditions derived from hemispheric or global-scale models. The Community Multiscale Air Quality (CMAQ) model simulations supporting this analysis were performed over the continental US for the year 2010 within the context of the Air Quality Model Evaluation International Initiative (AQMEII) and Task Force on Hemispheric Transport of Air Pollution (TF-HTAP) activities. CMAQ process analysis (PA) results highlight the dominant role of horizontal and vertical advection on the ozone burden in the mid-to-upper troposphere and lower stratosphere. Vertical mixing, including mixing by convective clouds, couples fluctuations in free-tropospheric ozone to ozone in lower layers. Hypothetical bounding scenarios were performed to quantify the effects of emissions, boundary conditions, and ozone dry deposition on the simulated ozone burden. Analysis of these simulations confirms that the characterization of ozone outside the regional-scale modeling domain can have a profound impact on simulated regional-scale ozone. This was further investigated by using data from four hemispheric or global modeling systems (Chemistry - Integrated Forecasting Model (C-IFS), CMAQ extended for hemispheric applications (H-CMAQ), the Goddard Earth Observing System model coupled to chemistry (GEOS-Chem), and AM3) to derive alternate boundary conditions for the regional-scale CMAQ simulations. The regional-scale CMAQ simulations using these four different boundary conditions showed that the largest ozone abundance in the upper layers was simulated when using boundary conditions from GEOS-Chem, followed by the simulations using C-IFS, AM3, and H-CMAQ boundary conditions, consistent with the analysis of the ozone fields from the global models along the CMAQ boundaries. Using boundary conditions from AM3 yielded higher springtime ozone columns burdens in the middle and lower troposphere compared to boundary conditions from the other models. For surface ozone, the differences between the AM3-driven CMAQ simulations and the CMAQ simulations driven by other large-scale models are especially pronounced during spring and winter where they can reach more than 10ĝ€̄ppb for seasonal mean ozone mixing ratios and as much as 15ĝ€̄ppb for domain-averaged daily maximum 8ĝ€̄h average ozone on individual days. In contrast, the differences between the C-IFS-, GEOS-Chem-, and H-CMAQ-driven regional-scale CMAQ simulations are typically smaller. Comparing simulated surface ozone mixing ratios to observations and computing seasonal and regional model performance statistics revealed that boundary conditions can have a substantial impact on model performance. Further analysis showed that boundary conditions can affect model performance across the entire range of the observed distribution, although the impacts tend to be lower during summer and for the very highest observed percentiles. The results are discussed in the context of future model development and analysis opportunities. © Author(s) 2018."
"34876209700;7401895830;8721787200;26029601100;","Effects of below-cloud scavenging on the regional aerosol budget in East Asia",2012,"10.1016/j.atmosenv.2011.08.065","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84863997727&doi=10.1016%2fj.atmosenv.2011.08.065&partnerID=40&md5=b3146357340a5510cd2fe7bb7e057265","We examine the effects of below-cloud scavenging on regional aerosol simulations over East Asia using wet deposition fluxes observed at Acid Deposition Monitoring Network in East Asia (EANET) sites and the Community Multiscale Air Quality (CMAQ) model together with a new below-cloud-scavenging scheme. Typical air quality models, including CMAQ, assume below-cloud scavenging as a simple first-order process with a constant or simple form depending on rain intensity. The scheme used here accounts for the collection efficiency, terminal velocity of raindrops, raindrop-size distributions, and particle-size distributions, which are important factors affecting below-cloud scavenging. We conduct model simulations for spring 2001, including baseline and sensitivity simulations. Our analysis mainly focuses on May 2001 to rule out the effect of dust aerosols. Simulated wet deposition fluxes of SO 4 2-, NO 3 -, and NH 4 + by the new scheme are increased by 103, 16, and 108%, respectively, relative to the baseline simulation and show better agreement with observations. The effect of below-cloud scavenging on coarse particles is even greater, producing wet deposition fluxes two orders of magnitude higher than the baseline. The resulting changes in the model indicate the considerable impacts of below-cloud scavenging on regional aerosol simulations over East Asia, where both anthropogenic emissions and natural sources of aerosols are present throughout the year. An accurate wet scavenging simulation is critical to simulate the atmospheric burden and wet deposition fluxes of both fine-mode and coarse-mode aerosols over East Asia. © 2011 Elsevier Ltd."
"8631239200;6602572031;7202180152;7404179087;","Diagnostic analysis of ozone concentrations simulated by two regional-scale air quality models",2011,"10.1016/j.atmosenv.2011.08.011","https://www.scopus.com/inward/record.uri?eid=2-s2.0-80052271910&doi=10.1016%2fj.atmosenv.2011.08.011&partnerID=40&md5=bc07a2c9acd8e21103ea2cb82403128c","Since the Community Multiscale Air Quality modeling system (CMAQ) and the Weather Research and Forecasting with Chemistry model (WRF/Chem) use different approaches to simulate the interaction of meteorology and chemistry, this study compares the CMAQ and WRF/Chem air quality simulation results for a month-long retrospective study period (August 2006) over the eastern United States, including comparisons with data from several observation networks. To help improve the comparability of the two models, the 2005 Carbon Bond chemical mechanism (CB05) was implemented into WRF/Chem. In addition, the same emissions, initial and boundary conditions have been used in both models to inter-compare simulated ozone (O3) from the WRF-driven CMAQ and WRF/Chem models. Results reveal that ground-level O3 from both models is biased high, especially in the central South and Ohio River Valley; however, WRF/Chem predicts roughly 10% more O3 aloft (1000-2500m AGL) than CMAQ. Different model configurations due to the choice of land surface model (LSM), planetary boundary layer (PBL) physics scheme, and convective cloud parameterization contributed to the differences seen in simulated O3, but most important were the different treatments of the radiative effects of clouds by their respective photolysis schemes. © 2011."
"55574230568;36538539800;7405728922;6701756440;","Use of a process analysis tool for diagnostic study on fine particulate matter predictions in the U.S.-Part II: Analyses and sensitivity simulations",2011,"10.5094/APR.2011.008","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79952455381&doi=10.5094%2fAPR.2011.008&partnerID=40&md5=12522d222861387a734f2b8dbbcecfab","Following the Part I paper that describes an application of the U.S. EPA Models-3/Community Multiscale Air Quality (CMAQ) modeling system to the 1999 Southern Oxidants Study episode, this paper presents results from process analysis (PA) using the PA tool embedded in CMAQ and subsequent sensitivity simulations to estimate the impacts of major model uncertainties identified through PA. Aerosol processes and emissions are the most important production processes for PM2.5 and its secondary components, while horizontal and vertical transport and dry deposition contribute to their removal. Cloud processes can contribute the production of PM2.5 and SO4 2- and the removal of NO3 - and NH4 +. The model biases between observed and simulated concentrations of PM2.5 and its secondary inorganic components are found to correlate with aerosol processes and dry deposition at all sites from all networks and sometimes with emissions and cloud processes at some sites. Guided with PA results, specific uncertainties examined include the dry deposition of PM2.5 species and its precursors, the emissions of PM2.5 precursors, the cloud processes of SO4 2-, and the gas-phase oxidation of SO2. Adjusting the most influential processes/factors (i.e., emissions of NH3 and SO2, dry deposition velocity of HNO3, and gas-phase oxidation of SO2 by OH) is found to improve the model overall performance in terms of SO4 2-, NO3 -, and NH4 + predictions. © Author(s) 2011."
"6506837510;7007108728;7004484970;","Ice water content and precipitation rate as a function of equivalent radar reflectivity and temperature based on in situ observations",2006,"10.1029/2005JD006499","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33746471812&doi=10.1029%2f2005JD006499&partnerID=40&md5=20fe4efc729fce141eabfe75e0cf488c","Using ice particle spectra measured in stratiform ice clouds in midlatitude and Arctic regions, ice water content (IWC) and precipitation rate (Fm) retrieval algorithms as a function of temperature and radar reflectivity factor (Z) have been developed. These parameterizations were compared with (1) direct measurements of IWC using a Nevzorov probe, (2) precipitation retrieved using an X-band Doppler scanning radar and a Precipitation Occurrence Sensor System (POSS), (3) the Canadian Global Environmental Multiscale (GEM) and High-Resolution Model Application Project (HIMAP) models, and (4) derived IWC and precipitation from measured ice spectra during four field projects. The derived IWC and Fm from measured spectra have a correlation coefficient (r) better than 0.8. The IWC retrieved using the X-band scanning radar during the First Alliance Icing Research Studies (AIRS I) agreed with IWC measured using the Nevzorov Probe much better than conventional IWC retrieval schemes. The retrieved precipitation rate based on the new algorithm using the POSS reflectivity measurements during the Second Alliance Icing Research Study (AIRS II) project agreed reasonably well with the precipitation rates predicted by the GEM and HIMAP models. This study clearly demonstrated that conventional IWC-Ze relationships fail to replicate the IWC measured with Nevzorov probe. Furthermore, the Fm-Z relationship currently in use in the Canadian operational radar network appears to underestimate the ice precipitation rate. However, since there are some uncertainties in the direct measurements of IWC and no reliable direct measurements of precipitation, further studies are required to validate these parameterizations."
"8832722300;7005067383;6603518408;7801421023;","Neural network retrieval of cloud parameters of inhomogeneous clouds from multispectral and multiscale radiance data: Feasibility study",2004,"10.1029/2003JD004186","https://www.scopus.com/inward/record.uri?eid=2-s2.0-4444310688&doi=10.1029%2f2003JD004186&partnerID=40&md5=b2251ba17e07729b5d4b8ba78d1005d3","In this paper, we investigated the feasibility of retrieving cloud parameters of inhomogeneous and fractional clouds from simulated multispectral and multiscale radiometric data by using mapping neural networks. A radiometric database prepared for neural network training consists of area-averaged radiance data for two pixel scales, i.e., (1 km × 1 km) and (0.25 km × 0.25 km) pixels, respectively. The cloud parameter retrieval assumes a vertically uniform inhomogeneous and fractional cloud defined with 6 parameters, i.e., the mean and standard deviation of optical thickness, the mean and standard deviation of effective radius, the fractional cloud cover, and the cloud top temperature, all defined at a scale of cloud parameter retrieval. The retrieval procedure comprises two separate steps: the first one is relative to the angular interpolation and correction of radiance data (surface reflection and thermal emission contribution). The second step concerns the cloud parameter retrieval as such from interpolated and corrected radiance data. The input vector to the retrieval MNNs consists of 8 radiometric data in addition to a number of necessary ancillary data such as surface temperature and ground albedo. The 8 radiometric data are 5 area-averaged radiances over (1 km × 1 km) pixel and 3 standard deviations of radiance over (1 km × 1 km) pixel estimated from (0.25 km × 0.25 km) pixel radiances. After evaluating the performance of the neural networks trained for each step, we tested the whole retrieval procedure for three types of inhomogeneous and fractional clouds: flat-top bounded cascade clouds and flat-top and non-flat-top Gaussian process clouds. All the cloud parameters of these clouds can be retrieved with reasonable accuracy in spite of the fact that the mean and standard deviation of optical thickness of non-flat-top clouds exhibit some dispersion. The inclusion of (0.25 km × 0.25 km) pixel radiance data as input vector components improved significantly the performance of the cloud parameter retrieval. Finally, we analyzed the consequences of some simplifying assumptions on the retrieved cloud parameters, and discussed the perspectives of the cloud parameter retrieval based on the neural networks. Copyright 2004 by the American Geophysical Union."
"23091000900;6603734019;7007108728;","Verification of supercooled cloud water forecasts with in Situ aircraft measurements",2001,"10.1175/1520-0434(2001)016<0145:VOSCWF>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0035245859&doi=10.1175%2f1520-0434%282001%29016%3c0145%3aVOSCWF%3e2.0.CO%3b2&partnerID=40&md5=61d3c20a24d7ea554a33ee9b129678ca","In situ measurements of temperature (Ta). horizontal wind speed (V), dewpoint (Td), total water content (TWC), and cloud and supercooled cloud water (SCW) events, made during 50 flights from three research field programs, have been compared to forecasts made with the High Resolution Model Application Project version of the Global Environmental Multiscale model. The main purpose of the comparisons was to test the accuracy of the forecasts of cloud and SCW fields. The forecast accuracy for Ta, V, and Td agreed closely with the results from radiosonde-model validation experiments, implying that the aircraft-model validation methodology was equally feasible and, therefore, potentially applicable to SCW forecast verifications (which the radiosondes could not validate). The hit rate (HR), false alarm rate (FAR), and true skill statistic (TSS) for cloud forecasts were found to be 0.52, 0.30, and 0.22, respectively, when the model data were inferred at a horizontal resolution of 1.5 km (averaging scale of the aircraft data). The corresponding values for SCW forecasts were 0.37, 0.22, and 0.15, respectively. The HRs (FARs) for cloud and SCW events are sensitive to horizontal resolution and increase to 0.76 (0.50) and 0.66 (0.53), respectively, when a horizontal resolution of 100 km is used. The model TWC was found to agree poorly with aircraft measurements, with the model generally underestimating TWC. For cases when the forecasts and observations of cloud agreed, the SCW-forecast HR, FAR, and TSS were 0.63, 0.22, and 0.41, respectively, which implies that improvement in the model cloud fields would substantially improve the SCW forecast accuracy. The demonstrated comparison methodology will allow a quantitative comparison between different SCW and cloud algorithms. Such a comparison will provide insight into the strengths and weaknesses of these algorithms and will allow the development of more accurate cloud and SCW forecasts."
"57202787748;57200852160;36018820000;7202283802;57211832884;57208368433;57203829285;34875643000;","Cloud and cloud shadow detection using multilevel feature fused segmentation network",2018,"10.1109/LGRS.2018.2846802","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85049302168&doi=10.1109%2fLGRS.2018.2846802&partnerID=40&md5=40896f60c90838bae33d5ea6a9b579a3","Cloud and cloud shadow detection in remote sensing imagery is important for its wide range of applications. Traditionally, the detection is usually based on the manually designed thresholds from multiband, which is complicated and of multistage. To simplify the process of cloud and cloud shadow detection and improve the performance, we propose a multilevel feature fused segmentation network (MFFSNet), which can be trained end-to-end without any hand-tuned parameters. Specifically, a fully convolutional network is proposed for cloud and cloud shadow features learning. Then, we utilize a novel pyramid pooling module to extract contextual relation between cloud and shadow. Furthermore, a special multilevel feature fused structure is designed to combine semantic information with spatial information from different levels, so that we can better handle the multiscale objects and produce detailed segmentation boundaries. Experiments show that the MFFSNet outperforms the state-of-the-art methods and achieves high accuracies of 98.69% and 98.92% for cloud and cloud shadow detection. © 2004-2012 IEEE."
"35768178600;57053165400;7006069664;57203474131;","Prediction of rapid intensification of tropical cyclone Phailin over the Bay of Bengal using the HWRF modelling system",2017,"10.1002/qj.2956","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85015347637&doi=10.1002%2fqj.2956&partnerID=40&md5=a4c4e0607df7932f1782a2c2fe64a6b0","The study objective is to assess the impact of cloud-permitting resolution and improved representation of multiscale processes on the ability to predict rapid intensification (RI) and structure of Phailin (2013), one of the strongest tropical cyclones (TCs) over the Bay of Bengal. The state-of-the-art Hurricane Weather Research and Forecasting (HWRF) modelling system is used with two different configurations. The first configuration uses a static domain of 27 km grid size with a movable nested domain of 9 km grid size (hereafter H2D). The second configuration has an additional movable nested domain of 3 km grid size (known as H3D) to resolve meso- and vortex-scale features respectively. The results clearly show the ability of the H3D system at cloud-permitting resolution (3 km) in predicting the TC movement, intensity and structure. The storm-to-vortex scale interaction in H3D allowed for better prediction of large-scale wind flow, low-level wind asymmetry and PV tendency, and provided insight to improve track predictions. The vortex depth is another important factor and the shallow vortex in the H2D run interacted differently with the large-scale environment and resulted in large track and intensity errors. Substantial gains are noticed in RI and structure prediction, mainly due to better simulation of diabatic heating, strong inflow, and moisture distribution in H3D, where the intensity errors are ≤11 knots (5.6 m s−1) up to the 72 h forecast, and up to 40 knots (20.5 m s−1) in the H2D version. The upper-level warming is well resolved in the H3D as compared to the H2D run. In summary, this study highlights the need for considering multiscale interactions and improved physics along with high-resolution initialization to resolve convective processes in the vortex and to realistically predict track, structure, and intensity changes. © 2016 Royal Meteorological Society"
"57219220333;7006235116;6506647236;","Building a tropical-extratropical cloud band metbot",2012,"10.1175/MWR-D-12-00127.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84871911740&doi=10.1175%2fMWR-D-12-00127.1&partnerID=40&md5=853be19095f2ca5fc90b3e5560e80cc9","An automated cloud band identification procedure is developed that captures the meteorology of such events over southern Africa. This ""metbot"" is built upon a connected component labeling method that enables blob detection in variousatmospheric fields. Outgoing longwave radiation is used to flag candidate cloud band days by thresholding the data and requiring detected blobs to have sufficient latitudinal extent and exhibit positive tilt. The Laplacian operator is usedon gridded reanalysis variables to highlight other features of meteorological interest. The ability of this methodologytocapture the significant meteorology and rainfall of these synoptic systems is tested in a case study. Usefulness of the metbot in understanding event-to-event similarities of meteorological features is demonstrated, highlighting features previous studies have noted as key ingredients to cloud band development in the region. Moreover, this allows the presentation of a composite cloud band life cycle for southern Africa events. The potential of metbot to study multiscale interactions is discussed, emphasizing its key strength: the ability to retain details of extreme and infrequent events. It automatically builds a database that is ideal for research questions focused on the influence of intraseasonal to interannual variability processes on synoptic events. Application of the method to convergence zone studies and atmospheric river descriptions is suggested. In conclusion, a relation-building metbot can retain details that are often lost with object-based methods but are crucial in case studies. Capturing and summarizing these details may be necessary to developa deeper process-level understanding of multiscale interactions.©2012 American Meteorological Society."
"16309604700;7601492669;7401945370;9535769800;25647939800;7801685271;","Multiscale interactions in the life cycle of a tropical cyclone simulated in a global cloud-system-resolving model. Part I: Large-scale and storm-scale evolutions",2010,"10.1175/2010MWR3474.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-78651102299&doi=10.1175%2f2010MWR3474.1&partnerID=40&md5=763aebccbb39deb4d26698c845b7818a","The Nonhydrostatic Icosahedral Atmospheric Model (NICAM), a global cloud-system-resolving model, successfully simulated the life cycle of Tropical Storm Isobel that formed over the Timor Sea in the austral summer of 2006. The multiscale interactions in the life cycle of the simulated storm were analyzed in this study. The large-scale aspects that affected Isobel's life cycle are documented in this paper and the corresponding mesoscale processes are documented in a companion paper. The life cycle of Isobel was largely controlled by a Madden-Julian oscillation (MJO) event and the associated westerly wind burst (WWB). The MJO was found to have both positive and negative effects on the tropical cyclone intensity depending on the location of the storm relative to the WWB center associated with the MJO. The large-scale low-level convergence and high convective available potential energy (CAPE) downwind of the WWB center provided a favorable region to the cyclogenesis and intensification, whereas the strong large-scale stretching deformation field upwind of the WWB center may weaken the storm by exciting wavenumber-2 asymmetries in the eyewall and leading to the eyewall breakdown. Five stages are identified for the life cycle of the simulated Isobel: the initial eddy, intensifying, temporary weakening, reintensifying, and decaying stages. The initial eddy stage was featured by small-scale/mesoscale convective cyclonic vortices developed in the zonally elongated rainband organized in the preconditioned environment characterized by the WWB over the Java Sea associated with the onset of an MJO event over the East Indian Ocean. As the MJO propagated eastward and the cyclonic eddies moved southward into an environment with weak vertical shear and strong low-level cyclonic vorticity, a typical tropical cyclone structure developed over the Java Sea, namely the genesis of Isobel. Isobel experienced an eyewall breakdown and a temporary weakening when it was located upwind of the WWB center as the MJO propagated southeastward and reintensified as its eyewall reformed as a result of the axisymmetrization of an inward spiraling outer rainband that originally formed downwind of the WWB center. Finally Isobel decayed as it approached the northwest coast of Australia. © 2010 American Meteorological Society."
"6506192691;7005805931;","Comparison of magnetic field structures on different scales in and around the filamentary dark cloud GF 9",2006,"10.1086/507454","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33845266745&doi=10.1086%2f507454&partnerID=40&md5=c32be9aa87c074dc0d88495b60221acc","New visible polarization data combined with existing IR and FIR polarization data are used to study how the magnetic field threading the filamentary molecular cloud GF 9 connects to larger structures in its general environment. When visible and NIR polarization data are combined, no evidence is found for a plateau in the polarization above extinction AV ≈ 1.3, as seen in dark clouds in Taurus. This lack of saturation effect suggests that even in the denser parts of GF 9 magnetic fields can be probed. The visible polarization is smooth and has a well-defined orientation. In the core region, the IR and FIR data are also well defined, but each with a different direction. A multiscale analysis of the magnetic field shows that on the scale of a few times the mean radial dimension of the molecular cloud, it is as if the magnetic field were ""blind"" to the spatial distribution of the filaments, while on smaller scales in the core region, multiwavelength polarimetry shows a rotation of the magnetic field lines in these denser phases. Finally, the Chandrasekhar and Fermi method is used to evaluate the magnetic field strength, indicating that the core region is approximately magnetically critical. A global interpretation suggests that in the core region an original poloidal field could have been twisted by a rotating elongated (core+envelope) structure. There is no evidence for turbulence, and ambipolar diffusion does not seem to be effective at the present time. © 2006. The American Astronomical Society. All rights reserved."
"6603333885;7005626683;7101959253;6701346974;","Evaluation of the multiscale modeling framework using data from the Atmospheric Radiation Measurement Program",2006,"10.1175/JCLI3699.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33744465029&doi=10.1175%2fJCLI3699.1&partnerID=40&md5=de245e7cb213f19db886c8952a18057c","In a recently developed approach to climate modeling, called the multiscale modeling framework (MMF), a two-dimensional cloud-resolving model (CRM) is embedded into each grid column of the Community Atmospheric Model (CAM), replacing traditional cloud and radiation parameterizations. This study presents an evaluation of the MMF through a comparison of its output with the output from the CAM and with data from two observational sites operated by the Atmospheric Radiation Measurement Program, one at the Southern Great Plains (SGP) in Oklahoma and one at the island of Nauru in the tropical western Pacific (TWP) region. Two sets of one-year-long simulations are considered: one using climatological sea surface temperatures (SSTs) and another using 1999 SST. Each set includes a run with the MMF as well as a CAM run with traditional or standard cloud and radiation treatments. Time series of cloud fraction, precipitation intensity, and downwelling solar radiation flux at the surface are analyzed. For the TWP site, the distributions of these variables from the MMF run are shown to be more consistent with observation than those from the CAM run. This change is attributed to the improved representation of convective clouds in the MMF compared to the conventional climate model. For the SGP, the MMF shows little to no improvement in predicting the same quantities. Possible causes of this lack of improvement are discussed. © 2006 American Meteorological Society."
"36987319800;57203054708;","Preliminary tests of multiscale modeling with a two-dimensional framework: Sensitivity to coupling methods",2005,"10.1175/MWR-2878.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-17044422131&doi=10.1175%2fMWR-2878.1&partnerID=40&md5=eeaf0c95ddc486c84bedb9c35883f4ed","Preliminary tests of the multiscale modeling approach, also known as the cloud-resolving convective parameterization, or superparameterization, are performed using an idealized framework. In this approach, a two-dimensional cloud-system resolving model (CSRM) is embedded within each vertical column of a general circulation model (GCM) replacing conventional cloud parameterization. The purpose of this study is to investigate the coupling between the GCM and CSRMs and suggest a revised method of coupling that abandons the cyclic lateral boundary condition for each CSRM used in the original cloud-resolving convective parameterization. In this way, the CSRM extends into neighboring GCM grid boxes while sharing approximately the same mass fluxes with the GCM at the borders of the grid boxes. With the original and revised methods of coupling, numerical simulations of the evolution of cloud systems are conducted using a two-dimensional model that couples CSRMs with a lower-resolution version of the CSRM with no physics [large-scale dynamics model (LSDM)]. The results with the revised method show that cloud systems can propagate from one LSDM grid column to the next as expected. Comparisons with a straightforward application of a single CSRM to the entire domain (CONTROL) show that the biases of the large-scale thermodynamic fields simulated by the coupled model are significantly smaller with the revised method. The results also show that the biases are near the smallest when the velocity fields of the LSDM and CSRM are nudged to each other with the time scale of a few hours and the thermodynamic field of the LSDM is instantaneously updated at each time step with the domain-averaged CSRM field. © 2005 American Meteorological Society."
"7003506951;55574210405;","Multiscale large eddy states in weakly stratified planetary boundary layers",1990,"10.1175/1520-0469(1990)047<0414:MLESIW>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0025625235&doi=10.1175%2f1520-0469%281990%29047%3c0414%3aMLESIW%3e2.0.CO%3b2&partnerID=40&md5=69cd469ad44059cc4c1826d4ddfe0fee","We discuss observations of two classes of two-dimensional large eddy states in weakly stratified atmospheric boundary layers. One class is characterized by large eddies with a single horizontal scale. The other contains multiscale large eddies, with horizontal wavelengths on the order of the boundary layer depth (as generally supported by spectra), coexisting with scales that are several times this depth (as generally seen in cloud street patterns). We develop nonlinear, coupled evolution equations that govern the temporal evolution of a set of three isolated disturbances of initial eigenmode form in a general unstable flow. These equations model both wave/wave and wave/mean flow interactions. They imply that relatively fast growing instabilities to an unstable mean state are themselves unstable. We suggest that the determining factor in selecting a large eddy state in the boundary layer is the presence or absence of sources of waves to the boundary layer that complement the dynamically or convectively driven boundary layer roll vortices. -from Authors"
"6603262263;7003498065;6603427849;14322460000;7202180152;7404179087;","Impact of inherent meteorology uncertainty on air quality model predictions",2015,"10.1002/2015JD023674","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84958787044&doi=10.1002%2f2015JD023674&partnerID=40&md5=6fb9deeb7c2cf4d7f8c6cc655997405f","It is well established that there are a number of different classifications and sources of uncertainties in environmental modeling systems. Air quality models rely on two key inputs, namely, meteorology and emissions. When using air quality models for decision making, it is important to understand how uncertainties in these inputs affect the simulated concentrations. Ensembles are one method to explore how uncertainty in meteorology affects air pollution concentrations. Most studies explore this uncertainty by running different meteorological models or the same model with different physics options and in some cases combinations of different meteorological and air quality models. While these have been shown to be useful techniques in some cases, we present a technique that leverages the initial condition perturbations of a weather forecast ensemble, namely, the Short-Range Ensemble Forecast system to drive the four-dimensional data assimilation in the Weather Research and Forecasting (WRF)-Community Multiscale Air Quality (CMAQ) model with a key focus being the response of ozone chemistry and transport. Results confirm that a sizable spread in WRF solutions, including common weather variables of temperature, wind, boundary layer depth, clouds, and radiation, can cause a relatively large range of ozone-mixing ratios. Pollutant transport can be altered by hundreds of kilometers over several days. Ozone-mixing ratios of the ensemble can vary asmuch as 10–20 ppb or 20–30% in areas that typically have higher pollution levels. © 2015. American Geophysical Union. All rights reserved."
"6508333712;24398842400;","Spatial and temporal variability of clouds and precipitation over Germany: Multiscale simulations across the ""gray zone""",2015,"10.5194/acp-15-12361-2015","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84946811422&doi=10.5194%2facp-15-12361-2015&partnerID=40&md5=d63f646783aee90a635ea006f621ba45","This paper assesses the resolution dependance of clouds and precipitation over Germany by numerical simulations with the COnsortium for Small-scale MOdeling (COSMO) model. Six intensive observation periods of the HOPE (HD(CP)2 Observational Prototype Experiment) measurement campaign conducted in spring 2013 and 1 summer day of the same year are simulated. By means of a series of grid-refinement resolution tests (horizontal grid spacing 2.8, 1 km, 500, and 250 m), the applicability of the COSMO model to represent real weather events in the gray zone, i.e., the scale ranging between the mesoscale limit (no turbulence resolved) and the large-eddy simulation limit (energy-containing turbulence resolved), is tested. To the authors' knowledge, this paper presents the first non-idealized COSMO simulations in the peer-reviewed literature at the 250-500 m scale. It is found that the kinetic energy spectra derived from model output show the expected -5/3 slope, as well as a dependency on model resolution, and that the effective resolution lies between 6 and 7 times the nominal resolution. Although the representation of a number of processes is enhanced with resolution (e.g., boundary-layer thermals, low-level convergence zones, gravity waves), their influence on the temporal evolution of precipitation is rather weak. However, rain intensities vary with resolution, leading to differences in the total rain amount of up to +48 %. Furthermore, the location of rain is similar for the springtime cases with moderate and strong synoptic forcing, whereas significant differences are obtained for the summertime case with air mass convection. Domain-averaged liquid water paths and cloud condensate profiles are used to analyze the temporal and spatial variability of the simulated clouds. Finally, probability density functions of convection-related parameters are analyzed to investigate their dependance on model resolution and their impact on cloud formation and subsequent precipitation. © Author(s) 2015."
"57203983376;7103201242;7102609908;15726586900;","Observations of a super cloud cluster accompanied by synoptic-scale Eastward-propagating precipitating systems over the Indian ocean",2010,"10.1175/2009JAS3151.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77955584534&doi=10.1175%2f2009JAS3151.1&partnerID=40&md5=3ffe3fe50c285dd5e522817bf4782ee3","The multiscale structure of a super cloud cluster (SCC) over the equatorial Indian Ocean, observed in November and December 2006, was investigated using data from satellite microwave sensors and surfacebased radars. The smaller-scale structure of this SCC was marked by a complicated relationship between rainfall systems and upper-tropospheric cloud shields, which moved eastward and westward, respectively, with a cycle of 2-4 days. In the analyses, attention was given to the structure of slow eastward-propagating (5-11 m s-1) precipitating systems and related synoptic-scale (~2000 km) disturbances. A case study of one of the systems revealed that it consisted of several lines of convective cells with a depth that was usually shallower than 10 km unless the cells encountered the westward-moving cloud shields. The environment of the convective lines was characterized by persistent unstable conditions with an increase of the westerly flow in the lower troposphere, suggesting the existence of a synoptic-scale upward motion. Composite analyses revealed that each rainfall system formed in a region of zonal flow convergence near the surface and divergence near 300 hPa. The vertical temperature structure tilted westward with height below this pressure level and eastward aloft, similar to that of a convectively coupled Kelvin wave. These results suggest that a SCC involves a group of synoptic-scale shallow waves propagating eastward. An additional analysis over the western Pacific also showed the predominance of eastward propagation in a SCC, demonstrating the advantage of satellite microwave sensors over infrared ones in monitoring the multiscale structure of tropical convection. © 2010 American Meteorological Society."
"10739428400;56887449400;6508011388;10739706100;55475208900;24725566100;34869082100;57203029613;","Models for gas/particle partitioning, transformation and air/water surface exchange of PCBs and PCDD/Fs in CMAQ",2007,"10.1016/j.atmosenv.2007.08.009","https://www.scopus.com/inward/record.uri?eid=2-s2.0-45449092473&doi=10.1016%2fj.atmosenv.2007.08.009&partnerID=40&md5=2a7a94450aaf97c51f9c264d11fcbc79","We have added the capability to simulate polychlorinated biphenyls (PCBs) and polychlorinated dibenzo [p] dioxins and polychlorinated dibenzo-furans (PCDD/Fs) to the Community Multiscale Air Quality (CMAQ) modeling system, thus taking advantage of the latter's capability to simulate atmospheric advection, diffusion, gas-phase chemistry, cloud/precipitation, and aerosol processes. The modifications reported here include the addition to the CMAQ system of two gas/particle partitioning models options: the Junge-Pankow adsorption model and the KOA absorption model, as well as chemical transformations and atmosphere/water surface exchange processes for these semi-volatile organics. Simulations for the purpose of model testing and validation were conducted for the years 2000 and 2002 on a domain covering most of North America. Both partitioning models give reasonable results when compared with available measurements. The model predictions of deposition and air concentrations also agree well with measurements. The modeling results also indicate that the long-range transport is important and anthropogenic emissions of PCBs and PCDD/Fs are dominant although surface exchange of PCBs may be important for some clean locations. © 2007 Elsevier Ltd. All rights reserved."
"35569334500;7402935899;36636962400;7404896077;","Multiscale magnetic fields in star-forming regions: Interferometric polarimetry of the MMS 6 core of OMC-3",2005,"10.1086/430127","https://www.scopus.com/inward/record.uri?eid=2-s2.0-23844504741&doi=10.1086%2f430127&partnerID=40&md5=ab504af7d5d5e4aa822361237aac168d","We present the first interferometric observations of linearly polarized emission toward the OMC-3 region of the Orion A cloud. We have observed the MMS 6 protostellar core at 1.3 mm with the Berkeley-Illinois-Maryland Association (BIMA) array, achieving a resolution of 4″.3 × 3″.0. We find that the polarization angle measured changes systematically across the core, orienting along a dust extension to the northwest. The polarization angle is oriented similarly to the 850 and 350 μm polarized emission measured by the SCUBA and Hertz polarimeters. A polarization hole is detected, as is typical of polarized emission data toward cores. Since the BIMA data are insensitive to structure on spatial scales of >40″, the emission detected is dominated by the core and not the integral-shaped filament in which it is embedded. Observations of CO J = 2-1 reveal CO emission potentially associated with the core, but no outflow signature is detected. Utilizing the Chandrasekhar-Fermi method, we have used the dispersion in the polarization vectors to estimate a field strength of 640 μG in the plane of the sky, assuming a corrective Q-factor of 0.5. Applying the recent measurement of the inclination of the field to the line of sight (Houde et al.), a total field strength of 680 μ,G is derived. Despite highly nonthermal line widths, the kinetic energy density is found to be insufficient to support this core against gravitational collapse. The magnetic energy density, when combined with the predominantly turbulent kinetic energy density, is comparable to the effects of gravity, but its value is highly dependent on the applied Q-factor to a degree that the core may be subcritical or supercritical. The preservation of the field geometry from large to small scales in this core is consistent with observations of a second protostellar core in a filamentary cloud in Orion B. © 2005. The American Astronomical Society. All rights reserved."
"56953627200;57191899408;55440970800;57202043934;55612861500;57193140976;","CDnet: CNN-Based Cloud Detection for Remote Sensing Imagery",2019,"10.1109/TGRS.2019.2904868","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85069770789&doi=10.1109%2fTGRS.2019.2904868&partnerID=40&md5=fd86d700e4fd56716a7676786040057b","Cloud detection is one of the important tasks for remote sensing image (RSI) preprocessing. In this paper, we utilize the thumbnail (i.e., preview image) of RSI, which contains the information of original multispectral or panchromatic imagery, to extract cloud mask efficiently. Compared with detection cloud mask from original RSI, it is more challenging to detect cloud mask using thumbnails due to the loss of resolution and spectrum information. To tackle this problem, we propose a cloud detection neural network (CDnet) with an encoder-decoder structure, a feature pyramid module (FPM), and a boundary refinement (BR) block. The FPM extracts the multiscale contextual information without the loss of resolution and coverage; the BR block refines object boundaries; and the encoder-decoder structure gradually recovers segmentation results with the same size as input image. Experimental results on the ZY-3 satellite thumbnails cloud cover validation data set and two other validation data sets (GF-1 WFV Cloud and Cloud Shadow Cover Validation Data and Landsat-8 Cloud Cover Assessment Validation Data) demonstrate that the proposed method achieves accurate detection accuracy and outperforms several state-of-the-art methods. © 1980-2012 IEEE."
"55303091800;36460530900;6506625022;","Unmanned aerial vehicle (UAV)-based monitoring of a landslide: Gallenzerkogel landslide (Ybbs-Lower Austria) case study",2018,"10.1007/s10661-017-6402-8","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85039051004&doi=10.1007%2fs10661-017-6402-8&partnerID=40&md5=38ee97d90a629793f0e642495d343ceb","In the present study, UAV-based monitoring of the Gallenzerkogel landslide (Ybbs, Lower Austria) was carried out by three flight missions. High-resolution digital elevation models (DEMs), orthophotos, and density point clouds were generated from UAV-based aerial photos via structure-from-motion (SfM). According to ground control points (GCPs), an average of 4 cm root mean square error (RMSE) was found for all models. In addition, light detection and ranging (LIDAR) data from 2009, representing the prefailure topography, was utilized as a digital terrain model (DTM) and digital surface model (DSM). First, the DEM of difference (DoD) between the first UAV flight data and the LIDAR-DTM was determined and according to the generated DoD deformation map, an elevation difference of between − 6.6 and 2 m was found. Over the landslide area, a total of 4380.1 m3 of slope material had been eroded, while 297.4 m3 of the material had accumulated within the most active part of the slope. In addition, 688.3 m3 of the total eroded material had belonged to the road destroyed by the landslide. Because of the vegetation surrounding the landslide area, the Multiscale Model-to-Model Cloud Comparison (M3C2) algorithm was then applied to compare the first and second UAV flight data. After eliminating both the distance uncertainty values of higher than 15 cm and the nonsignificant changes, the M3C2 distance obtained was between − 2.5 and 2.5 m. Moreover, the high-resolution orthophoto generated by the third flight allowed visual monitoring of the ongoing control/stabilization work in the area. © 2017, Springer International Publishing AG, part of Springer Nature."
"7202467963;36676931900;7501959001;","Integrating multisensor satellite data merging and image reconstruction in support of machine learning for better water quality management",2017,"10.1016/j.jenvman.2017.06.045","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85021280402&doi=10.1016%2fj.jenvman.2017.06.045&partnerID=40&md5=435861d3218065c139a0316bb38199e5","Monitoring water quality changes in lakes, reservoirs, estuaries, and coastal waters is critical in response to the needs for sustainable development. This study develops a remote sensing-based multiscale modeling system by integrating multi-sensor satellite data merging and image reconstruction algorithms in support of feature extraction with machine learning leading to automate continuous water quality monitoring in environmentally sensitive regions. This new Earth observation platform, termed “cross-mission data merging and image reconstruction with machine learning” (CDMIM), is capable of merging multiple satellite imageries to provide daily water quality monitoring through a series of image processing, enhancement, reconstruction, and data mining/machine learning techniques. Two existing key algorithms, including Spectral Information Adaptation and Synthesis Scheme (SIASS) and SMart Information Reconstruction (SMIR), are highlighted to support feature extraction and content-based mapping. Whereas SIASS can support various data merging efforts to merge images collected from cross-mission satellite sensors, SMIR can overcome data gaps by reconstructing the information of value-missing pixels due to impacts such as cloud obstruction. Practical implementation of CDMIM was assessed by predicting the water quality over seasons in terms of the concentrations of nutrients and chlorophyll-a, as well as water clarity in Lake Nicaragua, providing synergistic efforts to better monitor the aquatic environment and offer insightful lake watershed management strategies. © 2017 Elsevier Ltd"
"14920137300;","A strategy for representing the effects of convective momentum transport in multiscale models: Evaluation using a new superparameterized version of the Weather Research and Forecast model (SP-WRF)",2015,"10.1002/2014MS000417","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85027921791&doi=10.1002%2f2014MS000417&partnerID=40&md5=d235b4b8f88330cd617b47890364ba66","This paper describes a general method for the treatment of convective momentum transport (CMT) in large-scale dynamical solvers that use a cyclic, two-dimensional (2-D) cloud-resolving model (CRM) as a ""superparameterization"" of convective-system-scale processes. The approach is similar in concept to traditional parameterizations of CMT, but with the distinction that both the scalar transport and diagnostic pressure gradient force are calculated using information provided by the 2-D CRM. No assumptions are therefore made concerning the role of convection-induced pressure gradient forces in producing up or down-gradient CMT. The proposed method is evaluated using a new superparameterized version of the Weather Research and Forecast model (SP-WRF) that is described herein for the first time. Results show that the net effect of the formulation is to modestly reduce the overall strength of the large-scale circulation, via ""cumulus friction."" This statement holds true for idealized simulations of two types of mesoscale convective systems, a squall line, and a tropical cyclone, in addition to real-world global simulations of seasonal (1 June to 31 August) climate. In the case of the latter, inclusion of the formulation is found to improve the depiction of key synoptic modes of tropical wave variability, in addition to some aspects of the simulated time-mean climate. The choice of CRM orientation is also found to importantly affect the simulated time-mean climate, apparently due to changes in the explicit representation of wide-spread shallow convective regions. © 2015. The Authors."
"6701333444;6506545080;37018824600;55272477500;8859530100;36076994600;37116849700;9132948500;7402934750;56611366900;7409074131;7401936984;7203034123;55745955800;6701346974;","RACORO continental boundary layer cloud investigations: 1. case study development and ensemble large-scale forcings",2015,"10.1002/2014JD022713","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84955749226&doi=10.1002%2f2014JD022713&partnerID=40&md5=391deaa6ab07bec4a01d78d84d8e4998","Observation-based modeling case studies of continental boundary layer clouds have been developed to study cloudy boundary layers, aerosol influences upon them, and their representation in cloud- and global-scale models. Three 60 h case study periods span the temporal evolution of cumulus, stratiform, and drizzling boundary layer cloud systems, representing mixed and transitional states rather than idealized or canonical cases. Based on in situ measurements from the Routine AAF (Atmospheric Radiation Measurement (ARM) Aerial Facility) CLOWD (Clouds with Low Optical Water Depth) Optical Radiative Observations (RACORO) field campaign and remote sensing observations, the cases are designed with a modular configuration to simplify use in large-eddy simulations (LES) and single-column models. Aircraft measurements of aerosol number size distribution are fit to lognormal functions for concise representation in models. Values of the aerosol hygroscopicity parameter, κ, are derived from observations to be ~0.10, which are lower than the 0.3 typical over continents and suggestive of a large aerosol organic fraction. Ensemble large-scale forcing data sets are derived from the ARM variational analysis, European Centre for Medium-Range Weather Forecasts, and a multiscale data assimilation system. The forcings are assessed through comparison of measured bulk atmospheric and cloud properties to those computed in “trial” large-eddy simulations, where more efficient run times are enabled through modest reductions in grid resolution and domain size compared to the full-sized LES grid. Simulations capture many of the general features observed, but the state-of-the-art forcings were limited at representing details of cloud onset, and tight gradients and high-resolution transients of importance. Methods for improving the initial conditions and forcings are discussed. The cases developed are available to the general modeling community for studying continental boundary clouds. © 2015. American Geophysical Union. All Rights Reserved."
"8977001000;7403282069;","Diurnal variability of low clouds in the Southeast Pacific simulated by a multiscale modeling framework model",2013,"10.1002/jgrd.50683","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84885143603&doi=10.1002%2fjgrd.50683&partnerID=40&md5=881001c3915b7e08679be279b7545fe6","This study analyzes the diurnal variations of austral-spring stratocumulus clouds in the Southeast Pacific and their physical mechanisms from a global multiscale modeling framework (MMF) simulation. This MMF contains an advanced third-order turbulence closure in its cloud-resolving model component, helping it to realistically simulate boundary layer turbulence and low-level clouds. The main finding is that the MMF simulation can reproduce the spatial pattern of the diurnal variations of low clouds within the region, with the day-night cloud fraction (CF) differences ranging from 0.10 at 30° off the shore to 0.40 near the shore. The diurnal phases and ranges of simulated liquid water path, CF, and surface cloud radiative effects agree well with available observations. The maximum CF occurs in the early morning and the minimum in the late afternoon over the open ocean. However, near the shore, the maximum/minimum CF anomalies are more variable. The spatial variability of the diurnal variations is attributed to the modulation of solar-forced variation by the orographically induced circulation. The solar radiation makes the lower cloud layer dissipated during the day, and clouds recover first there in the early evening, with the upper cloud layer changing relatively less in cloudiness. The southwestward propagating upsidence wave that is related to the orographical forcing modulates the CF anomalies near the shore. The orographically induced subsidence, however, extends too deeply into the boundary layer because of the model's unrealistically smooth topography, and it dissipates rather than enhances the stratocumulus near the shore between the late night and the following noon. © 2013. Her Majesty the Queen in Right of Canada. American Geophysical Union."
"6603627233;","High-resolution simulations of high-impact weather systems using the cloud-resolving model on the earth simulator",2008,"10.1007/978-0-387-49791-4_9","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84886097882&doi=10.1007%2f978-0-387-49791-4_9&partnerID=40&md5=cb89dbdffd3376bf38ce1e115d95f575","High-impact weather systems occasionally cause huge disasters to human society owing to heavy rainfall and/or violent wind. They consist of cumulonimbus clouds and usually have a multiscale structure. High-resolution simulations within a large domain are necessary for quantitatively accurate prediction of the weather systems and prevention/reduction of disasters. For the simulations, we have been developing a cloud-resolving model named the Cloud Resolving Storm Simulator (CReSS). The model is designed for a parallel computer and was optimized for the Earth Simulator in the present study. The purpose of the present research is highresolution simulations of high-impact weather systems in a large calculation domain with resolving individual cumulonimbus clouds using the CReSS model on the Earth Simulator. Characteristic high-impact weather systems in East Asia are the Baiu front, typhoons, and winter snowstorms. The present chapter describes simulations of these significant weather systems. We have chosen for the case study of the Baiu front the Niigata-Fukushima heavy rainfall event on July 13, 2004. Typhoons for simulations are T0418, which caused a huge disaster due to strong wind, and T0423, which caused severe flood over the western Japan in 2004. Snowstorms were studied by an idealized numerical experiment as well as by a simulation of cold air outbreak over the Sea of Japan. These experiments clarified both the overall structures of weather systems and individual clouds. The high-resolution simulations resolving individual clouds permit a more quantitative prediction of precipitation. They contribute to accurate prediction of wind and precipitation and to reduction of disasters caused by high-impact weather systems. © 2008 Springer-Verlag New York."
"57207486814;12645767500;8067118800;7202899330;56162305900;","An investigation of microphysics and subgrid-scale variability in warm-rain clouds using the A-train observations and a multiscale modeling framework",2017,"10.1002/2016JD026404","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85027727674&doi=10.1002%2f2016JD026404&partnerID=40&md5=2247c11414064f563e4d6c4c4ace1b38","A common problem in climate models is that they are likely to produce rain at a faster rate than is observed and therefore produce too much light rain (e.g., drizzle). Interestingly, the Pacific Northwest National Laboratory (PNNL) multiscale modeling framework (MMF), whose warm-rain formation process is more realistic than other global models, has the opposite problem: the rain formation process in PNNL-MMF is less efficient than the real world. To better understand the microphysical processes in warm cloud, this study documents the model biases in PNNL-MMF and evaluates warm cloud properties, subgrid variability, and microphysics, using A-Train satellite observations to identify sources of model biases in PNNL-MMF. Like other models PNNL-MMF underpredicts the warm cloud fraction with compensating large optical depths. Associated with these compensating errors in cloudiness are compensating errors in the precipitation process. For a given liquid water path, clouds in the PNNL-MMF are less likely to produce rain than are real-world clouds. However, when the model does produce rain it is able to produce stronger precipitation than reality. As a result PNNL-MMF produces about the correct mean rain rate with an incorrect distribution of rates. The subgrid variability in PNNL-MMF is also tested, and results are fairly consistent with observations, suggesting that the possible sources of model biases are likely to be due to errors in its microphysics or dynamics rather than errors in the subgrid-scale variability produced by the embedded cloud resolving model. © 2017. American Geophysical Union."
"7003908632;55082035300;12764954600;7006204597;","Assessment of the effects of acid-coated ice nuclei on the Arctic cloud microstructure, atmospheric dehydration, radiation and temperature during winter",2013,"10.1002/joc.3454","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873527043&doi=10.1002%2fjoc.3454&partnerID=40&md5=2070d764e1fd00f1eb84d54ca4fa5c46","Owing to the large-scale transport of pollution-derived aerosols from the mid-latitudes to the Arctic, most of the aerosols are coated with acidic sulfate during winter in the Arctic. Recent laboratory experiments have shown that acid coating on dust particles substantially reduces the ability of these particles to nucleate ice crystals. Simulations performed using the Limited Area version of the Global Multiscale Environmental Model (GEM-LAM) are used to assess the potential effect of acid-coated ice nuclei on the Arctic cloud and radiation processes during January and February 2007. Ice nucleation is treated using a new parameterization based on laboratory experiments of ice nucleation on sulphuric acid-coated and uncoated kaolinite particles. Results show that acid coating on dust particles has an important effect on cloud microstructure, atmospheric dehydration, radiation and temperature over the Central Arctic, which is the coldest part of the Arctic. Mid and upper ice clouds are optically thinner while low-level mixed-phase clouds are more frequent and persistent. These changes in the cloud microstructures affect the radiation at the top of the atmosphere with longwave negative cloud forcing values ranging between 0 and - 6 W m-2 over the region covered by the Arctic air mass. © 2012 Royal Meteorological Society."
"37121839900;8670222900;8618282100;7101691582;23486614500;7402132163;","Mechanisms responsible for the build-up of ozone over South East England during the August 2003 heatwave",2011,"10.1016/j.atmosenv.2011.04.035","https://www.scopus.com/inward/record.uri?eid=2-s2.0-80755153739&doi=10.1016%2fj.atmosenv.2011.04.035&partnerID=40&md5=58e5bf24c919a405d9f249f2a248e613","The Community Multiscale Air Quality (CMAQ) model is used in order to quantify reasons for the build-up of ozone over South East England during the August 2003 heatwave. Unlike previous studies, the effects of individual meteorological and chemical processes on the temporal evolution of the episode are assessed quantitatively in the present work. The performance of the modelling system was briefly evaluated. The modelling system was able to capture the evolution of the episode, with increasing ozone levels during the period 1-4 August 2003, and maximum values afterwards. Analysis of the results of the CMAQ model indicates that three mechanisms were mainly responsible for the episode: (i) horizontal transport from mainland Europe in the presence of a long-lived high-pressure system, (ii) convergence of westerly and easterly near-surface winds, and (iii) downward entrainment of ozone-rich air from residual layers in the free troposphere. The downward entrainment of ozone from residual layers in the morning is found to be key to enhancing ozone levels during the day. The relevance of this mechanism is supported by the good agreement of the model vertical ozone distribution with that derived from Light detection and ranging (Lidar) measurements. The process analysis of the rate of change of ozone concentration shows that both horizontal transport and vertical transport were equally important in explaining the variability of ozone. The contribution of chemical processes to the increase of ozone concentration as simulated by the modelling system is relatively small close to the surface. However, its contribution to the decrease of ozone concentration there becomes as important as that of meteorological processes. By investigating the role of separate meteorological and chemical mechanisms, this study hopes to add to the current understanding of the evolution of air pollution episode. © 2011 Elsevier Ltd."
"57193882808;","Comments on ""preliminary tests of multiscale modeling with a two-dimensional framework: Sensitivity to coupling methods""",2006,"10.1175/MWR3161.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33746925184&doi=10.1175%2fMWR3161.1&partnerID=40&md5=93eb7551978c30e8b11b72d577395537","In summary, in the test used in JA05, the original SP approach (GS99; G01; Grabowski 2004) performs substantially better than concluded by JA05. The key is the coupling between mesoscale and convective dynamics, which (for unclear reasons) was not captured in JA05's test of the original SP approach. The 3D results presented here (Figs. 4 and 5) suggest that the original approach is attractive for mesoscale models with a horizontal grid length in the range of 20-50 km (e.g., in regional climate models). In such a case, small-scale convective dynamics (albeit in 2D) are captured by the SP model, and 3D mesoscale dynamics are captured by the mesoscale model. The approach developed in JA05, on the other hand, seems better suited for large-scale models with a horizontal grid length of a few hundred kilometers, as in contemporary global climate models. In such a case, the mesoscale and convective dynamics have to be treated by SP models, and coherent propagation of cloud and mesoscale structures across the large-scale model grid is only possible in the approach proposed by JA05. In a nutshell, the test used in JA05 seems a poor choice for illustrating their approach. It would be more appropriate to use the idealized 2D Walker circulation test (Grabowski et al. 2000) as applied in G01. © 2006 American Meteorological Society."
"6603678039;6603944096;7201541138;","The H II region sharpless 170: A multiscale analysis of the Hα velocity field",1995,"10.1086/176484","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0007381718&doi=10.1086%2f176484&partnerID=40&md5=391f88df895420b0e714468bea84bdb9","A total of 12,695 Hα radial velocities were measured across the H II region Sh 170 using a Fabry-Perot camera. The mean VLSR of the ionized gas is -50.10 ± 0.08 km s-1 with a velocity dispersion of 8.70 ± 0.05 km s-1. Sh 170 has a blueshift of 6.4 km s-1 with respect to the associated molecular cloud. The nebula is density bounded on all visible sides, indicating that the H II region is seen in front of the molecular cloud. The velocity field can be explained as an expansion of the ionized gas away from the molecular cloud toward the observer. A north-south velocity gradient of 1.4 km s-1 pc is also observed. The locus of the less negative velocity (VLSR ≈ -45 km s-1) coincides with the molecular cloud's position. Several kinematical and morphological aspects of Sh 170 are in good agreement with the ""Champagne"" phase model. Sh 170 has a ∼2 pc cavity devoid of ionized gas approximately centered on the ionizing star which can be explained by the action of a stellar wind. The large number of velocity measurements allowed a systematic analysis of velocity fluctuations in Sh 170. The relation between centroid velocity dispersion σc and scale l was derived. The two-point autocorrelation (C) and structure (S) functions were used; these are reliable tools for the investigation of the statistical properties of fluctuating gas motions. It was found that velocity correlation occurs at scales smaller than 0.7 pc in Sh 170. The e-folding length of the autocorrelation function (the correlation length) is 0.03 ± 0.02 pc, and a power-law relation between S and scale was obtained: S(τ) ∝ τ0.8±0.1. An interpretation of these results in terms of turbulence is presented."
"36624257700;55924208000;","Ensemble superparameterization versus stochastic parameterization: A comparison of model uncertainty representation in tropical weather prediction",2017,"10.1002/2016MS000857","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85019839431&doi=10.1002%2f2016MS000857&partnerID=40&md5=10d8b2e2f842e95d3ef0b8d19e259edf","Stochastic schemes to represent model uncertainty in the European Centre for Medium-Range Weather Forecasts (ECMWF) ensemble prediction system has helped improve its probabilistic forecast skill over the past decade by both improving its reliability and reducing the ensemble mean error. The largest uncertainties in the model arise from the model physics parameterizations. In the tropics, the parameterization of moist convection presents a major challenge for the accurate prediction of weather and climate. Superparameterization is a promising alternative strategy for including the effects of moist convection through explicit turbulent fluxes calculated from a cloud-resolving model (CRM) embedded within a global climate model (GCM). In this paper, we compare the impact of initial random perturbations in embedded CRMs, within the ECMWF ensemble prediction system, with stochastically perturbed physical tendency (SPPT) scheme as a way to represent model uncertainty in medium-range tropical weather forecasts. We especially focus on forecasts of tropical convection and dynamics during MJO events in October–November 2011. These are well-studied events for MJO dynamics as they were also heavily observed during the DYNAMO field campaign. We show that a multiscale ensemble modeling approach helps improve forecasts of certain aspects of tropical convection during the MJO events, while it also tends to deteriorate certain large-scale dynamic fields with respect to stochastically perturbed physical tendencies approach that is used operationally at ECMWF. © 2017. The Authors."
"7101801476;7202772927;7401701196;7403577184;9249239700;7102718675;6701684534;6701845806;","Performance of the Goddard multiscale modeling framework with Goddard ice microphysical schemes",2016,"10.1002/2015MS000469","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84964447040&doi=10.1002%2f2015MS000469&partnerID=40&md5=eb3b61bb458c6ce4c94662e05a8e460c","The multiscale modeling framework (MMF), which replaces traditional cloud parameterizations with cloud-resolving models (CRMs) within a host atmospheric general circulation model (GCM), has become a new approach for climate modeling. The embedded CRMs make it possible to apply CRM-based cloud microphysics directly within a GCM. However, most such schemes have never been tested in a global environment for long-term climate simulation. The benefits of using an MMF to evaluate rigorously and improve microphysics schemes are here demonstrated. Four one-moment microphysical schemes are implemented into the Goddard MMF and their results validated against three CloudSat/CALIPSO cloud ice products and other satellite data. The new four-class (cloud ice, snow, graupel, and frozen drops/hail) ice scheme produces a better overall spatial distribution of cloud ice amount, total cloud fractions, net radiation, and total cloud radiative forcing than earlier three-class ice schemes, with biases within the observational uncertainties. Sensitivity experiments are conducted to examine the impact of recently upgraded microphysical processes on global hydrometeor distributions. Five processes dominate the global distributions of cloud ice and snow amount in long-term simulations: (1) allowing for ice supersaturation in the saturation adjustment, (2) three additional correction terms in the depositional growth of cloud ice to snow, (3) accounting for cloud ice fall speeds, (4) limiting cloud ice particle size, and (5) new size-mapping schemes for snow and graupel. Despite the cloud microphysics improvements, systematic errors associated with subgrid processes, cyclic lateral boundaries in the embedded CRMs, and momentum transport remain and will require future improvement. © 2015. The Authors."
"8688004400;6603263640;7004978125;57193882808;","Multiscale interactions in an idealized walker circulation: Mean circulation and intraseasonal variability",2014,"10.1175/JAS-D-13-018.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84896793832&doi=10.1175%2fJAS-D-13-018.1&partnerID=40&md5=83d5bd2c237bf99e32b34110b9b2883d","A high-resolution cloud-resolving model (CRM) simulation is developed here for a two-dimensional Walker circulation over a planetary-scale domain of 40 000km for an extended period of several hundred days. The Walker cell emerges as the time-averaged statistical steady state with a prescribed sinusoidal sea surface temperature (SST) pattern with a mean temperature of 301.15Kand a horizontal variation of 4K. The circulation exhibits intraseasonal variability on a time scale of about 20 days with quasi-periodic intensification of the circulation and broadening of the convective regime. This variability is closely tied to synoptic-scale systems associated with expansion and contraction of the Walker circulation. An index for the low-frequency variability is developed using an empirical orthogonal function (EOF) analysis and by regressing various dynamic fields on this index. The low-frequency oscillation has four main stages: a suppressed stage with strengthened midlevel circulation, an intensification phase, an active phase with strong upper-level circulation, and a weakening phase. Various physical processes occurring at these stages are discussed as well as the impact of organized convective systems on the large-scale flow. © 2014 American Meteorological Society."
"57196090238;8676866700;35739392600;","Flood forecasts based on multi-model ensemble precipitation forecasting using a coupled atmospheric-hydrological modeling system",2014,"10.1007/s11069-014-1204-6","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84939889584&doi=10.1007%2fs11069-014-1204-6&partnerID=40&md5=44f95a38209461834e03c160f4d6464c","The recent improvement of numerical weather prediction (NWP) models has a strong potential for extending the lead time of precipitation and subsequent flooding. However, uncertainties inherent in precipitation outputs from NWP models are propagated into hydrological forecasts and can also be magnified by the scaling process, contributing considerable uncertainties to flood forecasts. In order to address uncertainties in flood forecasting based on single-model precipitation forecasting, a coupled atmospheric-hydrological modeling system based on multi-model ensemble precipitation forecasting is implemented in a configuration for two episodes of intense precipitation affecting the Wangjiaba sub-region in Huaihe River Basin, China. The present study aimed at comparing high-resolution limited-area meteorological model Canadian regional mesoscale compressible community model (MC2) with the multiple linear regression integrated forecast (MLRF), covering short and medium range. The former is a single-model approach; while the latter one is based on NWP models [(MC2, global environmental multiscale model (GEM), T213L31 global spectral model (T213)] integrating by a multiple linear regression method. Both MC2 and MLRF are coupled with Chinese National Flood Forecasting System (NFFS), MC2-NFFS and MLRF-NFFS, to simulate the discharge of the Wangjiaba sub-basin. The evaluation of the flood forecasts is performed both from a meteorological perspective and in terms of discharge prediction. The encouraging results obtained in this study demonstrate that the coupled system based on multi-model ensemble precipitation forecasting has a promising potential of increasing discharge accuracy and modeling stability in terms of precipitation amount and timing, along with reducing uncertainties in flood forecasts and models. Moreover, the precipitation distribution of MC2 is more problematic in finer temporal and spatial scales, even for the high resolution simulation, which requests further research on storm-scale data assimilation, sub-grid-scale parameterization of clouds and other small-scale atmospheric dynamics. © 2014, Springer Science+Business Media Dordrecht."
"43961759100;7004433410;55667075800;36721587000;55832723000;57200790631;6603369413;35448188800;","Estimating the influence of lightning on upper tropospheric ozone using NLDN lightning data and CMAQ model",2013,"10.1016/j.atmosenv.2012.11.001","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84872386736&doi=10.1016%2fj.atmosenv.2012.11.001&partnerID=40&md5=2aa75cc5ee3f33a592602106dc0d7229","Lightning is a particularly significant NOx source in the middle and upper troposphere where it affects tropospheric chemistry and ozone. Because the version-4 Community Multiscale Air Quality Modeling System (CMAQ) does not account for NOx emission from lightning, it underpredicts NOx above the mixed layer. In this study, the National Lightning Detection Network™ (NLDN) lightning data are applied to the CMAQ model to simulate the influence of lightning-produced NOx (LNOx) on upper tropospheric NOx and subsequent ozone concentration. Using reasonable values for salient parameters (detection efficiency ~95%, cloud flash to ground flash ratio ~3, LNOx production rate ~500 mol N per flash), the NLDN ground flashes are converted into total lightning NOx amount and then vertically distributed on 39 CMAQ model layers according to a vertical-distribution profile of lightning N mass. This LNOx contributes 27% of the total NOx emission during 15 July ~7 September 2006. This additional NOx reduces the low-bias of simulated tropospheric O3 columns with respect to OMI tropospheric O3 columns from 10 to 5%. Although the model prediction of ozone in upper troposphere improves by ~20 ppbv due to lightning-produced NOx above the southeastern and eastern U.S.A., the improved ozone prediction is still ~20-25 ppbv lower than ozonesonde measurements. © 2012 Elsevier Ltd."
"12764954600;7003908632;7006204597;7003663305;","Modeling of the cloud and radiation processes observed during SHEBA",2011,"10.1016/j.atmosres.2011.05.018","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79960902135&doi=10.1016%2fj.atmosres.2011.05.018&partnerID=40&md5=540cf0f42335a0f134e8f1bfaa8980e1","Six microphysics schemes implemented in the climate version of the Environment Canada's Global Multiscale Environmental (GEM) model are used to simulate the cloud and radiation processes observed during Surface Heat Budget of the Arctic Ocean (SHEBA) field experiment. The simplest microphysics scheme (SUN) has one prognostic variable: the total cloud water content. The second microphysics scheme (MLO) has 12 prognostic variables. The four other microphysics schemes are modified versions of MLO. A new parameterization for heterogeneous ice nucleation based on laboratory experiments is included in these versions of MLO. One is for uncoated ice nuclei (ML-NAC) and another is for sulfuric acid coated ice nuclei (ML-AC). ML-AC and ML-NAC have been developed to distinguish non-polluted and polluted air masses, the latter being common over the Arctic during winter and spring. A sensitivity study, in which the dust concentration is reduced by a factor 5, is also performed to assess the sensitivity of the results to the dust concentration in ML-AC-test and ML-NAC-test.Results show that SUN, ML-AC and ML-AC-test reproduce quite well the downward longwave radiation and cloud radiative forcing during the cold season. The good results obtained with SUN are due to compensating errors. It overestimates cloud fraction and underestimates cloud liquid water path during winter. ML-AC and ML-AC-test reproduces quite well all these variables and their relationships. MLO, ML-NAC and ML-NAC-test underestimate the cloud liquid water path and cloud fraction during the cold season, which leads to an underestimation of the downward longwave radiation at surface. During summer, all versions of the model underestimate the downward shortwave radiation at surface. ML-AC and ML-NAC overestimate the total cloud water during the warm season, however, they reproduce relatively well the relationships between cloud radiative forcing and cloud microstructure, which is not the case for the most simple scheme SUN. © 2011 Elsevier B.V."
"7004484970;7102291050;7402717381;8319623900;7003376335;6601945161;6602835531;","Weather systems occurring over Fort Simpson, Northwest Territories, Canada, during three seasons of 1998-1999: 1. Cloud features",2004,"10.1029/2004JD004876","https://www.scopus.com/inward/record.uri?eid=2-s2.0-14344260544&doi=10.1029%2f2004JD004876&partnerID=40&md5=c6df5d8fa78d80a700b68816a4575fbf","An investigation of high-latitude continental cloud systems was carried out in the interior of the Northwest Territories of Canada during three multiweek periods during the fall, winter, and spring of 1998-1999 as part of the Canadian Global Energy and Water Cycle Experiment (GEWEX) Enhanced Study. Radar data supplemented by satellite, upper air, and surface observations were used to determine the seasonal behavior of cloud macroscopic properties and compare these with similar observations elsewhere. Unique features included the prevalence of multilayered systems, the cold temperatures of low clouds, and a significant diurnal trend in cloud properties in the winter. A synoptic classification was developed and shown to be an important factor in explaining the variability of cloud properties. A consistent picture emerges of the upslope component and wind shear aloft contributing to the cloud structure in five synoptic classes. Vertically resolved cloud properties highlighted the importance of the ice process in these cloud systems. The cloud system reflectivity and temperature dependencies further supported the synoptic characterizations and highlighted the significance of using seasonally based relationships in automated cloud identification algorithms. The implication of the cloud system variability for radiation measurements was also shown. The radar reflectivity data, degraded to match CloudSat resolution and sensitivity, showed that cloud detection was reliable but that there was a positive bias with cloud thickness. Negative biases in cloud top retrievals based on advanced very high resolution radiometer data were also identified. The Global Environmental Multiscale model illustrated some degree of bias in the occurrence and vertical distribution of these cloud systems. Winter situations in general and midclouds situations in particular were the most poorly handled in both the satellite applications and the model simulations. Copyright 2004 by the American Geophysical Union."
"56228186500;","On the origin of small-scale structure in self-gravitating two-phase gas",1996,"10.1086/177461","https://www.scopus.com/inward/record.uri?eid=2-s2.0-21344462408&doi=10.1086%2f177461&partnerID=40&md5=ac7a211e0950466c2bda091d991e086b","We discuss the origin of multiscale structures in a mixture of a diffuse phase (phase I [PI]) and a dense phase (phase II [PII]) by linear analysis, using the notion of multiphase fluid dynamics (MPFD). We can then describe in terms of hydrodynamics how the seeds for small-scale structures, whose scale is smaller than the Jeans length, appear during the contraction of clouds. This suggests that our method can describe the origin of structure in self-gravitating gas systems. It is known that the systems with two-phase mixture of gases generally have two modes of waves according to MPFD. One mode (f-mode) corresponds to a sound wave, and the other mode (s-mode) is known as a void wave. The s-mode has smaller phase velocities in the two-phase medium than the f-mode. And since the s-mode is unstable against the self-gravity, seeds for smaller scale structure than the ordinary Jeans length can appear. This is because the repulsive effects by ambient phase I gas becomes less effective to the gravitational attractions among blobs of phase II gas. So the s-mode coupled with self-gravity may give rise to the clumpy structure in a molecular cloud, a globular cluster, and the interstellar medium of a galaxy. © 1996. The American Astronomical Society. All rights reserved."
"56010203200;6603874255;6507405241;56344286900;56596461000;55224026800;","Sensing the submerged landscape of Nisida Roman harbour in the gulf of Naples from integrated measurements on a USV",2018,"10.3390/w10111686","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85056797180&doi=10.3390%2fw10111686&partnerID=40&md5=3563d79a9000695bb8aba702e66fe081","This paper shows an interesting case of coastal landscape reconstruction by using innovative marine robotic instrumentation, applied to an archaeological key-site in the Campi Flegrei (Italy), one of the more inhabited areas in the Mediterranean during the Roman period. This active volcanic area is world famous for the ancient coastal cities of Baiae, Puteoli, and Misenum, places of military and commercial excellence. The multidisciplinary study of the submerged Roman harbour at Nisida Island was aimed at reconstructing the natural and anthropogenic underwater landscape by elaborating a multiscale dataset. The integrated marine surveys were carried out by an Unmanned Surface Vehicle (USV) foreseeing the simultaneous use of geophysical and photogrammetric sensors according to the modern philosophy of multi-modal mapping. All instrumental measurements were validated by on-site measurements performed by specialised scuba divers. The multiscale analysis of the sensing data allowed a precise reconstruction of the coastal morpho-evolutive trend and the relative sea level variation in the last 2000 years by means of a new type of archaeological sea-level marker here proposed for the first time. Furthermore, it provided a detailed multidimensional documentation of the underwater cultural heritage and a useful tool for evaluating the conservation state of archaeological submerged structures. © 2018 by the authors."
"56309988000;6506674287;14013141600;57193279737;55455157700;","Tracking fine-scale structural changes in coastal dune morphology using kite aerial photography and uncertainty-assessed structure-from-motion photogrammetry",2018,"10.3390/rs10091494","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053613723&doi=10.3390%2frs10091494&partnerID=40&md5=ea57ff9c9cd1a4c0663075cf5c3fb197","Coastal dunes are globally-distributed dynamic ecosystems that occur at the land-sea interface. They are sensitive to disturbance both from natural forces and anthropogenic stressors, and therefore require regular monitoring to track changes in their form and function ultimately informing management decisions. Existing techniques employing satellite or airborne data lack the temporal or spatial resolution to resolve fine-scale changes in these environments, both temporally and spatially whilst fine-scale in-situ monitoring (e.g., terrestrial laser scanning) can be costly and is therefore confined to relatively small areas. The rise of proximal sensing-based Structure-from-Motion Multi-View Stereo (SfM-MVS) photogrammetric techniques for land surface surveying offers an alternative, scale-appropriate method for spatially distributed surveying of dune systems. Here we present the results of an inter- and intra-annual experiment which utilised a low-cost and highly portable kite aerial photography (KAP) and SfM-MVS workflow to track sub-decimetre spatial scale changes in dune morphology over timescales of between 3 and 12 months. We also compare KAP and drone surveys undertaken at near-coincident times of the same dune system to test the KAP reproducibility. Using a Monte Carlo based change detection approach (Multiscale Model to Model Cloud Comparison (M3C2)) which quantifies and accounts for survey uncertainty, we show that the KAP-based survey technique, whilst exhibiting higher x, y, z uncertainties than the equivalent drone methodology, is capable of delivering data describing dune system topographical change. Significant change (according to M3C2); both positive (accretion) and negative (erosion) was detected across 3, 6 and 12 months timescales with the majority of change detected below 500 mm. Significant topographic changes as small as ~20 mm were detected between surveys. We demonstrate that portable, low-cost consumer-grade KAP survey techniques, which have been employed for decades for hobbyist aerial photography, can now deliver science-grade data, and we argue that kites are well-suited to coastal survey where winds and sediment might otherwise impede surveys by other proximal sensing platforms, such as drones. © 2018 by the authors."
"6701357289;26023394400;24331910600;6701799759;6602920994;","Aerosol pollution, including eroded soils, intensifies cloud growth, precipitation, and soil erosion: A review",2018,"10.1016/j.jclepro.2018.04.004","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85045712173&doi=10.1016%2fj.jclepro.2018.04.004&partnerID=40&md5=535505f0b88325946af46f5d77bc6788","The Earth's critical zone is vulnerable to atmospheric aerosol pollution due to aerosol impacts on cloud microphysics, precipitation characteristics, soil erosion, and the subsequent interactions of the soil-vegetation-atmosphere transfer of water, energy and aerosols. This review explains the individual and inter-connected processes of aerosol loading, cloud microphysics, precipitation characteristics, and soil erosion. A by-product of soil erosion is the generation of additional atmospheric aerosols, as well as the enhancement of surface erosion due to increased runoff. The literature includes empirical and theoretical studies within and across these domains. Case studies from China and Italy are provided to illustrate the key concepts connecting this system. The knowledge of the multiscale-impacts of aerosol pollution enables actions toward cleaner production processes to reduce aerosol pollution as well as forest and vegetation management to reduce soil erosion vulnerability. This review provides our community new insights on how to assess and manage earth's critical zone and our energy, food, water, and human resources. © 2018 Elsevier Ltd"
"6602740322;57192303572;","On the role of density and attenuation in three-dimensional multiparameter viscoacoustic VTI frequency-domain FWI: an OBC case study from the North Sea",2018,"10.1093/gji/ggy103","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85059988978&doi=10.1093%2fgji%2fggy103&partnerID=40&md5=51e8fd3b6c0d181f31443c908a6729bb","3-D frequency-domain full waveform inversion (FWI) is applied on North Sea wide-azimuth ocean-bottom cable data at low frequencies (≤10 Hz) to jointly update vertical wave speed, density and quality factor Qin the viscoacoustic VTI approximation. We assess whether density and Qshould be viewed as proxy to absorb artefacts resulting from approximate wave physics or are valuable for interpretation in the presence of soft sediments and gas cloud. FWI is performed in the frequency domain to account for attenuation easily. Multiparameter frequency-domain FWI is efficiently performed with a few discrete frequencies following a multiscale frequency continuation. However, grouping a few frequencies during each multiscale step is necessary to mitigate acquisition footprint and match dispersive shallow guided waves. Q and density absorb a significant part of the acquisition footprint hence cleaning the velocity model from this pollution. Low Q perturbations correlate with low-velocity zones associated with soft sediments and gas cloud. However, the amplitudes of the Q perturbations show significant variations when the inversion tuning is modified. This dispersion in the Q reconstructions is however not passed on the velocity parameter suggesting that cross-talks between first-order kinematic and second-order dynamic parameters are limited. The density model shows a good match with a well log at shallow depths. Moreover, the impedance built a posteriori from the FWI velocity and density models shows a well-focused image with however local differences with the velocity model near the sea bed where density might have absorbed elastic effects. The FWI models are finally assessed against time-domain synthetic seismogram modelling performed with the same frequency-domain modelling engine used for FWI. © The Author(s) 2018. Published by Oxford University Press on behalf of The Royal Astronomical Society."
"25648525300;55478977700;55574182494;35511789800;","Multiscale periodicities in aerosol optical depth over India",2013,"10.1088/1748-9326/8/1/014034","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876173325&doi=10.1088%2f1748-9326%2f8%2f1%2f014034&partnerID=40&md5=824875e5a675c477e9227836120b7875","Aerosols exhibit periodic or cyclic variations depending on natural and anthropogenic sources over a region, which can become modulated by synoptic meteorological parameters such as winds, rainfall and relative humidity, and long-range transport. Information on periodicity and phase in aerosol properties assumes significance in prediction as well as examining the radiative and climate effects of aerosols including their association with changes in cloud properties and rainfall. Periodicity in aerosol optical depth, which is a columnar measure of aerosol distribution, is determined using continuous wavelet transform over 35 locations (capitals of states and union territories) in India. Continuous wavelet transform is used in the study because continuous wavelet transform is better suited to the extraction of the periodic and local modulations present in various frequency ranges when compared to Fourier transform. Monthly mean aerosol optical depths (AODs) from the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Terra satellite at 1° × 1° resolution from January 2001 to December 2012 are used. Annual and quasi-biennial oscillations (QBOs) in AOD are evident in addition to the weak semi-annual (5-6 months) and quasi-triennial oscillations (∼40 months). The semi-annual and annual oscillations are consistent with the seasonal and yearly cycle of variations in AODs. The QBO type periodicity in AOD is found to be non-stationary while the annual period is stationary. The 40 month periodicity indicates the presence of long term correlations in AOD. The observed periodicities in MODIS Terra AODs are also evident in the ground-based AOD measurements made over Kanpur in the Indo-Gangetic Plain. The phase of the periodicity in AOD is stable in the mid-frequency range, while local disturbances in the high-frequency range and long term changes in the atmospheric composition give rise to unstable phases in the low-frequency range. The presence of phase relations among different locations reveals that modulations in AOD over a location/region can influence aerosol characteristics over other locations/regions. © 2013 IOP Publishing Ltd."
"35568218100;7006621313;7006184606;","Signature of microphysics on spatial rainfall statistics",2011,"10.1029/2010JD015124","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79960910834&doi=10.1029%2f2010JD015124&partnerID=40&md5=ccb940c3752d4872c4d68d86ed0141de","Previous studies have suggested that the statistical multiscale structure of rainfall can be parameterized in terms of thermodynamic descriptors of the storm environment, and such dependence has been successfully implemented in downscaling applications. In this paper we suggest that it is possible to adopt the raindrop terminal velocity as a physical parameter to explain to a large degree the statistical variability of convective rainfall over a range of scales. We examine this assertion by analysis of high-resolution simulations of an atmosphere in radiative-convective equilibrium performed using the Weather Research and Forecasting (WRF) model and prescribing different rain terminal velocity settings corresponding to small, slowly falling drops and large, quickly falling drops, respectively. The analysis has focused on the study of the dependence of some basic statistics of rainfall fields (probability distribution of convective rain cell areas, power spectra, and multiscale statistics of rainfall intensity) on the raindrop terminal velocity by using a well-documented and widely used atmospheric model. Possible applications of our results include downscaling of rainfall satellite measurements, conditional on limited microphysical information from dual-frequency spaceborne radars, and conversion of radar reflectivity to rain rate, conditional on drop size distribution inferred from the scaling parameters of the reflectivity fields. Copyright 2011 by the American Geophysical Union."
"22936388600;7005171879;","Wavelet analysis of cirrus multiscale structures from lidar backscattering: A cirrus uncinus complex case study",2008,"10.1175/2008JAMC1788.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-57749192454&doi=10.1175%2f2008JAMC1788.1&partnerID=40&md5=15d93ce18e53a8c30a38bb00e3a818f2","Although cirrus cloud structures play an important role in dynamics issues, cloud radiative calculations, and cloud parameter retrievals from satellite measurements, fully understanding cirrus cloud structures still remains a challenge. A case study of a cirrus containing mesoscale uncinus complexes (MUC) with a two-layer structure observed by a high-resolution lidar is presented using the method based on wavelet transform. The results indicate that dynamical processes play a leading role in determining cloud multiscale structures. The uncinus cells with a length scale on the order of ∼1 km, embedded in both the top and lower layers, have similar spectral features and are probably produced by a similar mechanism-thermal perturbation generated by heating and cooling effects associated with phase changes of water (i.e., adiabatic heating) and radiative processes. However, the mesoscale cloud patches are probably involved in different dynamics processes, suggesting that understanding of the interaction of cloud-scale convective activities with 2D turbulence and propagating gravity waves in cirrus cloud systems should receive more attention in future model simulations. The study also demonstrates the utility of the continuous and discrete wavelet transform to objectively and quantitatively analyze the properties of cirrus cloud structures, which is a useful supplement to the traditional Fourier transform method. © 2008 American Meteorological Society."
"7005685786;7006095466;7404476150;","A systematic analysis of multiscale deep convective variability over the tropical pacific",2004,"10.1175/1520-0442(2004)017<2736:ASAOMD>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-3242787497&doi=10.1175%2f1520-0442%282004%29017%3c2736%3aASAOMD%3e2.0.CO%3b2&partnerID=40&md5=c337a35bb93daac70291addd70c11df6","The multiscale tropical deep convective variability over the Pacific Ocean is examined with the 4-month highresolution deep convection index (ITBB) derived from satellite imagery. With a systemic view, the complex phenomenon is described with succinct parameters known as generalized dimensions associated with the correlation structures embedded in the observed time series, with higher-order dimensions emphasizing extreme convective events. It is suggested that convective activities of lifetimes ranging from 1 h to ∼21 days have interdependence across scales that can be described by a series of power laws; hence, a spectrum of generalized dimensions, that is, the ITBB time series is multifractal. The spatiotemporal features of the ITBB time series is preliminarily examined by changing the spatial domain from 0.1° × 0.1° to 25° × 25°. The multifractal features are weakened with increasing strength of spatial averaging but cannot be eliminated. Furthermore, the ITBB data has the property of long-range dependency, implying that its autocorrelation function decays with a power law in contrast to the zero or exponentially decaying autocorrelation functions for white and commonly used red noise processes generated from autoregressive models. Physically, this means that intensified convection tends to be followed by another intensified event, and vice versa for weakened events or droughts. Such tendency is stronger with larger domain averaging, probably due to more complete inclusion of larger-scale variability that has more definite trends, such as the supercloud clusters associated with the Madden-Julian oscillation (MJO). The evolution of cloud clusters within an MJO event is studied by following the MJO system across the analysis domain for ∼21 days. Convective activities along the front, center, and rear parts of the MJO event continuously intensify while approaching the date line, indicating multifractal features in the range of 1 h to about 5-10 days. Convective activity along the front and rear edges of the MJO event are more intermittent than in the center. The multifractal features of the ITBB time series can be approximated by the random multiplicative cascade processes, suggesting likely mechanisms for the multiscale behavior and casting concern on the predictability time scale of the observed phenomena. © 2004 American Meteorological Society."
"57203719531;7202844175;","The use of terrestrial laser scanning for the characterization of a cliff-talus system in the Thompson River Valley, British Columbia, Canada",2019,"10.1016/j.geomorph.2018.11.022","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85058077408&doi=10.1016%2fj.geomorph.2018.11.022&partnerID=40&md5=3b2bfadb9fa631eab9bba6900e122bd9","A postglacial river terrace along the Thompson River in Interior British Columbia, Canada has been monitored using terrestrial laser scanning (TLS) and high-resolution photography for almost a 3-year study to observe the deformation and failure processes, which result in changes in the slope morphology. Change detection using Multiscale Model to Model Cloud Comparison (M3C2) and a multi-scale dimensionality analysis (CANUPO) were performed on the 3-dimensional point cloud data to track the deposition patterns occurring in this active cliff talus system. Changes documented in the analysis of TLS data were verified using the high-resolution photography. Over 1.5 m of valley parallel retreat was captured in a section of the cliff face related to instability of a cobble and boulder horizon beneath a thick fluvial gravel unit. Because of the high-resolution remote sensing data, it was possible to observe a longitudinal sorting of grain sizes (i.e. fall sorting) in this cliff-talus system, whereby the size of individual particles controls the position on the slope. The overall mapped distribution of particle sizes on the slope remained constant for the almost 3-year study period. Flows of granular debris were observed in TLS change detection and the CANUPO analysis was able to display the longitudinal and lateral sorting of grain sizes that occurs during flow. This case history demonstrates that high resolution remote sensing data of large slopes permits us to link the geomorphic processes occurring in the cliff face with mass movement and deposition occurring on the talus slope below. © 2018 Elsevier B.V."
"57208087509;57207942766;57188649188;57201692252;35114218200;","Object-based convolutional neural networks for cloud and snow detection in high-resolution multispectral imagers",2018,"10.3390/w10111666","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85056596297&doi=10.3390%2fw10111666&partnerID=40&md5=67a73263442342c0bacf69853cd503d7","Cloud and snow detection is one of the most significant tasks for remote sensing image processing. However, it is a challenging task to distinguish between clouds and snow in high-resolution multispectral images due to their similar spectral distributions. The shortwave infrared band (SWIR, e.g., Sentinel-2A 1.55-1.75 μm band) is widely applied to the detection of snow and clouds. However, high-resolution multispectral images have a lack of SWIR, and such traditional methods are no longer practical. To solve this problem, a novel convolutional neural network (CNN) to classify cloud and snow on an object level is proposed in this paper. Specifically, a novel CNN structure capable of learning cloud and snow multiscale semantic features from high-resolution multispectral imagery is presented. In order to solve the shortcoming of ""salt-and-pepper"" in pixel level predictions, we extend a simple linear iterative clustering algorithm for segmenting high-resolution multispectral images and generating superpixels. Results demonstrated that the new proposed method can with better precision separate the cloud and snow in the high-resolution image, and results are more accurate and robust compared to the other methods. © 2018 by the authors."
"36705265400;36339753800;56533742600;","Size-resolved evaluation of simulated deep tropical convection",2018,"10.1175/MWR-D-17-0378.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050107463&doi=10.1175%2fMWR-D-17-0378.1&partnerID=40&md5=87393d9d20cd39e1e6e3e4d4760ce9ee","Deep moist convection is an inherently multiscale phenomenon with organization processes coupling convective elements to larger-scale structures. A realistic representation of the tropical dynamics demands a simulation framework that is capable of representing physical processes across a wide range of scales. Therefore, storm-resolving numerical simulations at 2.4 km have been performed covering the tropical Atlantic and neighboring parts for 2 months. The simulated cloud fields are combined with infrared geostationary satellite observations, and their realism is assessed with the help of object-based evaluation methods. It is shown that the simulations are able to develop a well-defined intertropical convergence zone. However, marine convective activity measured by the cold cloud coverage is considerably underestimated, especially for the winter season and the western Atlantic. The spatial coupling across the resolved scales leads to simulated cloud number size distributions that follow power laws similar to the observations, with slopes steeper in winter than summer and slopes steeper over ocean than over land. The simulated slopes are, however, too steep, indicating too many small and too few large tropical cloud cells. It is also discussed that the number of larger cells is less influenced by multiday variability of environmental conditions. Despite the identified deficits, the analyzed simulations highlight the great potential of this modeling framework for process-based studies of tropical deep convection. © 2018 American Meteorological Society."
"57190880220;7006621313;7004114883;","Global multiscale evaluation of satellite passive microwave retrieval of precipitation during the TRMM and GPM eras: Effective resolution and regional diagnostics for future algorithm development",2017,"10.1175/JHM-D-17-0087.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85035798165&doi=10.1175%2fJHM-D-17-0087.1&partnerID=40&md5=ec01a6b289d4c58dc2c39cee0d03f036","The constellation of spaceborne passive microwave (MW) sensors, coordinated under the framework of the Precipitation Measurement Missions international agreement, continuously produces observations of clouds and precipitation all over the globe. The Goddard profiling algorithm (GPROF) is designed to infer the instantaneous surface precipitation rate from the measured MW radiances. The last version of the algorithm (GPROF-2014)-the product of more than 20 years of algorithmic development, validation, and improvement-is currently used to estimate precipitation rates from the microwave imager GMI on board the GPM core satellite. The previous version of the algorithm (GPROF-2010) was used with the microwave imager TMI on board TRMM. In this paper, TMI-GPROF-2010 estimates and GMI-GPROF-2014 estimates are compared with coincident active measurements from the Precipitation Radar on board TRMM and the Dual-Frequency Precipitation Radar on board GPM, considered as reference products. The objective is to assess the improvement of the GPM-era microwave estimates relative to the TRMM-era estimates and diagnose regions where continuous improvement is needed. The assessment is oriented toward estimating the ""effective resolution"" of the MW estimates, that is, the finest scale at which the retrieval is able to accurately reproduce the spatial variability of precipitation. A wavelet-based multiscale decomposition of the radar and passive microwave precipitation fields is used to formally define and assess the effective resolution. It is found that the GPM-era MW retrieval can resolve finer-scale spatial variability over oceans than the TRMM-era retrieval. Over land, significant challenges exist, and this analysis provides useful diagnostics and a benchmark against which future retrieval algorithm improvement can be assessed. © 2017 American Meteorological Society."
"57198945375;57203579757;57000410500;","Design and implementation of a GSI-based convection-allowing ensemble-based data assimilation and forecast system for the PECAN field experiment. Part II: Overview and evaluation of a real-time system",2017,"10.1175/WAF-D-16-0201.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85020029341&doi=10.1175%2fWAF-D-16-0201.1&partnerID=40&md5=053a30cb7939aadf73d292f2c5185f3d","Multiscale ensemble-based data assimilation and forecasts were performed in real time during the Plains Elevated Convection At Night (PECAN) field experiment. A 20-member ensemble of forecasts at 4-km grid spacing was initialized daily at both 1300 and 1900 UTC, together with a deterministic forecast at 1-km grid spacing initialized at 1300 UTC. The configuration of the GSI-based data assimilation and forecast system was guided by results presented in Part I of this two-part study. The present paper describes the implementation of the real-time system and the extensive forecast products that were generated to support the unique interests of PECAN researchers. Subjective and objective verification of the real-time forecasts from 1 June through 15 July 2015 is conducted, with an emphasis on nocturnal mesoscale convective systems (MCSs), nocturnal convective initiation (CI), nocturnal low-level jets (LLJs), and bores on the nocturnal stable layer. Verification of nocturnal precipitation during overnight hours, a proxy for MCSs, shows both greater skill and spread for the 1300 UTC forecasts than the 1900 UTC forecasts. Verification against observed soundings reveals that the forecast LLJs systematically peak, veer, and dissipate several hours before the observations. Comparisons with bores that passed over an Atmospheric Emitted Radiance Interferometer reveal an ability to predict borelike features that is greatly improved at 1-km, compared with 4-km, grid spacing. Objective verification of forecast CI timing reveals strong sensitivity to the PBL scheme but an overall unbiased ensemble. © 2017 American Meteorological Society."
"14631111100;6506703348;35578922100;56668704400;35584010200;56427880900;57192942594;57192940228;57192937668;57192940254;56921163600;57192939169;57192941029;36473630000;55241167300;","Characteristics of Precipitating Storms in Glacierized Tropical Andean Cordilleras of Peru and Bolivia",2017,"10.1080/24694452.2016.1260439","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85009259804&doi=10.1080%2f24694452.2016.1260439&partnerID=40&md5=77de4f8ccc8dbd9c69bd6de218fbd971","Precipitation variability in tropical high mountains is a fundamental yet poorly understood factor influencing local climatic expression and a variety of environmental processes, including glacier behavior and water resources. Precipitation type, diurnality, frequency, and amount influence hydrological runoff, surface albedo, and soil moisture, whereas cloud cover associated with precipitation events reduces solar irradiance at the surface. Considerable uncertainty remains in the multiscale atmospheric processes influencing precipitation patterns and their associated regional variability in the tropical Andes—particularly related to precipitation phase, timing, and vertical structure. Using data from a variety of sources—including new citizen science precipitation stations; new high-elevation comprehensive precipitation monitoring stations at Chacaltaya, Bolivia, and the Quelccaya Ice Cap, Peru; and a vertically pointing Micro Rain Radar—this article synthesizes findings from interdisciplinary research activities in the Cordillera Real of Bolivia and the Cordillera Vilcanota of Peru related to the following two research questions: (1) How do the temporal patterns, moisture source regions, and El Niño-Southern Oscillation relationships with precipitation occurrence vary? (2) What is the vertical structure (e.g., reflectivity, Doppler velocity, melting layer heights) of tropical Andean precipitation and how does it evolve temporally? Results indicate that much of the heavy precipitation occurs at night, is stratiform rather than convective in structure, and is associated with Amazonian moisture influx from the north and northwest. Improving scientific understanding of tropical Andean precipitation is of considerable importance to assessing climate variability and change, glacier behavior, hydrology, agriculture, ecosystems, and paleoclimatic reconstructions. © 2017 by American Association of Geographers."
"9249605700;","Relationship between cumulus activity and environmental moisture during the CINDY2011/DYNAMO field experiment as revealed from convection-resolving simulations",2016,"10.2151/jmsj.2015-035","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84955146470&doi=10.2151%2fjmsj.2015-035&partnerID=40&md5=d9b613f91be9ad7c774c1924024a2255","The cumulus convection activity in the tropical oceanic regions is strongly regulated by the large-scale environmental atmosphere, while at the same time, cumulus convection will influence the large-scale atmosphere. It is thus recognized that the spatiotemporal variability of moisture content plays an important role in determining such multiscale interaction processes relevant to tropical cumulus convection. This study investigates the relationship between cumulus convection and environmental moisture in the tropical Indian Ocean by conducting convection- resolving simulations through the nesting capability with which the innermost domain has the 100 m grid resolution. We examine the cases observed from October to November 2011 during the Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011/Dynamics of the Madden–Julian oscillation (MJO) field experiment. Based on the favorable performance of the outermost domain simulations in reproducing eastward propagating signals over the Indian Ocean, the data obtained from the 100 m mesh simulations are examined. It is shown that the cloud cover whose tops exceed a middle level sharply increases with the increase in precipitable water vapor over about 55 mm. The increase in relative humidity in a lower layer results in the increase in cloud cover at a level above the humid layer. From the convection-resolving simulations, the existence of updraft cores that are less diluted with the environment is demonstrated. It is considered that cloud-core parcels are less susceptible to the negative effects of dilution with the environment and survive to penetrate to upper levels, which contributes to the moistening of the environmental atmosphere. The existence of updraft cores plays a key role in the inter-relationship between cumulus convection and its environment. The effects from cumulus clouds on their environment are regarded as a preconditioning influence for the convective initiation of MJO. © 2015, Meteorological Society of Japan."
"7409074131;37116849700;56611366900;8859530100;55745955800;37018824600;6701333444;55272477500;","Development of fine-resolution analyses and expanded large-scale forcing properties: 1. Methodology and evaluation",2015,"10.1002/2014JD022245","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84923173815&doi=10.1002%2f2014JD022245&partnerID=40&md5=f2bb6e4cc2a97d3eef8ece548c7a935e","We produce fine-resolution, three-dimensional fields of meteorological and other variables for the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Southern Great Plains site. The Community Gridpoint Statistical Interpolation system is implemented in a multiscale data assimilation (MS-DA) framework that is used within the Weather Research and Forecasting model at a cloud-resolving resolution of 2 km. The MS-DA algorithm uses existing reanalysis products and constrains fine-scale atmospheric properties by assimilating high-resolution observations. A set of experiments show that the data assimilation analysis realistically reproduces the intensity, structure, and time evolution of clouds and precipitation associated with a mesoscale convective system. Evaluations also show that the large-scale forcing derived from the fine-resolution analysis has an overall accuracy comparable to the existing ARM operational product. For enhanced applications, the fine-resolution fields are used to characterize the contribution of subgrid variability to the large-scale forcing and to derive hydrometeor forcing, which are presented in companion papers. © 2014. American Geophysical Union. All Rights Reserved."
"36638084000;7004771001;36452143600;7406139869;57194133671;55505800100;36452110300;36451955900;56730208100;55398749600;7202603773;6506993959;12239409800;55721375400;","Stratospheric imaging of polar mesospheric clouds: A new window on small-scale atmospheric dynamics",2015,"10.1002/2015GL064758","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84938976608&doi=10.1002%2f2015GL064758&partnerID=40&md5=a3c91cb2a52b0aa5b529b45dc249389f","Instabilities and turbulence extending to the smallest dynamical scales play important roles in the deposition of energy and momentum by gravity waves throughout the atmosphere. However, these dynamics and their effects have been impossible to quantify to date due to lack of observational guidance. Serendipitous optical images of polar mesospheric clouds at ∼82 km obtained by star cameras aboard a cosmology experiment deployed on a stratospheric balloon provide a new observational tool, revealing instability and turbulence structures extending to spatial scales &lt; 20 m. At 82 km, this resolution provides sensitivity extending to the smallest turbulence scale not strongly influenced by viscosity: the ""inner scale"" of turbulence, l0∼10(ν3/ε)1/4. Such images represent a new window into small-scale dynamics that occur throughout the atmosphere but are impossible to observe in such detail at any other altitude. We present a sample of images revealing a range of dynamics features and employ numerical simulations that resolve these dynamics to guide our interpretation of several observed events. © 2015. American Geophysical Union. All Rights Reserved."
"55675283100;7404521962;16402575500;35105101800;26531406100;6701764745;6506385754;","Distributions of ice supersaturation and ice crystals from airborne observations in relation to upper tropospheric dynamical boundaries",2015,"10.1002/2015JD023139","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84932169010&doi=10.1002%2f2015JD023139&partnerID=40&md5=3ad0bf4e72a7673ce3a6cfd187367e87","Ice supersaturation (ISS) is the prerequisite condition for cirrus cloud formation. To examine multiscale dynamics’ influences on ISS formation, we analyze in situ aircraft observations (~200m scale) over North America in coordinates relative to dynamical boundaries in the upper troposphere and lower stratosphere. Two case studies demonstrate that ISS formation is likely influenced by mesoscale uplifting, small-scale waves, and turbulence. A collective analysis of 15 flights in April–June 2008 shows that the top layers of ISS and ice crystal distributions are strongly associated with thermal tropopause height. In addition, the average occurrence frequencies of ISS and ice crystals on the anticyclonic side of the jet stream are ~1.5–2 times of those on the cyclonic side. By defining five cirrus evolution phases based on the spatial relationships between ice-supersaturated and in-cloud regions, we find that their peak occurrence frequencies are located at decreasing altitudes with respect to the thermal tropopause: (phase 1) clear-sky ISS around the tropopause, (phase 2) nucleation phase around 2 km below the tropopause, (phases 3 and 4) early and later growth phases around 6 km below the tropopause, and (phase 5) sedimentation/sublimation around 2–6km below the tropopause. Consistent with this result, chemical tracer correlation analysis shows that the majority (~80%) of the earlier cirrus phases (clear-sky ISS and nucleation) occurs inside the chemical tropopause transition layer, while the later phases happen mostly below that layer. These results shed light on the role of dynamical environment in facilitating cirrus cloud formation and evolution. © 2015. American Geophysical Union. All rights reserved."
"14040398300;36538539800;6603262263;6701497749;","Examining the sensitivity of MM5-CMAQ predictions to explicit microphysics schemes and horizontal grid resolutions, Part I-Database, evaluation protocol, and precipitation predictions",2008,"10.1016/j.atmosenv.2007.12.067","https://www.scopus.com/inward/record.uri?eid=2-s2.0-43149100111&doi=10.1016%2fj.atmosenv.2007.12.067&partnerID=40&md5=851429a0e816f56f1c9e4e9a923f2f7a","Wet deposition of chemical species is one of the most difficult processes to simulate in three-dimensional (3-D) air quality models, due to the complex interplay among meteorology, cloud, and atmospheric chemistry. Different cloud microphysical treatments and horizontal grid resolutions in 3-D models can directly affect simulated clouds, precipitation, and wet deposition. In this study, the performance and sensitivity of the simulated precipitation, concentrations, and wet deposition to different explicit microphysics schemes and horizontal grid resolutions are evaluated for August and December 2002 for a domain centered over North Carolina (NC). Four explicit microphysics schemes in MM5 are examined: Reisner 1 (R1), Reisner 2 (R2), Dudhia (SI), and Hsie (WR). The precipitation evaluation indicates that monthly-average precipitation amounts are underpredicted by all schemes in both August and December at all sites except for the R1 August simulation that shows overpredictions at National Acid Deposition Program (NADP) sites. An increased sensitivity to microphysics schemes is found at locations in both the coastal plain and mountain regions in August and the mountain region in December. The differences in simulation results in August and December are mainly attributed to seasonal differences in dominant meteorological forcing (mesoscale vs. synoptic, respectively). Among the schemes tested, R2 and SI give the best overall performance in predicting precipitation for both months. These findings are applicable for NC and neighboring states with similar meteorological and emission characteristics."
"23396339900;6603593523;6701839777;55999400600;","A multifractal approach for extracting relevant textural areas in satellite meteorological images",2007,"10.1016/j.envsoft.2005.07.032","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33749681657&doi=10.1016%2fj.envsoft.2005.07.032&partnerID=40&md5=33b386c54810f713d0e746e2dfe40043","In the latest years, the use of computer vision tools for automatically analyzing the large amount of data acquired by remote sensing has grown in importance and number of different applications, ranging from basic research to industry. However, images displaying natural phenomena, and especially turbulence, develop following complicated patterns which are difficult to segment and to analyze with those tools. In this paper, we discuss on the use of new image processing methods to describe complicated flow and flow-like quantities, in applications such as meteorology. Using infrared satellite images as an example, we show that we are naturally led to gain insight in the physical and geometrical properties of the observed complex structures. We analyze different processing techniques (multiscale texture classification and multifractal decomposition and reconstruction) issued from the so-called multiscale methodology. The efficiency of multiscale methodology lies on its ability of reproducing known, experimental physical properties of the systems in study (such as scale invariance or multiscaling exponents) in the analysis scheme of images. We show that this methodology can be further exploited in order to derive information about a dynamical property from still infrared images. Namely, the main goal of our study is to detect and characterize textural areas at which typical convective movements take place. For that purpose, we compare the actual graylevel distribution in images, providing information about the temperature distribution, and a synthetic graylevel distribution induced by the multifractal formalism, also reinterpreted by its connection with thermodynamics. The conclusions of our work can be generalized to any analogous physical system. © 2005 Elsevier Ltd. All rights reserved."
"8623918800;7102101132;","Rapid scan views of convectively generated mesovortices in sheared tropical cyclone Gustav (2002)",2006,"10.1175/WAF950.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33846264080&doi=10.1175%2fWAF950.1&partnerID=40&md5=4453a51b714c6feb31512e1036542968","On 9-10 September 2002, multiple mesovortices were captured in great detail by rapid scan visible satellite imagery in subtropical, then later, Tropical Storm Gustav. These mesovortices were observed as low-level cloud swirls while the low-level structure of the storm was exposed due to vertical shearing. They are shown to form most plausibly via vortex tube stretching associated with deep convection; they become decoupled from the convective towers by vertical shear; they are advected with the low-level circulation; finally they initiate new hot towers on their boundaries. Partial evidence of an axisymmetrizing mesovortex and its hypothesized role in the parent vortex spinup is presented. Observations from the mesoscale and synoptic scale are synthesized to provide a multiscale perspective of the intensification of Gustav that occurred on 10 September. The most important large-scale factors were the concurrent relaxation of the 850-200-hPa-deep layer vertical wind shear from 10-15 to 5-10 m s-1 and movement over pockets of very warm sea surface temperatures (approximately 29.5°-30.5°C). The mesoscale observations are not sufficient alone to determine the precise role of the deep convection and mesovortices in the intensification. However, qualitative comparisons are made between the mesoscale processes observed in Gustav and recent full-physics and idealized numerical simulations to obtain additional insight. © 2006 American Meteorological Society."
"7004909806;","Linearization of a simple moist convection scheme for large-scale NWP models",2005,"10.1175/MWR2942.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-24944443047&doi=10.1175%2fMWR2942.1&partnerID=40&md5=479bbccd4ae5ecb85204aa6b214b3f1d","A simple Kuo-type convection scheme with an improved closure based on moist enthalpy accession (Kuo symmetric) has been linearized for the tangent-linear (TL) and adjoint (AD) versions of the Global Environmental Multiscale (GEM) model. The nonlinear scheme exhibits a reasonable behavior in terms of heating and moistening rates when evaluated in stand-alone mode over a set of deep convective profiles. A preliminary evaluation of a straightforward linearization in the global TL model has revealed the existence of noise that leads to an unacceptable solution after 12 h of integration. By neglecting several terms in the linearization (detrainment rate and cloud properties), the temporal evolution of humidity analysis increments is improved by including this simplified linearized convection scheme in the TL model. The behavior of the linearized scheme has also been compared favorably to the linearized version of the European Centre for Medium-Range Weather Forecasts (ECMWF) mass-flux convection scheme. When examining the validity of the TL approximation for surface precipitation, it appears that linearization errors are large for both stratiform and convective rainfall (rms errors are about twice the mean absolute perturbed precipitation). These errors are not reduced when considering accumulated rain rates instead of instantaneous quantities. However, the occurrence of ""on-off"" processes is reduced by a temporal integration of rain. This could make the variational assimilation of accumulated precipitation rates easier. Finally, errors coming from internal nonlinearities are slightly larger than those produced by discontinuities. This confirms the interest for improving the linearity of nonlinear convection schemes for applications in variational contexts. © 2005 American Meteorological Society."
"56416175400;57204950288;55910431900;56556776300;7101867299;7006244721;","Quantitative view on the processes governing the upscale error growth up to the planetary scale using a stochastic convection scheme",2019,"10.1175/MWR-D-18-0292.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85064811818&doi=10.1175%2fMWR-D-18-0292.1&partnerID=40&md5=c1644964fc460bf3b7a8d8cb18dba538","Two diagnostics based on potential vorticity and the envelope of Rossby waves are used to investigate upscale error growth from a dynamical perspective. The diagnostics are applied to several cases of global, real-case ensemble simulations, in which the only difference between the ensemble members lies in the random seed of the stochastic convection scheme. Based on a tendency equation for the enstrophy error, the relative importance of individual processes to enstrophy-error growth near the tropopause is quantified. After the enstrophy error is saturated on the synoptic scale, the envelope diagnostic is used to investigate error growth up to the planetary scale. The diagnostics reveal distinct stages of the error growth: in the first 12 h, error growth is dominated by differences in the convection scheme. Differences in the upper-tropospheric divergent wind then project these diabatic errors into the tropopause region (day 0.5-2). The subsequent error growth (day 2-14.5) is governed by differences in the nonlinear near-tropopause dynamics. A fourth stage of the error growth is found up to 18 days when the envelope diagnostic indicates error growth from the synoptic up to the planetary scale. Previous ideas of the multiscale nature of upscale error growth are confirmed in general. However, a novel interpretation of the governing processes is provided. The insight obtained into the dynamics of upscale error growth may help to design representations of uncertainty in operational forecast models and to identify atmospheric conditions that are intrinsically prone to large error amplification. © 2019 American Meteorological Society."
"57191835635;7006684098;36562536000;57161462100;55946457200;57204514339;","Exploring cloud-based Web Processing Service: A case study on the implementation of CMAQ as a Service",2019,"10.1016/j.envsoft.2018.11.019","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85058803779&doi=10.1016%2fj.envsoft.2018.11.019&partnerID=40&md5=13021df7e0be4cd9bf7e584b1108eed4","As an important tool for air quality simulation, the Community Multiscale Air Quality (CMAQ) model is widely used in the environmental modeling community. However, setting up and running the CMAQ model could be challenging for many scientists, especially when they have limited computing resources and little experience in handling large-scale input data. In this study, we explore the cloud-based Web Processing Service (WPS) and present the Cloud WPS framework to support implementing Earth science model as WPS. Specifically, to make CMAQ easier to use for scientists through the latest standard-based Web service technology, CMAQ-WS, a prototype of CMAQ as a Service, is developed and tested. The result of the experiment shows the framework significantly improves not only the performance of but also ease of use of the CMAQ model thus providing great benefits to the environmental modeling community. Meanwhile, the proposed framework provides a general solution to integrate Earth science model, WPS, and cloud infrastructure, which can greatly reduce the workload of Earth scientists. © 2018 Elsevier Ltd"
"57200293072;22134685800;","Mapping wild leek through the forest canopy using a UAV",2018,"10.3390/rs10010070","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85040693987&doi=10.3390%2frs10010070&partnerID=40&md5=f341eeaf67bb4dc6084158e56fc91f92","Wild leek, an endangered plant species of Eastern North America, grows on forest floors and greens up to approximately three weeks before the trees it is typically found under, temporarily allowing it to be observed through the canopy by remote sensing instruments. This paper explores the accuracy with which wild leek can be mapped with a low-flying UAV. Nadir video imagery was obtained using a commercial UAV during the spring of 2017 in Gatineau Park, Quebec. Point clouds were generated from the video frames with the Structure-from-Motion framework, and a multiscale curvature classification was used to separate points on the ground, where wild leek grows, from above-ground points belonging to the forest canopy. Five-cm resolution orthomosaics were created from the ground points, and a threshold value of 0.350 for the green chromatic coordinate (GCC) was applied to delineate wild leek from wood, leaves, and other plants on the forest floor, with an F1-score of 0.69 and 0.76 for two different areas. The GCC index was most effective in delineating bigger patches, and therefore often misclassified patches smaller than 30 cm in diameter. Although short flight times and long data processing times are presently technical challenges to upscaling, the low cost and high accuracy of UAV imagery provides a promising method for monitoring the spatial distribution of this endangered species."
"15135583300;6603381720;","Electrification and lightning in idealized simulations of a hurricane-like vortex subject to wind shear and sea surface temperature cooling",2017,"10.1175/JAS-D-16-0270.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85020307843&doi=10.1175%2fJAS-D-16-0270.1&partnerID=40&md5=32b59206195b3f7d0cc9d3f111697ce7","Relationships between intensity fluctuations, cloud microphysics, lightning variations, and electrical structures within idealized tropical cyclones are investigated with the cloud-resolving Collaborative Model for Multiscale Atmospheric Simulation (COMMAS). An initial strong tropical cyclone is subjected to either steady-state control conditions (CTRL), increased wind shear (SHEAR), or a reduction in sea surface temperature (SST). In CTRL, nearly all the lightning ( > 95%) occurred in the outer region (100 < r ≤ 300 km) and was overall very episodic in the inner core (r ≤ 100 km), consistent with observations. The inner-core updrafts were weaker and experienced greater depletion of cloud water by warm rain processes, which, in contrast to the deeper updrafts in the rainband convection, reduced the mixed-phase cloud depth and confined the bulk of the charging and lightning initiations to lower levels. Notably, larger flash rates were produced in the asymmetric inner core of the SHEAR case, with the majority of the flashes located in the downshear left quadrant, consistent with prior observational works. In contrast to CTRL, the more vigorous inner-core convection in SHEAR resulted in the formation of a prominent negative charge region and enhanced production of negative ground flashes. With a nearly identical filling rate as SHEAR, the introduction of cooler sea surface temperature in the SST case caused lightning activity to fade rapidly in both the inner core and rainbands. © 2017 American Meteorological Society."
"55438009600;56448067500;55645567200;7201381456;57154891500;","Influence of regional climate change on meteorological characteristics and their subsequent effect on ozone dispersion in Taiwan",2015,"10.1016/j.atmosenv.2014.12.020","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84918508254&doi=10.1016%2fj.atmosenv.2014.12.020&partnerID=40&md5=4d600d8943e8945cb6b7a1221506f4e2","The objective of this study is to understand the influence of regional climate change on local meteorological conditions and their subsequent effect on local ozone (O3) dispersion in Taiwan. The 33-year NCEP-DOE Reanalysis 2 (NNR2) data set (1979-2011) was analyzed to understand the variations in regional-scale atmospheric conditions in East Asia and the western North Pacific. To save computational processing time, two scenarios representative of past (1979-86) and current (2004-11) atmospheric conditions were selected but only targeting the autumn season (September, October and November) when the O3 concentrations were at high levels. Numerical simulations were performed using weather research and forecasting (WRF) model and Community Multiscale Air Quality (CMAQ) model for the past and current scenarios individually but only for the month of October because of limited computational resources.Analysis of NNR2 data exhibited increased air temperature, weakened Asian continental anticyclone, enhanced northeasterly monsoonal flow, and a deepened low-pressure system forming near Taiwan. With enhanced evaporation from oceans along with a deepened low-pressure system, precipitation amounts increased in Taiwan in the current scenario. As demonstrated in the WRF simulation, the land surface physical process responded to the enhanced precipitation resulting in damper soil conditions, and reduced ground temperatures that in turn restricted the development of boundary layer height. The weakened land-sea breeze flow was simulated in the current scenario. With reduced dispersion capability, air pollutants would tend to accumulate near the emission source leading to a degradation of air quality in this region. The conditions would be even worse in southwestern Taiwan due to the fact that stagnant wind fields would occur more frequently in the current scenario. On the other hand, in northern Taiwan, the simulated O3 concentrations are lower during the day in the current scenario due to the enhanced cloud conditions and reduced solar radiation. © 2014 Elsevier Ltd."
"8644853100;57191361572;35233917200;","Thin cloud removal from remote sensing images using multidirectional dual tree complex wavelet transform and transfer least square support vector regression",2015,"10.1117/1.JRS.9.095053","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84942694206&doi=10.1117%2f1.JRS.9.095053&partnerID=40&md5=42c267ec993727b775e3ed35ae4a43c5","The existence of clouds affects the interpretation and utilization of remote sensing images. A thin cloud removal algorithm for cloud-contaminated remote sensing images is proposed by combining a multidirectional dual tree complex wavelet transform (M-DTCWT) with domain adaptation transfer least square support vector regression (T-LSSVR). First, M-DTCWT is constructed by using the hourglass filter bank in combination with DTCWT, which is used to decompose remote sensing images into multiscale and multidirectional subbands. Then the low-frequency subband coefficients of the cloud-free regions on target images and source domain images are used as samples for a T-LSSVR model, which can be used to predict those of the cloud regions on cloud-contaminated images. Finally, by enhancing the high-frequency coefficients and replacing the low-frequency coefficients, the thin clouds on cloud-contaminated images are removed. Experimental results show that M-DTCWT contributes to keeping the details of the ground objects of cloud-contaminated images, and the T-LSSVR model can effectively learn the contour information from multisource and multitemporal images, therefore, the proposed method achieves a good effect of thin cloud removal. © 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)."
"34168355400;56709175600;24466540100;55390085400;","Performance comparison of CMAQ and CAMx for one-year PM2.5 simulation in Japan",2015,"10.1504/IJEP.2015.074498","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84941969507&doi=10.1504%2fIJEP.2015.074498&partnerID=40&md5=1b66e0eb405c92fdc9fb1a3dcd0534a9","This study evaluated one-year performance of the community multiscale air quality (CMAQ) model v5.0.1 and the comprehensive air quality model with extensions (CAMx) v6.00. One-year air quality simulations were conducted with common input meteorology, emission and boundary concentration data in the Kinki region of Japan. CAMx-simulated ground-level concentrations were generally higher by 10%-20% than CMAQ-simulated values. Despite the systematical difference, the overall one-year performances of the two models for simulating ground-level concentrations were similar to each other according to comparisons with observed data. The two models approximately reproduced mass concentrations of fine particulate matter (PM2.5), but shared common difficulties in simulating PM2.5 components. The models substantially underestimated organic aerosol, which was compensated by overestimate of dust transported from the Asian continent. In addition, the systematical difference between the CMAQ-And CAMx-simulated ground-level PM2.5 concentrations was mainly attributed to the treatment of the vertical diffusivity and the below-cloud scavenging. Copyright © 2015 Inderscience Enterprises Ltd."
"8688004400;6603263640;7004978125;57193882808;","Multiscale interactions in an idealized walker cell: Simulations with sparse space-time superparameterization",2015,"10.1175/MWR-D-14-00082.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84928880608&doi=10.1175%2fMWR-D-14-00082.1&partnerID=40&md5=d3ae642fd7bffe879c09052d38c4c621","This paper discusses the sparse space-time superparameterization (SSTSP) algorithm and evaluates its ability to represent interactions between moist convection and the large-scale circulation in the context of aWalker cell flow over a planetary scale two-dimensional domain. The SSTSP represents convective motions in each column of the large-scale model by embedding a cloud-resolving model, and relies on a sparse sampling in both space and time to reduce computational cost of explicit simulation of convective processes. Simulations are performed varying the spatial compression and/or temporal acceleration, and results are compared to the cloud-resolving simulation reported previously. The algorithm is able to reproduce a broad range of circulation features for all temporal accelerations and spatial compressions, but significant biases are identified. Precipitation tends to be too intense and too localized over warm waters when compared to the cloud-resolving simulations. It is argued that this is because coherent propagation of organized convective systems from one large-scale model column to another is difficult when superparameterization is used, as noted in previous studies. The Walker cell in all simulations exhibits low-frequency variability on a time scale of about 20 days, characterized by four distinctive stages: suppressed, intensification, active, and weakening. The SSTSP algorithm captures spatial structure and temporal evolution of the variability. This reinforces the confidence that SSTSP preserves fundamental interactions between convection and the large-scale flow, and offers a computationally efficient alternative to traditional convective parameterizations. © 2015 American Meteorological Society."
"8977001000;7403282069;","An explicit representation of vertical momentum transport in a multiscale modeling framework through its 2-d cloud-resolving model component",2014,"10.1002/2013JD021078","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84898465921&doi=10.1002%2f2013JD021078&partnerID=40&md5=cd88028dd366b12a697aa43df0d4a8cd","In this study, an explicit representation of vertical momentum transport by convective cloud systems, including mesoscale convective systems (MCSs), is proposed and tested in a multiscale modeling framework (MMF). The embedded cloud-resolving model (CRM) provides vertical momentum transport in one horizontal direction. The vertical momentum transport in the other direction is assumed to be proportional to the vertical mass flux diagnosed from the CRM in addition to the effects of entrainment and detrainment. In order to represent both upgradient and downgradient vertical momentum transports, the orientation of the embedded CRM must change with time instead of being stationary typically in MMFs. The orientation is determined by the stratification of the lower troposphere and environmental wind shear. Introducing the variation of the orientations of the embedded CRM is responsible for reducing the stationary anomalous precipitation and many improvements. Improvements are strengthened when the CRM simulated vertical momentum transport is allowed to modify the large-scale circulation simulated by the host general circulation model. These include an improved spatial distribution, amplitude, and intraseasonal variability of the surface precipitation in the tropics, more realistic zonal mean diabatic heating and drying patterns, more reasonable zonal mean large-scale circulations and the East Asian summer monsoon circulation, and an improved, annual mean implied meridional ocean transport in the Southern Hemisphere. Further tests of this convective momentum transport parameterization scheme will be performed with a higher-resolution MMF to further understand its roles in the intraseasonal oscillation and tropical waves, monsoon circulation, and zonal mean large-scale circulations. © 2014. American Geophysical Union. All rights reserved."
"36987319800;57203054708;","Modeling the moist-convective atmosphere with a Quasi-3-D Multiscale Modeling Framework (Q3D MMF)",2014,"10.1002/2013MS000295","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84899097139&doi=10.1002%2f2013MS000295&partnerID=40&md5=32af3488746bda2b187dc71defa525a0","The Q3D MMF (Quasi-Three-Dimensional Multiscale Modeling Framework) is a new generation of MMF that replaces the conventional subgrid-scale parameterizations in general circulation models (GCMs) with explicit simulations of cloud and associated processes by cloud-resolving models (CRMs). In the Q3D MMF, 3-D CRMs are applied to the channel domains that extend over GCM grid cells. To avoid ""double counting"" of the large-scale effects, only the eddy effects simulated by the CRMs are implemented into the GCM as far as the transports are concerned, while the total effects are implemented for diabatic processes. The CRMs recognize the large-scale horizontal inhomogeneity through the lateral boundary conditions obtained from the GCM through interpolation. To maintain compatibility between the GCM and CRMs, the averages of CRM variables over the GCM grid spacing are relaxed to the corresponding GCM variables with the advective time scale. To evaluate the Q3D MMF, a transition from a wave to strong vortices is simulated in an idealized horizontal domain. Comparison with a fully 3-D benchmark simulation shows that the Q3D MMF successfully predicts the evolution of the vortices. It also captures important statistics such as the domain-averaged surface precipitation rate, turbulent fluxes and subgrid-scale (co)variances. From tests with 3-D and 2-D CRMs, respectively, it is concluded that the ability to recognize large-scale inhomogeneities is primarily responsible for the successful performance of the Q3D MMF. It is also demonstrated that the use of two perpendicular sets of CRMs has positive impacts on the simulation. Key Points Q3D MMF, a new generation of superparameterization, has been developed It is evaluated with simulations of tropical cyclone in an idealized domain Encouraging results suggest its potential for future NWP and climate models © 2014. American Geophysical Union. All Rights Reserved."
"56786162500;15130978400;55954056100;","Performance analysis of freeware filtering algorithms for determining ground surface from airborne laser scanning data",2014,"10.1117/1.JRS.8.083573","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84935844050&doi=10.1117%2f1.JRS.8.083573&partnerID=40&md5=8b3f4c1e34c75b1d3d2de5bd5e60b7ec","Numerous filtering algorithms have been developed in order to distinguish the ground surface from nonground points acquired by airborne laser scanning. These algorithms automatically attempt to determine the ground points using various features such as predefined parameters and statistical analysis. Their efficiency also depends on landscape characteristics. The aim of this contribution is to test the performance of six common filtering algorithms embedded in three freeware programs. The algorithms' adaptive TIN, elevation threshold with expand window, maximum local slope, progressive morphology, multiscale curvature, and linear prediction were tested on four relatively large (4 to 8 km2) and diverse landscape areas, which included steep sloped hills, urban areas, ridge-like eskers, and a river valley. The results show that in diverse test areas each algorithm yields various commission and omission errors. It appears that adaptive TIN is suitable in urban areas while the multiscale curvature algorithm is best suited in wooded areas. The multiscale curvature algorithm yielded the overall best results with average root-mean-square error values of 0.35 m. © 2014 Society of Photo-Optical Instrumentation Engineers."
"24069972000;7003557662;9239331500;7006864972;6701776280;","Adapting two-moment microphysics schemes across model resolutions: Subgrid cloud and precipitation fraction and microphysical sub-time step",2014,"10.1175/JAS-D-13-0367.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84903891963&doi=10.1175%2fJAS-D-13-0367.1&partnerID=40&md5=3490d7cfa0031176dac3ab4608c565d7","Two-moment multiclass microphysics schemes are very promising tools to be used in high-resolution NWP models. However, they must be adapted for coarser resolutions. Here, a twofold solution is proposed- namely, a simple representation of subgrid cloud and precipitation fraction-as well as a microphysical subtime- stepping method. The scheme is easy to implement, allows supersaturation in ice cloud, and exhibits flexibility for adoption across model grid spacing. It is implemented in the Milbrandt and Yau two-moment microphysics scheme with prognostic precipitation in the context of a simple 1D kinematic model as well as a mesoscale NWP model [the Canadian regional Global Environmental Multiscale model (GEM)]. Sensitivity tests were performed and the results highlighting the advantages and disadvantages of the two-moment multiclass cloud scheme relative to the classical Sundqvist scheme. The respective roles of subgrid cloud fraction, precipitation fraction, and time splitting were also studied. When compared to the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO)/CloudSat-retrieved cloud mask, cloud fraction, and ice water content, it is found that the proposed solutions significantly improve the behavior of the Milbrandt and Yau microphysics scheme at the regional NWP scale, suggesting that the subgrid cloud and precipitation fraction technique can be used across model resolutions. © 2014 American Meteorological Society."
"9241987300;7004978125;","Test models for filtering and prediction of moisture-coupled tropical waves",2013,"10.1002/qj.1956","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84873313708&doi=10.1002%2fqj.1956&partnerID=40&md5=24303dfc6423fadf20724cc4e1936e79","The filtering/data assimilation and prediction of moisture-coupled tropical waves is a contemporary topic with significant implications for extended-range forecasting. The development of efficient algorithms to capture such waves is limited by the unstable multiscale features of tropical convection which can organize large-scale circulations and the sparse observations of the moisture-coupled wave in both the horizontal and vertical. The approach proposed here is to address these difficult issues of data assimilation and prediction through a suite of analogue models which, despite their simplicity, capture key features of the observational record and physical processes in moisture-coupled tropical waves. The analogue models emphasized here involve the multicloud convective parametrization based on three cloud types (congestus, deep, and stratiform) above the boundary layer. Two test examples involving an MJO-like turbulent travelling wave and the initiation of a convectively coupled wave train are introduced to illustrate the approach. A suite of reduced filters with judicious model errors for data assimilation of sparse observations of tropical waves, based on linear stochastic models in a moisture-coupled eigenmode basis is developed here and applied to the two test problems. Both the reduced filter and 3D-Var with a full moist background covariance matrix can recover the unobserved troposphere humidity and precipitation rate; on the other hand, 3D-Var with a dry background covariance matrix fails to recover these unobserved variables. The skill of the reduced filtering methods in recovering the unobserved precipitation, congestus, and stratiform heating rates as well as the front-to-rear tilt of the convectively coupled waves exhibits a subtle dependence on the sparse observation network and the observation time. © 2012 Royal Meteorological Society."
"24536719900;6603315547;","Cirrus clouds triggered by radiation, a multiscale phenomenon",2010,"10.5194/acp-10-5179-2010","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77953497960&doi=10.5194%2facp-10-5179-2010&partnerID=40&md5=85e78e353326703dd71b6a69f3407f7a","In this study, the influence of radiative cooling and small eddies on cirrus formation is investigated. For this purpose the non-hydrostatic, anelastic model EULAG is used with a recently developed and validated ice microphysics scheme (Spichtinger and Gierens, 2009a). Additionally, we implemented a fast radiative transfer code (Fu et al., 1998). Using idealized profiles with high ice supersaturations up to 144% and weakly stable stratifications with Brunt-Vaisala frequencies down to 0.0018 s-1 within a supersaturated layer, the influence of radiation on the formation of cirrus clouds is remarkable. Due to the radiative cooling at the top of the ice supersaturated layer with cooling rates down to-3.5 K/d, the stability inside the ice supersaturated layer decreases with time. During destabilization, small eddies induced by Gaussian temperature fluctuations start to grow and trigger first nucleation. These first nucleation events then induce the growth of convective cells due to the radiative destabilization. The effects of increasing the local relative humidity by cooling due to radiation and adiabatic lifting lead to the formation of a cirrus cloud with IWC up to 33 mg/m3 and mean optical depths up to 0.36. In a more stable environment, radiative cooling is not strong enough to destabilize the supersaturated layer within 8 h; no nucleation occurs in this case. Overall triggering of cirrus clouds via radiation works only if the supersaturated layer is destabilized by radiative cooling such that small eddies can grow in amplitude and finally initialize ice nucleation. Both processes on different scales, small-scale eddies and large-scale radiative cooling are necessary. © Author(s) 2010."
"6507017020;7202208382;6701346974;","Implied ocean heat transports in the standard and superparameterized community atmospheric models",2010,"10.1175/2009JCLI2987.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77953723649&doi=10.1175%2f2009JCLI2987.1&partnerID=40&md5=0de7c1aa31087b1b2ee39487bc9a1815","Implied ocean heat transport (To) based on net surface energy budgets is computed for two versions of the Community Atmospheric Model (CAM, version 3.0) general circulation model (GCM). The first version is the standardCAMwith parameterized convection. The second is the multiscale modeling framework (MMF), in which parameterized convection is replaced with a two-dimensional cloud-resolving model in each GCM grid column. Although global-mean net surface energy totals are similar for both models, differences in the geographic distributions of the component errors lead to distinctly different To for each model, with CAM's To generally agreeing with observationally based To estimates, and the MMF's To producing northward transport at all latitudes north of ~50°S. Analysis of component error sources in the To calculation identifies needed improvements in the MMF. Net surface shortwave radiation and latent heat fluxes over the oceans are the primary causes of To errors in the MMF. Surface shortwave radiation biases in the MMF are associated with liquid and/or ice water content biases in tropical and extratropical convection and a deficit of marine stratocumulus clouds. It is expected that tropical ice water contents in the MMF can be made more realistic via improvements to the cloud microphysics parameterization. MMF marine stratocumulus clouds are overly sensitive to low-level relative humidity and form only with nearly saturated conditions and a shallow boundary layer. Latent heat flux errors in theMMFare amplifications of those found in theCAMand are concentrated in the trade wind regime and the Asian monsoon region and the adjacent western Pacific Ocean. Potential improvements to To are estimated by replacing either simulated net surface shortwave or latent heat fluxes with those from observations and recomputing To. When observed shortwave fluxes are used, both CAM and MMF produce greatly improved To curves for both hemispheres. When To is computed using observed latent heat fluxes, CAM To degrades slightly and MMF To improves, especially in the sign of Southern Hemisphere transport. © 2010 American Meteorological Society."
"7202422359;7202986331;13407438100;55823622600;","Treatment of clouds and the associated response of atmospheric sulfur in the Community Multiscale Air Quality (CMAQ) modeling system",2006,"10.1016/j.atmosenv.2006.05.069","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33749170984&doi=10.1016%2fj.atmosenv.2006.05.069&partnerID=40&md5=b413b6e5f09518794cbfb729e08794e6","An air quality modeling system-""Models-3/CMAQ""-is studied to determine the relationship between simulated cloud cover and atmospheric sulfur. Sulfur dioxide oxidation to sulfate occurs in the atmosphere through gas-phase reactions and reactions in clouds. The latter heterogeneous reactions can be rapid compared to gas-phase chemistry and a model must correctly simulate cloud cover to avoid serious bias. An evaluation of CMAQ revealed serious problems with diagnosed cloud cover and a bias in simulated sulfate production that was consistent with cloud biases. CMAQ modifications were tested to determine the sensitivity of the sulfur balance to cloud modeling assumptions. The model's vertical layer structure, limits on subgrid-scale cloud base and top heights, and the ability to simulate subgrid-scale convective cloud formation were found to be important. After applying model changes, atmospheric sulfur simulations were less biased and sulfur dioxide and sulfate were in better balance. © 2006 Elsevier Ltd. All rights reserved."
"56951139400;51864663400;56520921400;","Simultaneous characterization of mesoscale and convective-scale tropical rainfall extremes and their dynamical and thermodynamic modes of change",2017,"10.1002/2017MS001033","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85028930026&doi=10.1002%2f2017MS001033&partnerID=40&md5=1aca73ffd89116727c4e553af2304a7a","The Superparameterized Community Atmosphere Model (SPCAM) is used to identify the dynamical and organizational properties of tropical extreme rainfall events on two scales. We compare the mesoscales resolved by General Circulation Models (GCMs) and the convective scales resolved by Cloud-Resolving Models (CRMs) to reassess and extend on previous results from GCMs and CRMs in radiative-convective equilibrium. We first show that the improved representation of subgridscale dynamics in SPCAM allows for a close agreement with the 7%/K Clausius-Clapeyron rate of increase in mesoscale extremes rainfall rates. Three contributions to changes in extremes are quantified and appear consistent in sign and relative magnitude with previous results. On mesoscales, the thermodynamic contribution (5.8%/K) and the contribution from mass flux increases (2%/K) enhance precipitation rates, while the upward displacement of the mass flux profile (-1.1%/K) offsets this increase. Convective-scale extremes behave similarly except that changes in mass flux are negligible due to a balance between greater numbers of strong updrafts and downdrafts and lesser numbers of weak updrafts. Extremes defined on these two scales behave as two independent sets of rainfall events, with different dynamics, geometries, and responses to climate change. In particular, dynamic changes in mesoscale extremes appear primarily sensitive to changes in the large-scale mass flux, while the intensity of convective-scale extremes is not. In particular, the increases in mesoscale mass flux directly contribute to the intensification of mesoscale extreme rain, but do not seem to affect the increase in convective-scale rainfall intensities. These results motivate the need for better understanding the role of the large-scale forcing on the formation and intensification of heavy convective rainfall. © 2017. The Authors."
"57195219129;7101959253;55087038900;","The diurnal cycle of clouds and precipitation at the ARM SGP site: Cloud radar observations and simulations from the multiscale modeling framework",2017,"10.1002/2016JD026353","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85026310144&doi=10.1002%2f2016JD026353&partnerID=40&md5=1231c9867d15afd39ee98909c0bc6b56","Millimeter Wavelength Cloud Radar (MMCR) data from December 1996 to December 2010, collected at the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program Southern Great Plains (SGP) site, are used to examine the diurnal cycle of hydrometeor occurrence. These data are categorized into clouds (-40 dBZe ≤ reflectivity &lt; -10 dBZe), drizzle and light precipitation (-10 dBZe ≤ reflectivity &lt; 10 dBZe), and heavy precipitation (reflectivity ≥ 10 dBZe). The same criteria are implemented for the observation-equivalent reflectivity calculated by feeding outputs from a Multiscale Modeling Framework (MMF) climate model into a radar simulator. The MMF model consists of the National Center for Atmospheric Research Community Atmosphere Model with conventional cloud parameterizations replaced by a cloud-resolving model. We find that a radar simulator combined with the simple reflectivity categories can be an effective approach for evaluating diurnal variations in model hydrometeor occurrence. It is shown that the MMF only marginally captures observed increases in the occurrence of boundary layer clouds after sunrise in spring and autumn and does not capture diurnal changes in boundary layer clouds during the summer. Above the boundary layer, the MMF captures reasonably well diurnal variations in the vertical structure of clouds and light and heavy precipitation in the summer but not in the spring. © 2017. The Authors."
"57213357475;56530594900;57188729395;57217081805;16310345200;","A multiscale approach to assess geomorphological processes in a semiarid badland area (Ebro depression, Spain) [Análisis multiescala para estudiar procesos geomorfológicos en un área acarcavada de ambientes semiáridos (depresión del Ebro, España)]",2017,"10.18172/cig.3139","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85021806612&doi=10.18172%2fcig.3139&partnerID=40&md5=980deed9333525ffe371a2ffd46ea335","In this paper, three methods (Terrestrial Laser Scanner (TLS), terrestrial Structure from Motion photogrammetry (SfM) and aerial SfM photogrammetry with an Unmanned Aerial Vehicle (UAV)) were evaluated and compared to produce high resolution point clouds and Digital Elevation Models (DEMs) in a semiarid, complex badland area (Los Aguarales) with tourism activities. Geomorphological processes and dynamics were studied at different spatial scales. The preliminary results showed the possibilities of a multiscale approach, using various non-invasive techniques, to assess geomorphological processes. The high resolution of the point clouds, obtained with TLS and terrestrial SfM photogrammetry, allowed preliminary identification of numerous spatial details, although no relevant topographical changes were detected during a short, wet spring period (with rainfall of 200 mm). UAV images allowed work at larger scales (catchment), mapping piping features, and could be seen as a worthwhile tool for time-effective data acquisition from larger areas. The application of different technologies and a multiscale approach to generate high resolution DEMs is a useful technique when carrying out geomorphological studies in semiarid badland areas. However, long term studies will be necessary to verify the suitability of these techniques in such complex landscapes, and quantify topographical changes and erosion rates. Finally, the information obtained with these tools could be used to promote the study area as an interesting geomorphosite with opportunities for tourism. © Universidad de La Rioja."
"35784110200;55440121900;6701564951;6603687265;57202710955;57214486350;","THE PHYSICAL ENVIRONMENT AROUND IRAS 17599-2148: INFRARED DARK CLOUD and BIPOLAR NEBULA",2016,"10.3847/1538-4357/833/2/246","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85007566240&doi=10.3847%2f1538-4357%2f833%2f2%2f246&partnerID=40&md5=4e989e4d5cf92a3f53a803f9aaaf6d47","We present a multiscale and multiwavelength study to investigate the star formation process around IRAS 17599-2148, which is part of an elongated filamentary structure (EFS) (extension ∼21 pc) seen in the Herschel maps. Using the Herschel data analysis, at least six massive clumps (M clump ∼ 777-7024 M o) are found in the EFS with a range of temperature and column density of ∼16-39 K and ∼(0.6-11) ×1022 cm-2 (A V ∼ 7-117 mag), respectively. The EFS hosts cold gas regions (i.e., infrared dark cloud) without any radio detection and a bipolar nebula (BN) linked with the H ii region IRAS 17599-2148, tracing two distinct environments inferred through the temperature distribution and ionized emission. Based on virial analysis and higher values of self-gravitating pressure, the clumps are found unstable against gravitational collapse. We find 474 young stellar objects (YSOs) in the selected region, and ∼72% of these YSOs are found in the clusters distributed mainly toward the clumps in the EFS. These YSOs might have spontaneously formed due to processes not related to the expanding H ii region. At the edges of BN, four additional clumps are also associated with YSO clusters, which appear to be influenced by the expanding H ii region. The most massive clump in the EFS contains two compact radio sources traced in the Giant Metre-wave Radio Telescope 1.28 GHz map and a massive protostar candidate, IRS1, prior to an ultracompact H ii phase. Using the Very Large Telescope/NACO near-infrared images, IRS 1 is resolved with a jet-like feature within a 4200 au scale. © 2016. The American Astronomical Society. All rights reserved."
"8305662300;7401868458;","Response of moist convection to multi-scale surface flux heterogeneity",2016,"10.1002/qj.2811","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84971231458&doi=10.1002%2fqj.2811&partnerID=40&md5=acc755f0bbcb7bfc04be7d74bd369f4b","We investigate the response of moist convection to the spatial variation of surface sensible heat flux (SHF) in a mesoscale domain during the evolution of the afternoon convective boundary layer (CBL), using large-eddy simulation. The surface SHF heterogeneity in the domain is analytically created as a function of the spectral slope in the wavelength range from a few tens of kilometres to a few hundreds of metres in the SHF spectrum on a log–log scale. Assuming surface energy balance and spatially uniform available energy, the prescribed SHF has a phase lag of 180° with respect to the latent heat flux (LHF) in the domain. Two sets of three simulations are forced by heterogeneous surface SHF fields, which are characterized by similar statistics. One set, however, is created with a spectral slope of k-3. (where k. is wave number) and the other with a slope of k-2.. All of the simulations are integrated with the same observation-based initial sounding favourable for moist convection. In all of the k-3. -slope cases, early non-precipitating shallow clouds further develop into deep thunderstorms. But in all of the k-2 -slope cases, only shallow clouds develop. A key process in the transition to deep convection is the formation of a mesoscale pool of cool and moist air just above the top of the CBL. This high relative humidity (RH) pool is formed by repeated deep penetrations of turbulent plumes into the free atmosphere over a mesoscale surface of high SHF. These cross-scale fluxes, the vertical transports of mesoscale moisture and heat fluctuations by turbulent updraughts, are critical for the formation of the mesoscale pool of high RH. However, these cross-scale fluxes are cancelled out in the process of averaging, and thus appear negligible in the vertical profiles of domain-averaged moisture and heat fluxes. © 2016 Royal Meteorological Society"
"55017656900;7006840372;7403959083;7103365606;6603019866;57077016100;55232438500;7003527377;56037554100;6603440494;6602243107;","Real-time applications of the variational version of the local analysis and prediction system (vLAPS)",2015,"10.1175/BAMS-D-13-00185.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84955465533&doi=10.1175%2fBAMS-D-13-00185.1&partnerID=40&md5=0e9774817304fea759b1f9cb1b8f498a","NOAA/Earth System Research Laboratory (ESRL)/ Global Systems Division (GSD) introduced a new version of LAPS, called variational Local Analysis and Prediction System (vLAPS). The vLAPS uses a modern three-dimensional (3D) variational data assimilation (3DVAR) approach, based on a computationally efficient multigrid technique. An important feature of vLAPS is that the multiscale technique is applied in both space and time. In space, the largest scale features are analyzed first, followed by the addition of finer spatial scale details in successive iterations. In time, multiple time frames are analyzed in a single minimization, allowing the extraction of information from frequent observations related to rapid changes. As an NWP data assimilation system, the vLAPS integrates information from a wide variety of global, national, and local datasets, and short-range NWP forecast fields. Recently, the vLAPS software was expanded with a ray-tracing procedure to construct simulated all-sky cloud imagery produced by the LAPS 3D cloud analysis, and vLAPS/ARW forecasts."
"56000281400;","Mountain weather: Observation and modeling",2015,"10.1016/bs.agph.2015.01.001","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84928215734&doi=10.1016%2fbs.agph.2015.01.001&partnerID=40&md5=fcd2cb47437528056a8e78d08bb22d1c","Mountains, through atmospheric processes, play an integrated role in weather systems and climate systems. In turn, weather and climate over and nearby mountains are modified depending on environmental conditions. Mountain size, shape, slope, aspect ratio, and orientation along the water sources affect the weather systems; they can intensify fronts, eddies, vortex, rotors and turbulence, visibility, and precipitation. Depending on their location and height, precipitation type as snow over the mountains contributes significantly to hydrometeorological cycle and ecosystem. Increasing temperatures because of a possible climate change can reduce river discharges during warm seasons. Therefore, accurate measurements of climate change impact on the mountains are required. On the other hand, obtaining measurements over the mountainous regions are extremely difficult because of strong winds, cold temperatures (<0°C), mountain slopes, and heavy snow precipitation as well as instrumental issues. New developments on measurement strategies and instruments, and developing multiscale numerical models with detailed cloud microphysical processes and boundary layer parameterizations can reduce uncertainties in the weather and climate prediction. In this review, the challenges related to collecting measurements, numerical model predictions, and climate change issues over and nearby mountains will be emphasized. © 2015 Elsevier Inc."
"54398596200;55754495900;7404976222;","Impact of subdaily air-sea interaction on simulating intraseasonal oscillations over the tropical Asian monsoon region",2015,"10.1175/JCLI-D-14-00407.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84923039962&doi=10.1175%2fJCLI-D-14-00407.1&partnerID=40&md5=ac98de7176c5def691075260f138e21b","The off-equatorial boreal summer intraseasonal oscillation (ISO) is closely linked to the onset, active, and break phases of the tropical Asian monsoon, but the accurate simulation of the eastward-propagating lowfrequency ISO by current models remains a challenge. In this study, an atmospheric general circulation model (AGCM)-ocean mixed layer coupled model with high (10 min) coupling frequency (DC_10m) shows improved skill in simulating the ISO signal in terms of period, intensity, and propagation direction, compared with the coupled runs with low (1 and 12 h) coupling frequency and a stand-alone AGCM driven by the daily sea surface temperature (SST) fields. In particular, only the DC_10m is able to recreate the observed lead-lag phase relationship between SST (SST tendency) and precipitation at intraseasonal time scales, indicating that the ISO signal is closely linked to the subdaily air-sea interaction. During the ISO life cycle, air-sea interaction reduces the SST underlying the convection via wind-evaporation and cloud-radiation feedbacks, as well as wind-induced oceanic mixing, which in turn restrains convection. However, to the east of the convection, the heat-induced atmospheric Gill-type response leads to downward motion and a reduced surface westerly background flow because of the easterly anomalies. The resultant decreased oceanic mixing, together with the increased shortwave flux, tends to warm the SST and subsequently trigger convection. Therefore, the eastward-propagating ISO may result from an asymmetric east-west change in SST induced mainly by multiscale air-sea interactions. © 2015 American Meteorological Society."
"56520572300;56162305900;7103158465;55411439700;56384704800;55717074000;9249239700;","Investigating ice nucleation in cirrus clouds with an aerosol-enabled Multiscale Modeling Framework",2014,"10.1002/2014MS000343","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84923083516&doi=10.1002%2f2014MS000343&partnerID=40&md5=0c9316cc2e0e756b1dc72bee87c90b99","In this study, an aerosol-dependent ice nucleation scheme has been implemented in an aerosol-enabled Multiscale Modeling Framework (PNNL MMF) to study ice formation in upper troposphere cirrus clouds through both homogeneous and heterogeneous nucleation. The MMF model represents cloud scale processes by embedding a cloud-resolving model (CRM) within each vertical column of a GCM grid. By explicitly linking ice nucleation to aerosol number concentration, CRM-scale temperature, relative humidity and vertical velocity, the new MMF model simulates the persistent high ice supersaturation and low ice number concentration (10-100/L) at cirrus temperatures. The new model simulates the observed shift of the ice supersaturation PDF toward higher values at low temperatures following the homogeneous nucleation threshold. The MMF model predicts a higher frequency of midlatitude supersaturation in the Southern Hemisphere and winter hemisphere, which is consistent with previous satellite and in situ observations. It is shown that compared to a conventional GCM, the MMF is a more powerful model to simulate parameters that evolve over short time scales such as supersaturation. Sensitivity tests suggest that the simulated global distribution of ice clouds is sensitive to the ice nucleation scheme and the distribution of sulfate and dust aerosols. Simulations are also performed to test empirical parameters related to auto-conversion of ice crystals to snow. Results show that with a value of 250 μm for the critical diameter, Dcs, that distinguishes ice crystals from snow, the model can produce good agreement with the satellite-retrieved products in terms of cloud ice water path and ice water content, while the total ice water is not sensitive to the specification of Dcs value. © 2014. The Authors."
"23099339900;8670472000;7003557662;23571234400;","On the relationship between cloud-radiation interaction, atmospheric stability and Atlantic tropical cyclones in a variable-resolution climate model",2013,"10.1007/s00382-012-1311-6","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84874330414&doi=10.1007%2fs00382-012-1311-6&partnerID=40&md5=846fa739e46deefc995582cb6c932b85","We compare two 28-year simulations performed with two versions of the Global Environmental Multiscale model run in variable-resolution mode. The two versions differ only by small differences in their radiation scheme. The most significant modification introduced is a reduction in the ice effective radius, which is observed to increase absorption of upwelling infrared radiation and increase temperature in the upper troposphere. The resulting change in vertical lapse rate is then observed to drive a resolution-dependent response of convection, which in turn modifies the zonal circulation and induces significant changes in simulated Atlantic tropical cyclone activity. The resulting change in vertical lapse rate and its implication in the context of anthropogenic climate change are discussed. © 2012 The Author(s)."
"7202422359;55823622600;36178244200;","Modeling natural emissions in the Community Multiscale Air Quality (CMAQ) model - Part 2: Modifications for simulating natural emissions",2011,"10.5194/acp-11-293-2011","https://www.scopus.com/inward/record.uri?eid=2-s2.0-78651506764&doi=10.5194%2facp-11-293-2011&partnerID=40&md5=cbc03dac17f4757c0b0047fc6838208b","The Community Multiscale Air Quality (CMAQ) model version 4.6 has been revised with regard to the representation of chlorine (HCl, ClNO2) and sulfur (dimethylsulfide, or DMS, and H2S), and evaluated against observations and earlier published models. Chemistry parameterizations were based on published reaction kinetic data and a recently developed cloud chemistry model that includes heterogeneous reactions of organic sulfur compounds. Evaluation of the revised model was conducted using a recently enhanced data base of natural emissions that includes ocean and continental sources of DMS, H2S, chlorinated gases and lightning NOx for the continental United States and surrounding regions. Results using 2002 meteorology and emissions indicated that most simulated ""natural"" (plus background) chemical and aerosol species exhibit the expected seasonal variations at the surface. Ozone exhibits a winter and early spring maximum consistent with ozone data and an earlier published model. Ozone distributions reflect the influences of atmospheric dynamics and pollutant background levels imposed on the CMAQ simulation by boundary conditions derived from a global model. A series of model experiments reveals that the consideration of gas-phase organic sulfur chemistry leads to sulfate aerosol increases over most of the continental United States. Cloud chemistry parameterization changes result in widespread decreases in SO2 across the modeling domain and both increases and decreases in sulfate. Most cloud-mediated sulfate increases occurred mainly over the Pacific Ocean (up to about 0.1 μg m-3) but also over and downwind from the Gulf of Mexico (including parts of the eastern US). Geographic variations in simulated SO2 and sulfate are due to the link between DMS/H2S and their byproduct SO2, the heterogeneity of cloud cover and precipitation (precipitating clouds act as net sinks for SO2 and sulfate), and the persistence of cloud cover (the largest relative sulfate increases occurred over the persistently cloudy Gulf of Mexico and western Atlantic Ocean). Overall, the addition of organic sulfur chemistry increased hourly surface sulfate levels by up to 1-2 μg m-3 but reduced sulfate levels in the vicinity of high SO2 emissions (e.g., wildfires). Simulated surface levels of DMS compare reasonably well with observations in the marine boundary layer where DMS oxidation product levels are lower than observed. This implies either a low bias in model oxidation rates of organic sulfur species or a low bias in the boundary conditions for DMS oxidation products. This revised version of CMAQ provides a tool for realistically simulating the influence of natural emissions on air quality. © 2011 Author(s)."
"6602563767;57210074890;","Classification of thunderstorms over India using multiscale analysis of AMSU-B images",2004,"10.1175/1520-0450(2004)043<0595:COTOIU>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-2342648770&doi=10.1175%2f1520-0450%282004%29043%3c0595%3aCOTOIU%3e2.0.CO%3b2&partnerID=40&md5=44efce5328f9d5a4e143584ca14fa0fa","The structure of thunderstorms has been studied for a long time. In the absence of radar coverage, only high-resolution multifrequency satelliteborne sensors of longer wavelengths (i.e., microwaves) can show structures inside thunderstorms. The National Oceanic and Atmospheric Administration (NOAA) Advanced Microwave Sounding Unit-B (AMSU-B), with five frequencies and 16-km resolution, is now capable of looking at thunderstorm structure. To analyze cloud structure, a tool that can separate regions by size is needed. The à trous wavelet transform, a discrete approximation to the continuous wavelet transform, is such a tool. Images, as well as their wavelet components, may be noisy. To remove noise from wavelet components, those smaller than one standard deviation (of the wavelet image) are equated to zero. This is most suitable for meteorological studies. Images at an appropriate wavelet scale are used for the analysis of thunderstorms. Thunderstorm structures show mostly in scales 2 and 3 (sizes less than 32 and 64 km, respectively) of the à trous transformed images. Other cloud classes are seen either in smaller or larger scales. Given the resolution of the images, three parts of the thunderstorms, namely, the cumulonimbus towers, detraining altostratus, and cirrus anvils, are separated. Thunderstorms in the Indian subcontinent and adjoining seas are grouped according to six classes of wind profiles obtained in this region. Different organizations of towers, altostratus, and cirrus anvils emerged in the AMSU-B images of these six classes. © 2004 American Meteorological Society."
"6507185657;57203400519;7003398947;7004838908;","Windowed and wavelet analysis of marine stratocumulus cloud inhomogeneity",1995,"10.1175/1520-0469(1995)052<3013:WAWAOM>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029414014&doi=10.1175%2f1520-0469%281995%29052%3c3013%3aWAWAOM%3e2.0.CO%3b2&partnerID=40&md5=0000dfdf45ac6c43489d537474feaab3","To improve radiative transfer calculations for inhomogeneous clouds, a consistent means of modeling inhomogeneity is needed. One current method of modeling cloud inhomogeneity is through the use of fractal parameters. This method is based on the supposition that cloud inhomogeneity over a large range of scales is related. An analysis technique named wavelet analysis provides a means of studying the multiscale nature of cloud inhomogeneity. In this paper, the authors discuss the analysis and modeling of cloud inhomogeneity through the use of wavelet analysis. Wavelet analysis as well as other windowed analysis techniques are used to study liquid water path (LWP) measurements obtained during the marine stratocumulus phase of the First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment. -from Authors"
"36124576800;57203579757;57193856591;37861012100;","Comparing the assimilation of radar reflectivity using the direct GSI-based Ensemble-Variational (EnVar) and indirect cloud analysis methods in convection-allowing forecasts over the continental United States",2019,"10.1175/MWR-D-18-0171.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85065827978&doi=10.1175%2fMWR-D-18-0171.1&partnerID=40&md5=426123a8f39ae0058bdeac1d2d8f2349","Two methods for assimilating radar reflectivity into deterministic convection-allowing forecasts were compared: an operationally used, computationally less expensive cloud analysis (CA) scheme and a relatively more expensive, but rigorous, ensemble Kalman filter-variational hybrid method (EnVar). These methods were implemented in the Nonhydrostatic Multiscale Model on the B-grid and were tested on 10 cases featuring high-impact deep convective storms and heavy precipitation. A variety of traditional, neighborhood-based, and features-based verification metrics support that the EnVar produced superior free forecasts compared to the CA procedure, with statistically significant differences extending up to 9 h into the forecast. Despite being inferior, the CA scheme was able to provide benefit compared to not assimilating radar reflectivity at all, but limited to the first few forecast hours. While the EnVar is able to partially suppress spurious convection by assimilating 0-dBZ reflectivity observations directly, the CA is not designed to reduce or remove hydrometeors. As a result, the CA struggles more with suppression of spurious convection in the first-guess field, which resulted in high-frequency biases and poor forecast evolution, as illustrated in a few case studies. Additionally, while the EnVar uses flow-dependent ensemble covariances to update hydrometers, thermodynamic, and dynamic variables simultaneously when the reflectivity is assimilated, the CA relies on a radar reflectivity-derived latent heating rate that is applied during a separate digital filter initialization (DFI) procedure to introduce deep convective storms into the model, and the results of CA are shown to be sensitive to the window length used in the DFI. © 2019 American Meteorological Society."
"55214935900;57208751912;56541934100;56621591000;27169720300;26661399000;","Building extraction from UAV images jointly using 6D-SLIC and Multiscale Siamese Convolutional Networks",2019,"10.3390/rs11091040","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85065748352&doi=10.3390%2frs11091040&partnerID=40&md5=c042107469f3f03361347a6ca43b7c71","Automatic building extraction using a single data type, either 2D remotely-sensed images or light detection and ranging 3D point clouds, remains insufficient to accurately delineate building outlines for automatic mapping, despite active research in this area and the significant progress which has been achieved in the past decade. This paper presents an effective approach to extracting buildings from Unmanned Aerial Vehicle (UAV) images through the incorporation of superpixel segmentation and semantic recognition. A framework for building extraction is constructed by jointly using an improved Simple Linear Iterative Clustering (SLIC) algorithm and Multiscale Siamese Convolutional Networks (MSCNs). The SLIC algorithm, improved by additionally imposing a digital surface model for superpixel segmentation, namely 6D-SLIC, is suited for building boundary detection under building and image backgrounds with similar radiometric signatures. The proposed MSCNs, including a feature learning network and a binary decision network, are used to automatically learn a multiscale hierarchical feature representation and detect building objects under various complex backgrounds. In addition, a gamma-transform green leaf index is proposed to truncate vegetation superpixels for further processing to improve the robustness and efficiency of building detection, the Douglas-Peucker algorithm and iterative optimization are used to eliminate jagged details generated from small structures as a result of superpixel segmentation. In the experiments, the UAV datasets, including many buildings in urban and rural areas with irregular shapes and different heights and that are obscured by trees, are collected to evaluate the proposed method. The experimental results based on the qualitative and quantitative measures confirm the effectiveness and high accuracy of the proposed framework relative to the digitized results. The proposed framework performs better than state-of-the-art building extraction methods, given its higher values of recall, precision, and intersection over Union (IoU). © 2019 by the authors."
"55644317800;57205742028;36835970800;12141267000;55768476100;","Reconstructing geostationary satellite land surface temperature imagery based on a multiscale feature connected convolutional neural network",2019,"10.3390/rs11030300","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85061348408&doi=10.3390%2frs11030300&partnerID=40&md5=be4bc0d42b903ac0e675b217fdabbdf6","Geostationary satellite land surface temperature (GLST) data are important for various dynamic environmental and natural resource applications for terrestrial ecosystems. Due to clouds, shadows, and other atmospheric conditions, the derived LSTs are often missing a large number of values. Reconstructing the missing values is essential for improving the usability of the geostationary satellite LST data. However, current reconstruction methods mainly aim to fill the values of a small number of invalid pixels with many valid pixels, which can provide useful land surface temperature values. When the missing data extent becomes large, the reconstruction effect will worsen because the relationship between different spatiotemporal geostationary satellite LSTs is complex and highly nonlinear. Inspired by the superiority of the deep convolutional neural network (CNN) in solving highly nonlinear and dynamic problems, a multiscale feature connection CNN model is proposed to fill missing LSTs with large missing regions. The proposed method has been tested on both FengYun-2G and Meteosat Second Generation-Spinning Enhanced Visible and InfraRed Imager geostationary satellite LST datasets. The results of simulated and actual experiments show that the proposed method is accurate to within about 1 °C, with 70% missing data rates. This is feasible and effective for large regions of LST reconstruction tasks. © 2019 by the authors."
"51864663400;23991212200;7004479957;55232897900;6602878057;6701346974;55544607500;","Insensitivity of the Cloud Response to Surface Warming Under Radical Changes to Boundary Layer Turbulence and Cloud Microphysics: Results From the Ultraparameterized CAM",2018,"10.1029/2018MS001409","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85058702303&doi=10.1029%2f2018MS001409&partnerID=40&md5=3632887d08c1d53eac968ed95a206f7c","We study the cloud response to a +4K surface warming in a new multiscale climate model that uses enough interior resolution to begin explicitly resolving boundary layer turbulence (i.e., ultraparameterization or UP). UP's predictions are compared against those from standard superparameterization (SP). The mean cloud radiative effect feedback turns out to be remarkably neutral across all of our simulations, despite some radical changes in both cloud microphysical parameter settings and cloud-resolving model grid resolution. The overall low cloud response to warming is a positive low cloud feedback over land, a negative feedback (driven by cloud optical depth increase) at high latitudes, and weak feedback over the low-latitude oceans. The most distinct effects of UP result from tuning decisions impacting high-latitude cloud feedback. UP's microphysics is tuned to optimize the model present-day, top-of-atmosphere radiation fluxes against CERES observations, by lowering the cloud ice-liquid phase shift temperature ramp, adjusting the ice/liquid autoconversion rate, and increasing the ice fall speed. This reduces high-latitude low cloud amounts and damps the optical depth feedback at high latitudes, leading to a slightly more positive global cloud feedback compared to SP. A sensitivity test that isolates these microphysical impacts from UP's grid resolution confirms that the microphysical settings are mostly responsible for the differences between SP and UP cloud feedback. ©2018. The Authors."
"56448302000;6603263640;7202048112;7404970050;","Multiscale atmospheric overturning of the Indian summer monsoon as seen through isentropic analysis",2018,"10.1175/JAS-D-18-0068.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85052610994&doi=10.1175%2fJAS-D-18-0068.1&partnerID=40&md5=61b460b7386c65f5351312b9550b58b6","This study investigates multiscale atmospheric overturning during the 2009 Indian summer monsoon (ISM) using a cloud-permitting numerical model. The isentropic analysis technique adopted here sorts vertical mass fluxes in terms of the equivalent potential temperature of air parcels, which is capable of delineating the atmospheric overturning between ascending air parcels with high entropy and subsiding air parcels with low entropy. The monsoonal overturning is further decomposed into contributions from three characteristic scales: the basinwide ascent over the Indian monsoon domain, the regional-scale overturning associated with synoptic and mesoscale systems, and the convective-scale overturning. Results show that the convective-scale component dominates the upward mass transport in the lower troposphere while the region-scale component plays an important role by deepening the monsoonal overturning. The spatial variability of the convective-scale overturning is analyzed, showing intense convection over the Western Ghats and the Bay of Bengal while the deepest overturning is localized over northern India and the Himalayan foothills. The equivalent potential temperature in convective updrafts is higher over land than over the ocean or coastal regions. There is also substantial variability in the atmospheric overturning associated with the intraseasonal variability. The upward mass and energy transport increase considerably during the active phases of the ISM. A clear northeastward propagation in the peak isentropic vertical mass and energy transport over different characteristic regions can be found during the ISM, which corresponds to the intraseasonal oscillations of the ISM. Altogether, this study further demonstrates the utility of the isentropic analysis technique to characterize the spatiotemporal variations of convective activities in complex atmospheric flows. © 2018 American Meteorological Society."
"34872128700;6603552698;57213873447;","A parallel N-dimensional Space-Filling Curve library and its application in massive point cloud management",2018,"10.3390/ijgi7080327","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051709103&doi=10.3390%2fijgi7080327&partnerID=40&md5=f5f946bd89cd629a4c9893739d650f67","Because of their locality preservation properties, Space-Filling Curves (SFC) have been widely used in massive point dataset management. However, the completeness, universality, and scalability of current SFC implementations are still not well resolved. To address this problem, a generic n-dimensional (nD) SFC library is proposed and validated in massive multiscale nD points management. The library supports two well-known types of SFCs (Morton and Hilbert) with an object-oriented design, and provides common interfaces for encoding, decoding, and nD box query. Parallel implementation permits effective exploitation of underlying multicore resources. During massive point cloud management, all xyz points are attached an additional random level of detail (LOD) value l. A unique 4D SFC key is generated from each xyzl with this library, and then only the keys are stored as flat records in an Oracle Index Organized Table (IOT). The key-only schema benefits both data compression and multiscale clustering. Experiments show that the proposed nD SFC library provides complete functions and robust scalability for massive points management. When loading 23 billion Light Detection and Ranging (LiDAR) points into an Oracle database, the parallel mode takes about 10 h and the loading speed is estimated four times faster than sequential loading. Furthermore, 4D queries using the Hilbert keys take about 1∼5 s and scale well with the dataset size. © 2018 by the authors."
"25941200000;57195576398;56009810800;35317714900;9239331500;7003557662;","Scaling properties of observed and simulated satellite visible radiances",2017,"10.1002/2017JD027146","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85028937797&doi=10.1002%2f2017JD027146&partnerID=40&md5=ada80f879f83479097e98195312f394c","Structure functions Sq, which are related to power spectra and used to study turbulence, were computed for GOES-13 visible radiances measured on 16 May 2015 over French Guiana and adjacent Atlantic Ocean. The nested Global Environmental Multiscale (GEM) numerical weather prediction (NWP) model was run for the same time and area. Cloud data generated by GEM over (300 km)2 domains, with one-way nesting ending at horizontal grid-spacing of 0.25 km, were operated on by a 3-D solar radiative transfer model with resulting radiances degraded to GOES-13 resolution (~1 km) and Sq computed for them, too. For GOES-13 radiances, scaling exponents ζ(2) associated with S2, for separation distances between 5 km and 25 km, were typically &gt;0.6 for deep convective and marine boundary layer clouds and &lt;0.4 for shallow cumuli over land. ζ(2) for GEM agreed well with GOES-13 for deep convective clouds. This suggests that the self-organizing properties of deep convection in GEM exhibit realistic geometric features, a potentially important point given the link between cloud structure and precipitation, with the latter being much more difficult to measure and assess than visible radiances. Regarding radiances for GEM's marine boundary layer clouds, their Sq differed markedly from GOES-13's; better resembling fair-weather cumulus. Likewise, GEM's shallow cumuli over land appear to have bypassed the “scattered” fair-weather stage and went straight into more organized convection. Thus, it appears that comparing time series of Sq for geostationary satellite data and corresponding modeled radiances has the potential to benefit assessment of cloud system-resolving models. ©2017 Her Majesty the Queen in Right of Canada. Reproduced with the permission of the Minister of Environment."
"7202772927;7101801476;","The impact of simulated mesoscale convective systems on global precipitation: A multiscale modeling study",2017,"10.1002/2016MS000836","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85017181738&doi=10.1002%2f2016MS000836&partnerID=40&md5=aee89950ae89e430182f81cc24e89320","The importance of precipitating mesoscale convective systems (MCSs) has been quantified from TRMM precipitation radar and microwave imager retrievals. MCSs generate more than 50% of the rainfall in most tropical regions. MCSs usually have horizontal scales of a few hundred kilometers (km); therefore, a large domain with several hundred km is required for realistic simulations of MCSs in cloud-resolving models (CRMs). Almost all traditional global and climate models do not have adequate parameterizations to represent MCSs. Typical multiscale modeling frameworks (MMFs) may also lack the resolution (4 km grid spacing) and domain size (128 km) to realistically simulate MCSs. The impact of MCSs on precipitation is examined by conducting model simulations using the Goddard Cumulus Ensemble (GCE, a CRM) model and Goddard MMF that uses the GCEs as its embedded CRMs. Both models can realistically simulate MCSs with more grid points (i.e., 128 and 256) and higher resolutions (1 or 2 km) compared to those simulations with fewer grid points (i.e., 32 and 64) and low resolution (4 km). The modeling results also show the strengths of the Hadley circulations, mean zonal and regional vertical velocities, surface evaporation, and amount of surface rainfall are weaker or reduced in the Goddard MMF when using more CRM grid points and higher CRM resolution. In addition, the results indicate that large-scale surface evaporation and wind feedback are key processes for determining the surface rainfall amount in the GMMF. A sensitivity test with reduced sea surface temperatures shows both reduced surface rainfall and evaporation. © 2017. The Authors."
"57201893947;50660941400;55486059500;57193518068;57192575388;35115110600;35114477500;","Airborne laser scanning point clouds filtering method based on the construction of virtual ground seed points",2017,"10.1117/1.JRS.11.016032","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85014530949&doi=10.1117%2f1.JRS.11.016032&partnerID=40&md5=4d90dc81562a04b496329bf553986d3b","Filtering of airborne laser scanning (ALS) point clouds into ground and nonground points is a core postprocessing step for ALS data. A hierarchical filtering method, which has high operating efficiency and accuracy because of the combination of multiscale morphology and progressive triangulated irregular network (TIN) densification (PTD), is proposed. In the proposed method, the grid is first constructed for the ALS point clouds, and virtual seed points are set by analyzing the shape and elevation distribution of points within the grid. Then, the virtual seed points are classified as ground or nonground using the multiscale morphological method. Finally, the virtual ground seed points are utilized to generate the initial TIN, and the filter is completed by iteratively densifying the initial TIN. We used various ALS data to test the performance of the proposed method. The experimental results show that the proposed filtering method has strong applicability for a variety of landscapes and, in particular, has lower commission error than the classical PTD filtering method in urban areas. © 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)."
"56681764600;8701353900;","Identifying sensitivities for cirrus modelling using a two-moment two-mode bulk microphysics scheme",2015,"10.3402/tellusb.v67.24494","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84930959764&doi=10.3402%2ftellusb.v67.24494&partnerID=40&md5=1f71aa7408eec96f4907a85550ffaf92","Cirrus cloud genesis is an inherently multiscale and non-linear problem. The synoptic scale provides the environment, the mesoscale determines the forcing and the actual nucleation events occur on a microscopic scale. This makes the parameterisation in numerical weather prediction models a challenging task. In order to improve the prediction of cirrus clouds and ice supersaturation formation in the German Weather Service (DWD) model chain, the controlling physical processes are investigated and parameterised in a new cloud ice microphysics scheme. The new scheme is an extended version of the ice-microphysical scheme operational in the numerical weather prediction models of DWD. The developed two-moment two-mode cloud ice scheme includes state-of-the-art parameterisations for the two main processes for ice formation, namely homogeneous and heterogeneous nucleation. Homogeneous freezing of supercooled liquid aerosols is triggered in regions with high atmospheric ice supersaturations (145-160%) and high cooling rates. Atmospheric small-scale fluctuations are accounted for by use of the turbulent kinetic energy. Heterogeneous nucleation depends mostly on the existence of ice nuclei in the atmosphere and occurs primarily at lower ice supersaturations. Thus, heterogeneously nucleated ice crystals deplete ice supersaturation via depositional growth and can therefore inhibit subsequent homogeneous freezing. The new cloud ice scheme accounts for pre-existing ice crystals, contains a prognostic budget variable for activated ice nuclei and includes cloud ice sedimentation. Furthermore, a consistent treatment of the depositional growth of the two-ice particle modes and the larger snowflakes is applied by using a relaxation time scale method which ensures a physical representation for depleting ice supersaturation. The new cloud ice scheme is used to identify the relative roles of heterogeneous and homogeneous nucleation in the formation of cirrus clouds and ice supersaturation. A parcel model is used in order to investigate the differences between the operational and new cloud ice scheme. The time scales for the homogeneous nucleation event and for the depositional growth are emphasised. The importance of the new ice nucleation scheme is demonstrated by conducting idealised simulations of orographic cirrus in the COSMO (Consortium for Small-Scale Modeling) model environment. © 2015 C. G. Kö hler and A. Seifert."
"7403052083;6701899848;16315767700;6603879058;","Coincident multiscale estimates of Arctic sea ice thickness",2012,"10.1029/2012EO060001","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84857081620&doi=10.1029%2f2012EO060001&partnerID=40&md5=e707b358e8e69aa10f41ae26dee937c1","Recent dramatic changes in the characteristics of the Arctic sea ice cover have sparked interest and concern from a wide range of disciplines including socioeconomics, maritime safety and security, and resource management, as well as basic research science. Though driven by different priorities, common to all is the demand for an improved ability to monitor and forecast changes in the sea ice cover. Key to meeting this demand is further improvement in the quality of observations collected from remote platforms. Satellites provide an important platform for instruments designed to monitor basin-wide changes in the volume of the ice cover, a function of ice extent and thickness. Remote techniques to monitor sea ice extent in all seasons are well developedthese observations reveal a dramatic decline in summer sea ice extent since 1979, when satellite records became available. Further, they indicate that the decline has been facilitated by a dramatic decrease in the extent of perennial (i.e., multiyear) ice. Combined estimates of ice thickness derived from submarine records between 1958 and 2000, and Ice, Cloud, and land Elevation Satellite (ICESat) laser altimetry from 2003 to 2008, provide the longest-term record of sea ice thickness observations. These data suggest a decrease in the mean overall thickness of the sea ice over a region covering about 38% of the Arctic Ocean."
"6506267500;7103259185;","Explicit forecasts of hail occurrence and expected hail size using the GEM-HAILCAST system with a rainfall filter",2009,"10.1175/2009WAF2222138.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-74549201539&doi=10.1175%2f2009WAF2222138.1&partnerID=40&md5=f63ffa58bb7e3b9a5b2090a3af3dac42","HAILCAST is a numerical model developed specifically to predict the size of the largest hail reaching the ground. It consists of a steady-state cloud model combined with a time-dependent hailstone growth model. The regional version of the Canadian Global Environmental Multiscale (GEM) model is used to provide prognostic model soundings that are used as input data for HAILCAST. A map of forecasted maximum hail size is thereby obtained. Because hail is typically accompanied by rain, it would be advantageous if the GEM-HAILCAST system were to predict the occurrence of hail only in those regions where the GEM model was predicting precipitation. Hence, the utility of applying a forecast rainfall mask from the GEM model to restrict hail forecasts to those areas where rainfall is forecast during a 12-h window centered on 0000 UTC was tested. The accumulated precipitation filter is objective and integrates both the thermodynamic and dynamic output from the GEM model over many time steps. To test the utility of applying the GEM forecast precipitation mask, the masking technique was applied to HAILCAST-predicted maximum hail size maps for the three Canadian prairie provinces between 1 June and 31 August 2000. Several case studies will be presented to illustrate the usefulness of adding the precipitation mask. Verification statistics confirm that applying the rainfall mask tends to slightly reduce the false alarm ratio while still identifying the majority of hail events within a special study area over southern Alberta. The performance of the precipitation masking technique was not as effective on severe hail days, especially when attempting to identify both the occurrence and location of severe hail swaths. © 2009 American Meteorological Society."
"57188723213;10141490000;7005364475;56270028800;57188724979;","Identifying asphalt pavement distress using UAV LiDAR point cloud data and random forest classification",2019,"10.3390/ijgi8010039","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85061377578&doi=10.3390%2fijgi8010039&partnerID=40&md5=7f71e16803fdb8310e7813c9090bf8a9","Asphalt pavement ages and incurs various distresses due to natural and human factors. Thus, it is crucial to rapidly and accurately extract different types of pavement distress to effectively monitor road health status. In this study, we explored the feasibility of pavement distress identification using low-altitude unmanned aerial vehicle light detection and ranging (UAV LiDAR) and random forest classification (RFC) for a section of an asphalt road that is located in the suburb of Shihezi City in Xinjiang Province of China. After a spectral and spatial feature analysis of pavement distress, a total of 48 multidimensional and multiscale features were extracted based on the strength of the point cloud elevations and reflection intensities. Subsequently, we extracted the pavement distresses from the multifeature dataset by utilizing the RFC method. The overall accuracy of the distress identification was 92.3%, and the kappa coefficient was 0.902. When compared with the maximum likelihood classification (MLC) and support vector machine (SVM), the RFC had a higher accuracy, which confirms its robustness and applicability to multisample and high-dimensional data classification. Furthermore, the method achieved an overall accuracy of 95.86% with a validation dataset. This result indicates the validity and stability of our method, which highway maintenance agencies can use to evaluate road health conditions and implement maintenance. © 2019 by the authors."
"15135583300;6603381720;","Relationships between electrification and storm-scale properties based on idealized simulations of an intensifying hurricane-like vortex",2018,"10.1175/JAS-D-17-0202.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042222077&doi=10.1175%2fJAS-D-17-0202.1&partnerID=40&md5=0c548e9a6385276dc8f1ffeed6db0585","This study investigates relationships between storm-scale properties and the electrification and lightning of two simulations of an intensifying idealized tropical cyclone (TC) using the cloud-resolving Collaborative Model for Multiscale Atmospheric Simulation (COMMAS). To produce an intensifying storm, an initial weak TC is subjected to a linear increase in sea surface temperature. As the TC intensifies, lightning flash rates increase in both the inner core (r ≤ 100 km) and outer region (100 &lt; r ≤ 300 km). As time progresses, lightning in the outer region gradually decreases, while the inner-core lightning remains relatively steady. Bootstrapped correlation statistics using 1000 random samples between the pressure trace and time series of lightning rates shows a statistically significant negative correlation between inner-core lightning and TC intensification. Lightning rates in the outer bands were found to lag minimum surface pressure by 12 h. The increases in lightning in both the inner core and outer region coincided well with increases in 0.5 g kg-1 graupel and 5 m s-1 updraft volumes in each respective region. Correlation statistics with selected kinematic and microphysical variables known to be associated with lightning in thunderstorms, such as the ice water path, integrated updraft volume, and graupel volume, revealed that their increase in the inner core indicated an ongoing deepening, similar to the lightning. Trends in these proxy variables in the outer bands were also found to lag TC intensification by 12 h. Overall, the best linear relationships with lightning in either the inner core or the outer region were obtained with the 0.5 g kg-1 graupel volume and total graupel mass. © 2018 American Meteorological Society."
"6603969535;57200410677;57200414403;57200416152;57200421154;57200410183;57191477224;","Temporal variability of the Charlotte (sub)urban heat Island",2018,"10.1175/JAMC-D-17-0099.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85041240186&doi=10.1175%2fJAMC-D-17-0099.1&partnerID=40&md5=40374111c0b70e7e85facde6fe97835b","A multiscale temporal analysis of the urban heat island (UHI) for a large, rapidly growing, subtropical city (Charlotte, North Carolina) is conducted using hourly surface observations from a regional network of 12 weather and air-quality stations over a 5-yr period and monthly mean surface temperatures from two stations over a 40-yr period. Each station was classified as urban, suburban, or rural after detailed site analysis. During the 5-yr period, from temperature differences between the most central urban site and the rural reference site, over 70% of nights exhibited prominent nocturnal UHIs. The most intense UHIs occurred on winter nights with light winds, clear skies, low humidity, strong low-level stability, and no precipitation or frontal passage. The UHI maxima occurred either just after sunset or near sunrise. Maximum urban and rural cooling rates occurred within a few hours of sunset, but rural maxima were larger and preceded (by 1-2 h) the urban maxima. Daily variations in nocturnal mean UHI intensity exhibited significant positive correlations with cloud-base height, atmospheric stability, NO2 concentration, and total solar radiation and significant negative correlations with relative humidity, wind speed, and cloud cover. When optimal weather for UHI development was present, UHIs were more intense on weekdays than on weekends. During the 40-yr period, an appreciable positive trend in UHI intensity occurred. These results support the notion that weather, air pollution, and urban form change can significantly modulate UHI intensities. Similarities and differences between the Charlotte UHI and those observed in similar cities are discussed. © 2018 American Meteorological Society."
"7407016988;7004369046;","Multiscale variability of the atmospheric boundary layer during DYNAMO",2017,"10.1175/JAS-D-17-0182.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85040366367&doi=10.1175%2fJAS-D-17-0182.1&partnerID=40&md5=864394a366075e384274eff1fc32285c","Properties of the atmospheric boundary layer (ABL) over the central Indian Ocean are investigated using sounding data obtained during the Dynamics of the MJO (DYNAMO) field campaign in 2011/12. Observations from Gan Island on Addu Atoll, the R/V Revelle, and Malé in the Maldives are used to determine the frequency of well-mixed layers and their mean thermodynamic and wind profiles. Well-mixed boundary layers or mixed layers were observed 68% of the time from the three sites, ranging from ~100-m depth in recovering convective downdraft wakes to ~925 m in undisturbed conditions, with a mean depth of 508 m. At Revelle, the site most representative of the open ocean, the ABL displayed a distinct signal of modulation by the October and November MJOs, with mixed-layer depths gradually increasing through the suppressed phases as the sea surface temperature (SST) increased leading up to the active phases, followed by frequent ABL stabilization and shallow mixed layers in recovering wakes. A distinct diurnal cycle of mixed-layer depths and properties was observed during the MJO suppressed phases in response to a diurnal cycle of the SST under the mostly light-wind, clear-sky conditions. The daytime growth of the mixed layer contributed to an afternoon maximum in cumulus cloud development and rainfall during the suppressed periods by allowing more boundary layer thermals to reach their condensation levels. The variability of the ABL on time scales ranging from convective to diurnal to monthly poses significant challenges for numerical simulations of the MJO and the tropical circulation in general. © 2017 American Meteorological Society."
"56567123500;36071914900;18538349400;","Application in Feature Extraction of AE Signal for Rolling Bearing in EEMD and Cloud Similarity Measurement",2015,"10.1155/2015/752078","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84941671053&doi=10.1155%2f2015%2f752078&partnerID=40&md5=93435e8549ebea701fdec5ebe3c5a7ce","Due to the powerful ability of EEMD algorithm in noising, it is usually applied to feature extraction of fault signal of rolling bearing. But the selective correctness of sensitive IMF after decomposition can directly influence the correctness of feature extraction of fault signal. In order to solve the problem, the paper firstly proposes a new method on selecting sensitive IMF based on Cloud Similarity Measurement. By comparing this method in simulation experiment with the traditional mutual information method, it is obvious that the proposed method has overcome the misjudgment in the traditional method and it has higher accuracy, by factually collecting the normal, damage, and fracture fault AE signal of the inner ring of rolling bearing as samples, which will be decomposed by EEMD algorithm in the experiments. It uses Cloud Similarity Measurement to select sensitive IMF which can reflect the fault features. Finally, it sets the Multivariate Multiscale Entropy (MME) of sensitive IMF as the eigenvalue of original signal; then it is classified by the SVM to determine the fault types exactly. The results of the experiments show that the selected sensitive IMF based on Cloud Similarity Measurement is effective; it can help to improve the accuracy of the fault diagnosis and feature extraction. © 2015 Long Han et al."
"7004508767;55667257200;56521864800;57207272161;10240999000;","Numerical investigation of the coagulation mixing between dust and hygroscopic aerosol particles and its impacts",2015,"10.1002/2014JD022899","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84930379712&doi=10.1002%2f2014JD022899&partnerID=40&md5=b5d6bd0968cdb908dc831a14a322cb41","A statistical-numerical aerosol parameterization was incorporated into the Community Multiscale Air Quality modeling system to study the coagulation mixing process focusing on a dust storm event that occurred over East Asia. Simulation results show that the coagulation mixing process tends to decrease aerosol mass, surface area, and number concentrations over the dust source areas. Over the downwind oceanic areas, aerosol concentrations generally increased due to enhanced sedimentation as particles became larger upon coagulation. Themixture process can reduce the overall single-scattering albedo by up to 10% as a result of enhanced core with shell absorption by dust and reduction in the number of scattering particles. The enhanced dry deposition speed also altered the vertical distribution. In addition, the ability of aerosol particles to serve as cloud condensation nuclei (CCN) increased from around 107m-3 to above 109m-3 over downwind areas because a large amount of mineral dust particles became effective CCN with solute coating, except over the highly polluted areas where multiple collections of hygroscopic particles by dust in effect reduced CCN number. This CCN effect is much stronger for coagulation mixing than by the uptake of sulfuric acid gas on dust, although the nitric acid gas uptake was not investigated. The ability of dust particles to serve as ice nuclei may decrease or increase at low or high subzero temperatures, respectively, due to the switching from deposition nucleation to immersion freezing or haze freezing. © 2015. American Geophysical Union. All Rights Reserved."
"15755362800;7404330190;","A cloud-resolving simulation study on the merging processes and effects of topography and environmental winds",2012,"10.1175/JAS-D-11-049.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84861472503&doi=10.1175%2fJAS-D-11-049.1&partnerID=40&md5=7c70b7b47420e76fffe73f655afffcbb","The cloud-resolving fifth-generation Pennsylvania State University-National Center for Atmospheric Research MesoscaleModel (MM5) was used to study the cloud interactions and merging processes in the real case that generated a mesoscale convective system (MCS) on 23 August 2001 in the Beijing region. The merging processes can be grouped into three classes for the studied case: isolated nonprecipitating and precipitating cell merging, cloud cluster merging, and echo core or updraft core merging within cloud systems. The mechanisms responsible for the multiscale merging processes were investigated. The merging process between nonprecipitating cells and precipitating cells and that between clusters is initiated by forming an upperlevel cloud bridge between two adjacent clouds due to upper-level radial outflows in one vigorous cloud. The cloud bridge is further enhanced by a favorable middle- and upper-level pressure gradient force directed from one cloud to its adjacent cloud by accelerating cloud particles being horizontally transported from the cloud to its adjacent cloud and induce the redistribution of condensational heating, which destabilizes the air at and below the cloud bridge and forms a favorable low-level pressure structure for low-level water vapor convergence and merging process. The merging of echo cores within the mesoscale cloud happens because of the interactions between low-level cold outflows associated with the downdrafts formed by these cores. Further sensitivity studies on the effects of topography and large-scale environmental winds suggest that the favorable pressure gradient force from one cloud to its adjacent cloud and stronger low-level water vapor convergence produced by the topographic lifting of large-scale low-level airflow determine further cloud merging processes over the mountain region. © 2012 American Meteorological Society."
"7101959253;7005626683;","A cloud-resolving model with an adaptive vertical grid for boundary layer clouds",2011,"10.1175/2010JAS3638.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79958695275&doi=10.1175%2f2010JAS3638.1&partnerID=40&md5=21a68e135f98e482baaa518690aa3730","Accurate cloud-resolving model simulations of cloud cover and cloud water content for boundary layer clouds are difficult to achieve without vertical grid spacing well below 100 m, especially for inversion-topped stratocumulus. The need for fine vertical grid spacing presents a significant impediment to global or large regional simulations using cloud-resolving models, including the Multiscale Modeling Framework (MMF), in which a two-dimensional or small three-dimensional cloud-resolving model is embedded into each grid cell of a global climate model in place of more traditional cloud parameterizations. One potential solution to this problem is to use a model with an adaptive vertical grid (i.e., a model that is able to add vertical layers where and when needed) rather than trying to use a fixed grid with fine vertical spacing throughout the boundary layer. This article examines simulations with an adaptive vertical grid for three well-studied stratocumulus cases based on observations from the second Dynamics and Chemistry of Marine Stratocumulus (DYCOMS-II) experiment, the Atlantic Stratocumulus Transition Experiment (ASTEX), and the Atlantic Trade Cumulus Experiment (ATEX). For each case, three criteria are examined for determining where to add or remove vertical layers. One criterion is based on the domain-averaged potential temperature profile; the other two are based on the ratio of the estimated subgrid-scale to total water flux and turbulent kinetic energy. The results of the adaptive vertical grid simulations are encouraging in that these simulations are able to produce results similar to simulations using fine vertical grid spacing throughout the boundary layer, while using many fewer vertical layers. © 2011 American Meteorological Society."
"9272499100;7004372407;15823290900;6701750112;55398698300;","Influence of gravity waves on fog structure revealed by a millimeter-wave scanning Doppler radar",2007,"10.1029/2005JD006648","https://www.scopus.com/inward/record.uri?eid=2-s2.0-34250320138&doi=10.1029%2f2005JD006648&partnerID=40&md5=876741abe9ac6948d29053740aaa2c45","Multiscale band structure in fog influenced by gravity waves and Kelvin-Helmholtz instability (KHI) is studied based on observations with a millimeter-wave scanning Doppler radar on August 2000 in Kushiro District, Hokkaido Prefecture, Japan. Band structure in fog having radar reflectivity >-20 dBZ and a scale of ∼1.5 km was observed around 50 m altitude. The band structure was also observed in Doppler velocity. The band structure in both radar reflectivity and Doppler velocity propagated northwestward with a speed of 4.17 m s-1. From linear gravity wave theory it is estimated that the observed gravity waves had a horizontal wavelength of 1.5 km and period of 6 min. The updraft induced by gravity waves is estimated to be 7.8 cm s-1. The increase in liquid water content (LWC) caused by the updraft is 0.035 g m-1, and the increase of radar reflectivity is 2 dBZ. Within the band structure induced by the gravity waves (horizontal scale ∼1.5 km), roll structure with a smaller horizontal scale (∼300-600 m) was also observed in radar reflectivity. A previous study has shown that this smaller-scale roll structure is caused by shear-induced KHI. This study shows that both gravity waves and KHI modulated the structure of fog and resulted in the existence of multiscale (1.5 km and 300-600 m scale) fog structure. Copyright 2007 by the American Geophysical Union."
"12143775300;6603627233;7403572534;","Periodic evolution of multiscale precipitation systems developed within a Baiu frontal cloud cluster",2006,"10.2151/jmsj.84.497","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33748054284&doi=10.2151%2fjmsj.84.497&partnerID=40&md5=7df2eeddf570be4cc240cac67703d547","A meso-α-scale cloud cluster (CC) was observed in the Baiu frontal zone, located southwest of Kyushu, Japan, on July 7, 1996. It was characterized by a lifespan of approximately 20 hours, stationary motion, and heavy precipitation of over 200 mm in a period of 12 hours. This paper contains a report of the characteristic features of internal multiscale precipitation systems observed within the CC, and their periodic evolutions as newly found facts. The CC consisted of a convective rainfall region, characterized by a meso-βL-scale (100-200 km) lineshaped convective system (convective line, MβLCL), and a weak stratiform rainfall region on the lee side of the MβLCL. The MβLCL consisted of several band-shaped meso-βS-scale (20-100 km) convective systems (MβSCSs), and each MβSCS consisted of meso-γ-scale cumulonimbus clouds. The environmental atmosphere was characterized by a warm and moist inflow in the shallow layer (below 500 m in height) associated with a cyclonic circulation of slow moving and shallow depression. Additionally, the CC was located within a large temperature gradient zone in the lower atmosphere (below 4000 m in height) along the Baiu front. These were favorable environments for the generation and maintenance of the MβLCL. The MβLCLs were periodically generated with an interval of 5-6 hours in almost the same region, and they showed a common evolution of structure and processes. The behavior of cold pools formed by the MβLCLs on the northern side of the MβLCL played a key role in the periodic evolution. The developed cold pool intensified the MβCSs in the MβLCL and modified one of the MβsCSs into an arc-shaped MβsCS, that had similar characteristics to those of squall lines. Simultaneously, the arc-shaped MβsCS became the sole MβsCS that constituted MβLCL. Finally, the MβLCL decayed with the expansion of the cold pool. Another MβLCL was generated when the favorable environment was restored after the cold pool dissipated, and the evolution process of the MβLCL was repeated. © 2006, Meteorological Society of Japan."
"27868095600;7202929125;16070455300;7006767461;23485063600;7102460519;9841991200;43361931100;","Gravity, Magnetic Field, and Turbulence: Relative Importance and Impact on Fragmentation in the Infrared Dark Cloud G34.43+00.24",2019,"10.3847/1538-4357/ab1484","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85069452889&doi=10.3847%2f1538-4357%2fab1484&partnerID=40&md5=19b6b4c81aab571af26e3d5443ebb229","We investigate the interplay between magnetic (B) field, gravity, and turbulence in the fragmentation process of cores within the filamentary infrared dark cloud G34.43+00.24. We observe the magnetic field morphology across G34.43, traced with thermal dust polarization at 350 μm with an angular resolution of 10″ (0.18 pc), and compare with the kinematics obtained from N2H+ across the filament. We derive local velocity gradients from N2H+, tracing motion in the plane of sky, and compare with the observed local B field orientations in the plane of sky. The B field orientations are found to be perpendicular to the long axis of the filament toward the MM1 and MM2 ridge, suggesting that the B field can guide material toward the filament. Toward MM3, the B field orientations appear more parallel to the filament and aligned with the elongated core of MM3, indicating a different role of the B field. In addition to a large-scale east-west velocity gradient, we find a close alignment between local B field orientations and local velocity gradients toward the MM1/MM2 ridge. This local correlation in alignment suggests that gas motions are influenced by the B field morphology or vice versa. Additionally, this alignment seems to become even closer with increasing integrated emission in N2H+, possibly indicating that a growing gravitational pull alignes the B field and gas motion more and more. We analyze and quantify B field, gravity, turbulence, and their relative importance toward the MM1, MM2, and MM3 regions with various techniques over two scales, a larger clump area at 2 pc scale and the smaller core area at 0.6 pc scale. While gravitational energy, B field, and turbulent pressure all grow systematically from large to small scale, the ratios among the three constituents clearly develop differently over scale. We propose that this varying relative importance between B field, gravity, and turbulence over scale drives and explains the different fragmentation types seen at subparsec scale (no fragmentation in MM1; aligned fragmentation in MM2; clustered fragmentation in MM3). We discuss uncertainties, subtleties, and the robustness of our conclusion, and we stress that a multiscale joint analysis is required to understand the dynamics in these systems. © 2019. The American Astronomical Society."
"36538539800;53881502900;56942554300;6603051005;56401135900;22036956700;14009037000;6602675912;","Multiscale applications of two online-coupled meteorology-chemistry models during recent field campaigns in Australia, Part I: Model description and WRF/Chem-ROMS evaluation using surface and satellite data and sensitivity to spatial grid resolutions",2019,"10.3390/atmos10040189","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85064085281&doi=10.3390%2fatmos10040189&partnerID=40&md5=75dc5ac6b7c8cd92c77b3e0692e15fdc","Air pollution and associated human exposure are important research areas in Greater Sydney, Australia. Several field campaigns were conducted to characterize the pollution sources and their impacts on ambient air quality including the Sydney Particle Study Stages 1 and 2 (SPS1 and SPS2), and the Measurements of Urban, Marine, and Biogenic Air (MUMBA). In this work, the Weather Research and Forecasting model with chemistry (WRF/Chem) and the coupled WRF/Chem with the Regional Ocean Model System (ROMS) (WRF/Chem-ROMS) are applied during these field campaigns to assess the models' capability in reproducing atmospheric observations. The model simulations are performed over quadruple-nested domains at grid resolutions of 81-, 27-, 9-, and 3-km over Australia, an area in southeastern Australia, an area in New South Wales, and the Greater Sydney area, respectively. A comprehensive model evaluation is conducted using surface observations from these field campaigns, satellite retrievals, and other data. This paper evaluates the performance of WRF/Chem-ROMS and its sensitivity to spatial grid resolutions. The model generally performs well at 3-, 9-, and 27-km resolutions for sea-surface temperature and boundary layer meteorology in terms of performance statistics, seasonality, and daily variation. Moderate biases occur for temperature at 2-m and wind speed at 10-m in the mornings and evenings due to the inaccurate representation of the nocturnal boundary layer and surface heat fluxes. Larger underpredictions occur for total precipitation due to the limitations of the cloud microphysics scheme or cumulus parameterization. The model performs well at 3-, 9-, and 27-km resolutions for surface O3 in terms of statistics, spatial distributions, and diurnal and daily variations. The model underpredicts PM2.5 and PM10 during SPS1 and MUMBA but overpredicts PM2.5 and underpredicts PM10 during SPS2. These biases are attributed to inaccurate meteorology, precursor emissions, insufficient SO2 conversion to sulfate, inadequate dispersion at finer grid resolutions, and underprediction in secondary organic aerosol. The model gives moderate biases for net shortwave radiation and cloud condensation nuclei but large biases for other radiative and cloud variables. The performance of aerosol optical depth and latent/sensible heat flux varies for different simulation periods. Among all variables evaluated, wind speed at 10-m, precipitation, surface concentrations of CO, NO, NO2, SO2, O3, PM2.5, and PM10, aerosol optical depth, cloud optical thickness, cloud condensation nuclei, and column NO2 show moderate-to-strong sensitivity to spatial grid resolutions. The use of finer grid resolutions (3- or 9-km) can generally improve the performance for those variables. While the performance for most of these variables is consistent with that over the U.S. and East Asia, several differences along with future work are identified to pinpoint reasons for such differences. © 2019 by the authors."
"36538539800;56942554300;53881502900;6603051005;56401135900;22036956700;14009037000;6602675912;","Multiscale applications of two online-coupled meteorology-chemistry models during recent field campaigns in Australia, Part II: Comparison of WRF/Chem and WRF/Chem-ROMS and impacts of air-sea interactions and boundary conditions",2019,"10.3390/ATMOS10040210","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85068913452&doi=10.3390%2fATMOS10040210&partnerID=40&md5=129a43be6504b9ff9f06b68c6c2d0749","Air-sea interactions play an important role in atmospheric circulation and boundary layer conditions through changing convection processes and surface heat fluxes, particularly in coastal areas. These changes can affect the concentrations, distributions, and lifetimes of atmospheric pollutants. In this Part II paper, the performance of theWeather Research and Forecasting model with chemistry (WRF/Chem) and the coupled WRF/Chem with the Regional Ocean Model System (ROMS) (WRF/Chem-ROMS) are intercompared for their applications over quadruple-nested domains in Australia during the three following field campaigns: The Sydney Particle Study Stages 1 and 2 (SPS1 and SPS2) and the Measurements of Urban, Marine, and Biogenic Air (MUMBA). The results are used to evaluate the impact of air-sea interaction representation in WRF/Chem-ROMS on model predictions. At 3, 9, and 27 km resolutions, compared to WRF/Chem, the explicit air-sea interactions in WRF/Chem-ROMS lead to substantial improvements in simulated sea-surface temperature (SST), latent heat fluxes (LHF), and sensible heat fluxes (SHF) over the ocean, in terms of statistics and spatial distributions, during all three field campaigns. The use of finer grid resolutions (3 or 9 km) effectively reduces the biases in these variables during SPS1 and SPS2 by WRF/Chem-ROMS, whereas it further increases these biases for WRF/Chem during all field campaigns. The large differences in SST, LHF, and SHF between the two models lead to different radiative, cloud, meteorological, and chemical predictions. WRF/Chem-ROMS generally performs better in terms of statistics and temporal variations for temperature and relative humidity at 2 m, wind speed and direction at 10 m, and precipitation. The percentage differences in simulated surface concentrations between the two models are mostly in the range of ±10% for CO, OH, and O3, ±25% for HCHO, ±30% for NO2, ±35% for H2O2, ±50% for SO2, ±60% for isoprene and terpenes, ±15% for PM2.5, and ±12% for PM10. WRF/Chem-ROMS at 3 km resolution slightly improves the statistical performance of many surface and column concentrations. WRF/Chem simulations with satellite-constrained boundary conditions (BCONs) improve the spatial distributions and magnitudes of column CO for all field campaigns and slightly improve those of the column NO2 for SPS1 and SPS2, column HCHO for SPS1 and MUMBA, and column Oc for SPS2 at 3 km over the Greater Sydney area. The satellite-constrained chemical BCONs reduce the model biases of surface CO, NO, and O3 predictions at 3 km for all fieldcampaigns, surface PM2.5 predictions at 3 km for SPS1 and MUMBA, and surface PM10 predictions at all grid resolutions for all field campaigns. A more important role of chemical BCONs in the Southern Hemisphere, compared to that in the Northern Hemisphere reported in this work, indicates a crucial need in developing more realistic chemical BCONs for O3 in the relatively clean SH. © 2019 by the authors."
"57193752928;7501466543;12786487900;55205881600;57190226620;11540162300;25422350800;56421713400;6602623668;","Comparison of Dust Impact and Solitary Wave Signatures Detected by Multiple Electric Field Antennas Onboard the MMS Spacecraft",2018,"10.1029/2018JA025380","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85052462999&doi=10.1029%2f2018JA025380&partnerID=40&md5=9b45a74b203efda1a3f08cd9d489d2f6","Dust impact detection by electric field instruments is a relatively new method. However, the influence of dust impacts on electric field measurements is not completely understood and explained. A better understanding is very important for reliable dust impact identification, especially in environments with low dust impact rate. Using data from Earth-orbiting Magnetospheric Multiscale mission (MMS) spacecraft, we present a study of various pulses detected simultaneously by multiple electric field antennas in the monopole (probe-to-spacecraft potential measurement) and dipole (probe-to-probe potential measurement) configurations. The study includes data obtained during an impact of a millimeter-sized object. We show that the identification of dust impacts by a single antenna is a very challenging issue in environments where solitary waves are commonly present and that some pulses can be easily misinterpreted as dust impacts. We used data from multiple antennas to distinguish between changes in the spacecraft potential (dust impact) and structures in the ambient plasma or electric field. Our results indicate that an impact cloud is in some cases able to influence the potential of the electric field antenna during its expansion. ©2018. American Geophysical Union. All Rights Reserved."
"54421583300;7404970050;","Potentials in improving predictability of multiscale tropical weather systems evaluated through ensemble assimilation of simulated satellite-based observations",2018,"10.1175/JAS-D-17-0245.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047214447&doi=10.1175%2fJAS-D-17-0245.1&partnerID=40&md5=4a305545fdd9fa5e43e3a59ffbcf1313","As a follow-up of our recent paper on the practical and intrinsic predictability of multiscale tropical weather and equatorial waves, this study explores the potentials in improving the analysis and prediction of these weather systems through assimilating simulated satellite-based observations with a regional ensemble Kalman filter (EnKF). The observing networks investigated include the retrieved temperature and humidity profiles from the Advanced TIROS Operational Vertical Sounder (ATOVS) and global positioning system radio occultation (GPSRO), the atmospheric motion vectors (AMVs), infrared brightness temperature from Meteosat-7 (Met7-Tb), and retrieved surface wind speed from the Cyclone Global Navigation Satellite System (CYGNSS). It is found that assimilating simulated ATOVS thermodynamic profiles and AMV winds improves the accuracy of wind, temperature, humidity, and hydrometeors for scales larger than 200 km. The skillful forecast lead times can be extended by as much as 4 days for scales larger than 1000 km. Assimilation of Met7-Tb further improves the analysis of cloud hydrometeors even at scales smaller than 200 km. Assimilating CYGNSS surface winds further improves the low-level wind and temperature. Meanwhile, the impact from assimilating the current-generation GPSRO data with better vertical resolution and accuracy is comparable to assimilating half of the current ATOVS profiles, while a hypothetical 25-times increase in the number of GPSRO profiles can potentially exceed the impact from assimilating the current network of retrievedATOVSprofiles. Our study not only shows great promises in further improving practical predictability of multiscale equatorial systems but also provides guidance in the evaluation and design of current and future spaceborne observations for tropical weather. © 2018 American Meteorological Society."
"6507973681;57200115162;6602505244;6602489251;57188719166;","Use of DEMs derived from TLS and HRSI data for landslide feature recognition",2018,"10.3390/ijgi7040160","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85046539329&doi=10.3390%2fijgi7040160&partnerID=40&md5=f6f69ab827baa189377ef71d61e4034d","This paper addresses the problems arising from the use of data acquired with two different remote sensing techniques—high-resolution satellite imagery (HRSI) and terrestrial laser scanning (TLS)—for the extraction of digital elevation models (DEMs) used in the geomorphological analysis and recognition of landslides, taking into account the uncertainties associated with DEM production. In order to obtain a georeferenced and edited point cloud, the two data sets require quite different processes, which are more complex for satellite images than for TLS data. The differences between the two processes are highlighted. The point clouds are interpolated on a DEM with a 1 m grid size using kriging. Starting from these DEMs, a number of contour, slope, and aspect maps are extracted, together with their associated uncertainty maps. Comparative analysis of selected landslide features drawn from the two data sources allows recognition and classification of hierarchical and multiscale landslide components. Taking into account the uncertainty related to the map enables areas to be located for which one data source was able to give more reliable results than another. Our case study is located in Southern Italy, in an area known for active landslides. © 2018 by the authors."
"57191996036;36815993100;55452292200;35313639700;57213429877;56978385600;57196117536;7402400723;8437626600;","Aerosol optical properties over China from RAMS-CMAQ Model compared with CALIOP observations",2017,"10.3390/atmos8100201","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85031894116&doi=10.3390%2fatmos8100201&partnerID=40&md5=db371ffdf17e22553c451cdd1c38068a","The horizontal and vertical distributions of aerosol optical properties over China in 2013-2015 were investigated using RAMS (Regional Atmospheric Modeling System)-CMAQ (Models-3 Community Multiscale Air Quality) simulations and CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) observations. To better understand the performance of the RAMS-CMAQ model over China, comparisons with the ground-based Sun photometers AERONET (Aerosol Robotic Network), MODIS (Moderate Resolution Imaging Spectroradiometers) data and the on-board Lidar CALIOP were used for comprehensive evaluations, which could characterize the abilities of the model to simulate the spatial and vertical distributions of the AOD (Aerosol Optical Depth) as well as the optical properties for four seasons. Several high value areas (e.g., the Sichuan Basin, Taklamakan Desert, North China Plain, and Yangtze River Delta) were found over China during the study period, with the maximum mean AOD (CALIOP: ~0.7; RAMS-CMAQ: >1) in the Sichuan district. Compared with AODs of AERONET, both the CALIOP and RAMS-CMAQ AODs were underestimated, but the RAMS-CMAQ data show a better correlation with AERONET (AERONET vs. RAMS-CMAQ R: 0.69, AERONET vs. CALIOP R: 0.5). The correlation coefficients between RAMS-CMAQ and CALIOP are approximately 0.6 for all four seasons. The AEC (Aerosol Extinction Coefficient) vertical profiles over major cities and their cross sections exhibit two typical features: (1) most of the AEC peaks occurred in the lowest ~0.5 km, decreasing with increasing altitude; and (2) the RAMS-CMAQ AEC underestimated the region with high AODs in the northwest of China and overestimated the region with high AODs in the east-central plain and the central basin regions. The major difference in the AEC values of RAMS-CMAQ and CALIOP is mainly caused by the level of relative humidity and the hygroscopic growth effects of water-soluble aerosols, especially, in the Sichuan district. In general, both the column and vertical RAMS-CMAQ aerosol optical properties could be supplemented efficiently when satellite observations are not available or invalid over China in the applications of climate change and air pollution. © 2017 by the authors."
"56768490800;7203054240;7102079208;7003666669;56162305900;7202048112;7202155374;35609878300;","Influence of Superparameterization and a Higher-Order Turbulence Closure on Rainfall Bias Over Amazonia in Community Atmosphere Model Version 5",2017,"10.1002/2017JD026576","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85030232005&doi=10.1002%2f2017JD026576&partnerID=40&md5=ba498a9a5c83b541321e3be468755733","We evaluate the Community Atmosphere Model Version 5 (CAM5) with a higher-order turbulence closure scheme, named Cloud Layers Unified By Binomials (CLUBB), and a Multiscale Modeling Framework, referred to as the “superparameterization” (SP) with two different microphysics configurations to investigate their influences on rainfall simulations over southern Amazonia. The two different microphysics configurations in SP are the one-moment cloud microphysics without aerosol treatment (SP1) and two-moment cloud microphysics coupled with aerosol treatment (SP2). Results show that both SP2 and CLUBB effectively reduce the low biases of rainfall, mainly during the wet season, and reduce low biases of humidity in the lower troposphere with further reduced shallow clouds and increased surface solar flux. These changes increase moist static energy in the lower atmosphere and contribute to stronger convection and more rainfall. SP2 appears to realistically capture the observed increase of relative humidity prior to deep convection, and it significantly increases rainfall in the afternoon; CLUBB significantly delays the afternoon peak rainfall and produces more precipitation in the early morning, due to more gradual transition between shallow and deep convection. In CAM5 and CAM5 with CLUBB, occurrence of more deep convection appears to be a result of stronger heating rather than higher relative humidity. ©2017. American Geophysical Union. All Rights Reserved."
"56434851400;7004978125;","Upscale impact of mesoscale disturbances of tropical convection on synoptic-scale equatorial waves in two-dimensional flows",2017,"10.1175/JAS-D-17-0068.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029056130&doi=10.1175%2fJAS-D-17-0068.1&partnerID=40&md5=23a56ea97b91538206f21fb8bb6bb85b","Superclusters on the synoptic scale containing mesoscale systems are frequently organized by convectively coupled equatorial waves (CCEWs). Present-day global models struggle to simulate multiscale tropical convection, and the upscale effects of mesoscale systems are not well understood. A simple two-dimensional multiscale model with prescribed two-scale heating and eddy transfer of momentum and temperature drives the synoptic-scale circulation, successfully reproduces key features of flow fields with a front-to-rear tilt, and compares well with results from a cloud-resolving model (CRM). In the scenario with an elevated upright mean heating, the tilted vertical structure of synoptic-scale circulation is still induced by the upscale impact of mesoscale disturbances. In a faster propagation scenario, the upscale impact becomes less important as a result of competing effects of eddy transfer of momentum and temperature, while the synoptic-scale circulation response to mean heating dominates, in agreement with cloud-resolving models. In the unrealistic scenario with upward-westward-tilted mesoscale heating, positive potential temperature anomalies are induced in the leading edge, which will suppress shallow convection in a moist environment. © 2017 American Meteorological Society."
"57192115362;22634069200;56366080900;56495534400;22634073600;56693931600;","Ocean Front Detection from Instant Remote Sensing SST Images",2016,"10.1109/LGRS.2016.2618941","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84997724731&doi=10.1109%2fLGRS.2016.2618941&partnerID=40&md5=4cac6afb0ada8da14ecbb11f68bae3af","Identifying fronts manually from satellite images is a tedious and subjective task. Accordingly, edge detection algorithms are introduced for automatic detection of fronts. However, traditional algorithms cannot be applied to cloud-contaminated images, because missing data caused by occasional cloud coverage interferes with front detection. To diminish this risk, this letter proposes a new algorithm for a quick and an accurate detection of fronts from an instant cloud-contaminated sea surface temperature (SST) image, instead of depending on the daily or weekly averaged SST images. This algorithm adopts a data-driven analog interpolation method, which estimates missing values from the historical data of the same region. After reducing the contour between the interpolated data and the original data, an instant front detection algorithm is proposed based on microcanonical multiscale formalism (MMF). The algorithm utilizes MMF to detect singularity exponents (SEs), and then enhances the features detected in a cloud-contaminated region. Finally, a threshold is set to extract fronts from SE. Experimental results on an AVHRR satellite SST image of 12:00 o'clock covering China Coastal waters confirmed the effectiveness of the proposed algorithm. © 2004-2012 IEEE."
"6508001480;6507815737;57203254582;","Modelling the structure of molecular clouds - I. A multiscale energy equipartition",2016,"10.1093/mnras/stw781","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84975061833&doi=10.1093%2fmnras%2fstw781&partnerID=40&md5=7274036d8825ba1d1673cb9b8e92ba2a","We present a model for describing the general structure of molecular clouds (MCs) at early evolutionary stages in terms of their mass-size relationship. Sizes are defined through threshold levels at which equipartitions between gravitational, turbulent and thermal energy |W| ~ f(Ekin + Eth) take place, adopting interdependent scaling relations of velocity dispersion and density and assuming a lognormal density distribution at each scale. Variations of the equipartition coefficient 1 ≤ f ≤ 4 allow for modelling of star-forming regions at scales within the size range of typical MCs (≳4 pc). Best fits are obtained for regions with low or no star formation (Pipe, Polaris) as well for such with star-forming activity but with nearly lognormal distribution of column density (Rosette). An additional numerical test of the model suggests its applicability to cloud evolutionary times prior to the formation of first stars. © 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society."
"54585176800;7004978125;7801642934;","Cloud-radiation feedback and atmosphere-ocean coupling in a stochastic multicloud model",2015,"10.1016/j.dynatmoce.2015.05.003","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84931263082&doi=10.1016%2fj.dynatmoce.2015.05.003&partnerID=40&md5=07302337a5612e5f223ca1182b04767c","Despite recent advances in supercomputing, current general circulation models (GCMs) have significant problems in representing the variability associated with organized tropical convection. Furthermore, due to high sensitivity of the simulations to the cloud radiation feedback, the tropical convection remains a major source of uncertainty in long-term weather and climate forecasts. In a series of recent studies, it has been shown, in paradigm two-baroclinic-mode systems and in aquaplanet GCMs, that a stochastic multicloud convective parameterization based on three cloud types (congestus, deep and stratiform) can be used to improve the variability and the dynamical structure of tropical convection, including intermittent coherent structures such as synoptic and mesoscale convective systems. Here, the stochastic multicloud model is modified with a parameterized cloud radiation feedback mechanism and atmosphere-ocean coupling. The radiative convective feedback mechanism is shown to increase the mean and variability of the Walker circulation. The corresponding intensification of the circulation is associated with propagating synoptic scale systems originating inside of the enhanced sea surface temperature area. In column simulations, the atmosphere ocean coupling introduces pronounced low frequency convective features on the time scale associated with the depth of the mixed ocean layer. However, in the presence of the gravity wave mixing of spatially extended simulations, these features are not as prominent. This highlights the deficiency of the column model approach at predicting the behavior of multiscale spatially extended systems. Overall, the study develops a systematic framework for incorporating parameterized radiative cloud feedback and ocean coupling which may be used to improve representation of intraseasonal and seasonal variability in GCMs. © 2015 Elsevier B.V."
"7004978125;6507400558;54585176800;","Effects of rotation and mid-troposphere moisture on organized convection and convectively coupled gravity waves",2014,"10.1007/s00382-014-2222-5","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84939890232&doi=10.1007%2fs00382-014-2222-5&partnerID=40&md5=f3f7446413bba9c929beb08c67a361e6","Atmospheric convection has the striking capability to organize itself into a hierarchy of cloud clusters and super-clusters on scales ranging from the convective cell of a few kilometres to planetary scale disturbances such as the Madden–Julian oscillation. It is widely accepted that this phenomenon is due in large part to the two-way coupling between convective processes and equatorially trapped waves and planetary scale flows in general. However, the physical mechanisms responsible for this multiscale organization and the associated across-scale interactions are poorly understood. The two main peculiarities of the tropics are the vanishing of the Coriolis force at the equator and the abundance of mid-level moisture. Here we test the effect of these two physical properties on the organization of convection and its interaction with gravity waves in a simplified primitive equation model for flows parallel to the equator. Convection is represented by deterministic as well as stochastic multicloud models that are known to represent organized convection and convectively coupled waves quite well. It is found here that both planetary rotation and mid-troposphere moisture are important players in the diminishing of organized convection and convectively coupled gravity wave activity in the subtropics and mid-latitudes. The meridional mean circulation increases with latitude while the mean zonal circulation is much shallower and is dominated by mid-level jets, reminiscent of a second baroclinic mode circulation associated with a congestus mode instability in the model. This is consistent with the observed shallow Hadley and Walker circulations accompanied by congestus cloud decks in the higher latitude tropics and sub-tropics. Moreover, deep convection activity in the stochastic model simulations becomes very patchy and unorganized as the computational domain is pushed towards the subtropics and mid-latitudes. This is consistent with previous work based on cloud resolving modeling simulations on smaller domains. © 2014, Springer-Verlag Berlin Heidelberg."
"7201784177;7101661890;","Toward an understanding of vertical momentum transports in cloud-system-resolving model simulations of multiscale tropical convection",2013,"10.1175/JAS-D-13-068.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84885943760&doi=10.1175%2fJAS-D-13-068.1&partnerID=40&md5=ff818a7a404b22dd884777a7961b471f","This study examines the characteristics of convective momentum transport (CMT) and gravity wave momentum transport (GWMT) in two-dimensional cloud-system-resolving model simulations, including the relationships between the two transports. A linear group velocity criterion is shown to objectively separate CMT and GWMT. TheGWMTcontribution is mostly consistent with upward-propagating gravity waves and is present in the troposphere and the stratosphere. The CMT contribution forms a large part of the residual (nonupward-propagating contribution) and dominates the fluxes in the troposphere. Additional analysis of the vertical sensible heat flux supports the physical interpretation of the two contributions, further isolating the effects of unstable convection from vertically propagating gravity waves. The role of transient and nonconservative (friction and diabatic heating) processes in generating momentum flux and their dependence on changes in convective organization was assessed using a pseudomomentum budget analysis. Nonconservative effects were found to dominate the transports; the GWMT contribution involved a diabatic source region in the troposphere and a dissipative sink region in the stratosphere. The CMT contribution was consistent with transport between the boundary layer and free troposphere via tilted convection. Transient buoyancy-vorticity correlations highlighted wave sources in the region of convective outflow and the boundary layer. These sources were akin to the previously described ''mechanical oscillator'' mechanism. Fluxes associated with this upper-level source were most sensitive to convective organization, highlighting the mechanism by which changes in organization are communicated to GWMT. The results elucidate important interactions between CMT and GWMT, adding further weight to suggestions that the two transports should be linked in parameterizations. © 2013 American Meteorological Society."
"57194974100;11839267100;7005461477;7202772927;","Comparing the convective structure and microphysics in two sahelian mesoscale convective systems: Radar observations and crm simulations",2013,"10.1175/MWR-D-12-00053.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84874984905&doi=10.1175%2fMWR-D-12-00053.1&partnerID=40&md5=c9d6f9b58ed5ab1c1916f2a4735ea641","Two mesoscale convective systems (MCSs) observed during the African Monsoon Multidisciplinary Analyses(AMMA)experiment are simulated using the three-dimensional (3D) Goddard Cumulus Ensemble model. This study was undertaken to determine the performance of the cloud-resolving model in representing distinct convective and microphysical differences between the two MCSs over a tropical continental location. Simulations are performed using 1-km horizontal grid spacing, a lower limit on current embedded cloudresolving models within a global multiscale modeling framework. Simulated system convective structure and microphysics are compared to radar observations using contoured frequency-by-altitude diagrams (CFADs), calculated ice and water mass, and identified hydrometeor variables. Vertical distributions of ice hydrometeors indicate underestimation at the mid- and upper levels, partially due to the inability of the model to produce adequate system heights. The abundance of high-reflectivity values below and near the melting level in the simulation led to a broadening of the CFAD distributions. Observed vertical reflectivity profiles show that high reflectivity is present at greater heights than the simulations produced, thought to be a result of using a single-moment microphysics scheme. Relative trends in the population of simulated hydrometeors are in agreement with observations, though a secondary convective burst is not well represented. Despite these biases, the radar-observed differences between the two cases are noticeable in the simulations as well, suggesting that the model has some skill in capturing observed differences between the two MCSs. ©2013 American Meteorological Society."
"7801642934;7201504886;","Multiscale models for cumulus cloud dynamics",2010,"10.1175/2010JAS3380.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77958581865&doi=10.1175%2f2010JAS3380.1&partnerID=40&md5=46943662d6cf3d24aedabb15f59b0ac0","Cumulus clouds involve processes on a vast range of scales-including cloud droplets, turbulent mixing, and updrafts and downdrafts-and it is often difficult to determine how processes on different scales interact with each other. In this article, several multiscale asymptotic models are derived for cumulus cloud dynamics in order to (i) provide a systematic scale analysis on each scale and (ii) clarify the nature of interactions between different scales. In terms of scale analysis, it is shown that shallow cumulus updrafts can be described by balanced dynamics with a balance between source terms and ascent/descent; this is a cloud-scale version of socalled weak-temperature-gradient models. In terms of multiscale interactions, a model is derived that connects these balanced updrafts to the fluctuations within the balanced updraft envelope. These fluctuations describe parcels and updraft pulses, and this model encompasses some of the multiscale aspects of entrainment. In addition to this shallow cumulus model, to provide a broad picture of general cumulus dynamics, multiscale models are also derived for other scales; these include models for parcels and subparcel turbulent mixing and models for deep cumulus. Broadly speaking, the differences between the shallow and deep cases convey the notion that shallow cumulus dynamics are parcel dominated, whereas deep cumulus dynamics are updraft dominated; this is largely due to the difference in the apparent magnitude of the background temperature stratification. In addition to their use in guiding theory, the multiscale models also provide a framework for multiscale numerical simulations. © 2010 American Meteorological Society."
"57212495891;7101939964;","Diurnal variation of tropical convection during TOGA COARE IOP",2005,"10.1007/BF02918712","https://www.scopus.com/inward/record.uri?eid=2-s2.0-26644453572&doi=10.1007%2fBF02918712&partnerID=40&md5=391c9e87e48570b07c2370c628af88c9","Diurnal variation of tropical convection and kinematic and thermodynamic conditions was investigated for different large-scale environments of the convectively active and inactive periods by using satellite observations and surface measurements during the Intensive Observation Period (IOP) of the Tropical Ocean Global Atmosphere/Coupled Ocean-Atmosphere Response Experiment (TOGA/COARE). During the convectively active period, the features of nocturnal convection appear in vertical profiles of convergence, vertical velocity, heat source, and moisture sink. The specific humidity increases remarkably in the middle troposphere at dawn. On the other hand, the altitude of maximum convergence and that of the upward motion is lower during the convectively inactive period. The specific humidity peaks in the lower troposphere in the daytime and decreases in the middle troposphere. Spectral analyses of the time series of the infrared (IR) brightness temperature (TBB) and amounts of rainfall suggest multiscale temporal variation with a prominent diurnal cycle over land and oceanic regions such as the Intensive Flux Array (IFA) and the South Pacific Convergence Zone (SPCZ). Over land, the daily maximum of deep convection associated with cloud top temperature less than 208 K appears at midnight due to the daytime radiative heating and the sea-land breeze. Over the ocean, convection usually tends to occur at dawn for the convectively active period while in the afternoon during the inactive period. Comparing the diurnal variation of convection with large-scale variables, the authors inferred that moisture in the middle troposphere contributes mostly to the development of nocturnal convection over the ocean during the convectively active period."
"55176818100;7004978125;56434851400;","The Multiscale Impacts of Organized Convection in Global 2-D Cloud-Resolving Models",2018,"10.1029/2018MS001335","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85052407037&doi=10.1029%2f2018MS001335&partnerID=40&md5=c0470fa6efa53581962a71d1b0e6ee66","This paper studies the mechanisms behind the multiscale organization of tropical moist convection using a trio of cloud-resolving atmospheric simulations performed in a periodic two-dimensional 32,000-km domain. A simulation with interactive surface fluxes and long-wave radiation over a constant sea surface temperature of 300.15 K produces a planetary-scale self-aggregated patch of convection after 80 days of simulation. Fixing the surface fluxes and radiative cooling at a constant value suppresses this planetary-scale organization. However, increasing the stability at the tropopause by adding stratospheric heating produces a simulation, which generates a planetary-scale wave after just 30 days. This planetary-scale wave modulates eastward propagating synoptic-scale waves, which in turn modulate westward propagating mesoscale convective system. Low-pass filters are used to diagnose the feedbacks, which produce large-scale variance of zonal velocity, buoyancy, and humidity. The planetary-scale buoyancy variance and zonal velocity variance are related to the available potential energy (APE) and kinetic energy (KE) budgets, respectively. In the simulation with stratospheric heating, planetary-scale KE is created by vertical fluxes of zonal momentum, converted to APE, and then dissipated by latent heating, mixing, and other buoyancy sources. Without stratospheric heating, the KE produced by these feedbacks is strongly damped in the stratosphere. The mesoscale eddy flux convergence of zonal momentum dominates the total vertical flux feedback on the planetary-scale KE, and its vertical structure is consistent with the westward propagating mesoscale convective systems. Overall, these results demonstrate that these eddy fluxes can organize two-dimensional deep convection on planetary scales in the absence of other diabatic feedbacks. ©2018. American Geophysical Union. All Rights Reserved."
"55338676800;7101959253;57206503877;","Sensitivities of Simulated Satellite Views of Clouds to Subgrid-Scale Overlap and Condensate Heterogeneity",2018,"10.1029/2017JD027680","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050503300&doi=10.1029%2f2017JD027680&partnerID=40&md5=57371580b63411a6f039db37c20c98e6","Satellite simulators are often used to account for limitations in satellite retrievals of cloud properties in comparisons between models and satellite observations. The purpose of this framework is to enable more robust evaluation of model cloud properties, so that differences between models and observations can more confidently be attributed to model errors. A critical step in this process is accounting for the difference between the spatial scales at which cloud properties are retrieved with those at which clouds are simulated in global models. In this study, we create a series of sensitivity tests using 4-km global model output from the multiscale modeling framework to evaluate the sensitivity of simulated satellite retrievals to common assumptions about cloud and precipitation overlap and condensate variability used in climate models whose grid spacing is many tens to hundreds of kilometers. We find the simulated retrievals are sensitive to these assumptions. Using maximum-random overlap with homogeneous cloud and precipitation condensate leads to errors in Multiangle Imaging Spectroradiometer and International Satellite Cloud Climatology Project-simulated cloud cover and in CloudSat-simulated radar reflectivity that are significant compared to typical differences between the model simulations and observations. A more realistic treatment of unresolved clouds and precipitation is shown to substantially reduce these errors. The sensitivity to these assumptions underscores the need for the adoption of more realistic subcolumn treatments in models and the need for consistency among subcolumn assumptions between models and simulators to ensure that simulator-diagnosed errors are consistent with the model formulation. ©2018. American Geophysical Union. All Rights Reserved."
"16317584800;57200599160;56458013900;","Contour extraction in buildings in airborne lidar point clouds using multiscale local geometric descriptors and visual analytics",2018,"10.1109/JSTARS.2018.2833801","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047836208&doi=10.1109%2fJSTARS.2018.2833801&partnerID=40&md5=b42cdee2e6f06663d2857d56af62071e","Topographic Light Detection and Ranging (LiDAR) captures geometric information of the topography of a geographical region, often using airborne platforms. The research and practice of analysis of point clouds acquired using LiDAR is more recent in comparison to that of LiDAR imagery. Point clouds are unstructured datasets, where its geometric or structural classification labels the constituent points as belonging to line-, surface-, or point-type features. We focus on line-type features in the LiDAR point clouds of urban residential areas, which enables extraction of building outlines. We use a multiscale local geometric descriptor (LGD), computed using tensor voting and gradient energy tensor to enhance specific line-type features, e.g., gable roofs. Given that LGDs are positive-semidefinite second-order tensors, we propose a tensor-based data analytic workflow for extraction of boundaries in building roofs using the LGD. We use the tensor representation of the LGD to extract 'tensorlines,' which are then postprocessed for extracting feature lines of the building roofs. Our proposed workflow provides the flexibility to the human-in-the-loop for exploration of point clouds for roof boundary tracing for selected buildings. We demonstrate the workflow for a two-plane gable roof. © 2008-2012 IEEE."
"57201111147;26655529300;35977156500;6603849280;","Deriving temporally continuous soil moisture estimations at fine resolution by downscaling remotely sensed product",2018,"10.1016/j.jag.2018.01.010","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85045972055&doi=10.1016%2fj.jag.2018.01.010&partnerID=40&md5=06700881e489f32a169ba48a863a8ebf","Land surface soil moisture (SSM) has important roles in the energy balance of the land surface and in the water cycle. Downscaling of coarse-resolution SSM remote sensing products is an efficient way for producing fine-resolution data. However, the downscaling methods used most widely require full-coverage visible/infrared satellite data as ancillary information. These methods are restricted to cloud-free days, making them unsuitable for continuous monitoring. The purpose of this study is to overcome this limitation to obtain temporally continuous fine-resolution SSM estimations. The local spatial heterogeneities of SSM and multiscale ancillary variables were considered in the downscaling process both to solve the problem of the strong variability of SSM and to benefit from the fusion of ancillary information. The generation of continuous downscaled remote sensing data was achieved via two principal steps. For cloud-free days, a stepwise hybrid geostatistical downscaling approach, based on geographically weighted area-to-area regression kriging (GWATARK), was employed by combining multiscale ancillary variables with passive microwave remote sensing data. Then, the GWATARK-estimated SSM and China Soil Moisture Dataset from Microwave Data Assimilation SSM data were combined to estimate fine-resolution data for cloudy days. The developed methodology was validated by application to the 25-km resolution daily AMSR-E SSM product to produce continuous SSM estimations at 1-km resolution over the Tibetan Plateau. In comparison with ground-based observations, the downscaled estimations showed correlation (R ≥ 0.7) for both ascending and descending overpasses. The analysis indicated the high potential of the proposed approach for producing a temporally continuous SSM product at fine spatial resolution. © 2018 Elsevier B.V."
"56031356000;7404493635;6602659336;56614955700;6603837066;55913351000;57203297366;7004554762;7005412075;15071316400;50961342600;14049230500;57203474131;24346627600;","The convection, aerosol, and synoptic-effects in the tropics (CAST) experiment: Building an understanding of multiscale impacts on caribbean weather via field campaigns",2017,"10.1175/BAMS-D-16-0192.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85028878503&doi=10.1175%2fBAMS-D-16-0192.1&partnerID=40&md5=216415e84f1cba8b96a02ca937c73a4b","The necessity to improve observational capabilities and to better understand local convective processes using western observations led to the Convection, Aerosol, and Synoptic-Effects in the Tropics (CAST) campaign. CAST was conducted by researchers from multiple institutions including the University. Three CAST phases were scheduled to monitor atmospheric conditions in western Puerto Rico during three of its distinct seasons including the midsummer drought, the dry season, and the early rainfall season. Supplemental CAST instrumentation included up to twice-daily radiosonde launches, three high-resolution radars, a ceilometer, a disdrometer, soil moisture sensors, and an aerosol speciation sampler, all on the western side of the island. The disdrometer, soil moisture sensors, and ceilometer ran continuously. To ensure optimal radiosonde launch times, NWS forecasts and weather maps, along with aerosol optical thickness (AOT) forecasts from the National Aeronautics and Space Administration (NASA) Goddard Earth Observing System (GEOS-5) model, were analyzed to ensure that a range of conditions including low and high AOT for dry and wet days were sampled. CAST also provides a basis for setting up modeling experiments centered around some of the more extreme convective events occurring during the experiment. The incorporation of a cloud-resolving model will allow us to further investigate multiscale interactions between large-and local-scale processes and zoom in on their effects on island convection and precipitation."
"55910516500;7005496535;","Probing the multiscale interplay between gravity and turbulence - power-law-like gravitational energy spectra of the Orion Complex",2017,"10.1093/mnras/stw2504","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85014805955&doi=10.1093%2fmnras%2fstw2504&partnerID=40&md5=2671d48895870d7a2a9e25306ce15d1c","Gravity plays a determining role in the evolution of the molecular ISM. In 2016, we proposed a measure called gravitational energy spectrum to quantify the importance of gravity on multiple physical scales. In this paper, using a wavelet-based decomposition technique, we derive the gravitational energy spectra of the Orion A and the Orion B molecular cloud from observational data. The gravitational energy spectra exhibit power-law-like behaviours. From a few parsec down to ~0.1 pc scale, the Orion A and Orion B molecular cloud have Ep(k) ~ k-1.88 and Ep(k) ~ k-2.09, respectively. These scaling exponents are close to the scaling exponents of the kinetic energy power spectrum of compressible turbulence (where E ~ k-2), with a near-equipartition of turbulent versus gravitational energy on multiple scales. This provides a clear evidence that gravity is able to counteract effectively against turbulent motion for these length-scales. The results confirm our earlier analytical estimates. For the Orion A molecular cloud, gravity inevitably dominates turbulence inside the cloud. Our results provide a clear observational proof that gravity is playing a determining role in the evolution these molecular clouds from the cloud scale down to ~0.1 pc. However, turbulence is likely to dominate in clouds such as California. The method is general and should be applicable to all the astrophysical problems where gravity plays a role. © 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society."
"36092736500;57217944117;6506778968;6602861236;16315109900;6602516573;57210237530;57188667427;7006512935;7102646025;","The parameterization of microchannel-plate-based detection systems",2016,"10.1002/2016JA022563","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84991508669&doi=10.1002%2f2016JA022563&partnerID=40&md5=776c1c8f10eb80987a4c605a4f0da6e4","The most common instrument for low-energy plasmas consists of a top-hat electrostatic analyzer (ESA) geometry coupled with a microchannel-plate-based (MCP-based) detection system. While the electrostatic optics for such sensors are readily simulated and parameterized during the laboratory calibration process, the detection system is often less well characterized. Here we develop a comprehensive mathematical description of particle detection systems. As a function of instrument azimuthal angle, we parameterize (1) particle scattering within the ESA and at the surface of the MCP, (2) the probability distribution of MCP gain for an incident particle, (3) electron charge cloud spreading between the MCP and anode board, and (4) capacitive coupling between adjacent discrete anodes. Using the Dual Electron Spectrometers on the Fast Plasma Investigation on NASA's Magnetospheric Multiscale mission as an example, we demonstrate a method for extracting these fundamental detection system parameters from laboratory calibration. We further show that parameters that will evolve in flight, namely, MCP gain, can be determined through application of this model to specifically tailored in-flight calibration activities. This methodology provides a robust characterization of sensor suite performance throughout mission lifetime. The model developed in this work is not only applicable to existing sensors but also can be used as an analytical design tool for future particle instrumentation. ©2016. American Geophysical Union. All Rights Reserved."
"57204954812;57196143493;57212075803;6506900202;7403931916;","Validation of a weather forecast model at radiance level against satellite observations allowing quantification of temperature, humidity, and cloud-related biases",2016,"10.1002/2016MS000751","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84988568690&doi=10.1002%2f2016MS000751&partnerID=40&md5=92a26e2c612f524a08bcb357981234b2","An established radiative transfer model (RTM) is adapted for simulating all-sky infrared radiance spectra from the Canadian Global Environmental Multiscale (GEM) model in order to validate its forecasts at the radiance level against Atmospheric InfraRed Sounder (AIRS) observations. Synthetic spectra are generated for 2 months from short-term (3–9 h) GEM forecasts. The RTM uses a monthly climatological land surface emissivity/reflectivity atlas. An updated ice particle optical property library was introduced for cloudy radiance calculations. Forward model brightness temperature (BT) biases are assessed to be of the order of ∼1 K for both clear-sky and overcast conditions. To quantify GEM forecast meteorological variables biases, spectral sensitivity kernels are generated and used to attribute radiance biases to surface and atmospheric temperatures, atmospheric humidity, and clouds biases. The kernel method, supplemented with retrieved profiles based on AIRS observations in collocation with a microwave sounder, achieves good closure in explaining clear-sky radiance biases, which are attributed mostly to surface temperature and upper tropospheric water vapor biases. Cloudy-sky radiance biases are dominated by cloud-induced radiance biases. Prominent GEM biases are identified as: (1) too low surface temperature over land, causing about −5 K bias in the atmospheric window region; (2) too high upper tropospheric water vapor, inducing about −3 K bias in the water vapor absorption band; (3) too few high clouds in the convective regions, generating about +10 K bias in window band and about +6 K bias in the water vapor band. © 2016. The Authors."
"36987319800;57203054708;","Simulation of subgrid orographic precipitation with an embedded 2-D cloud-resolving model",2016,"10.1002/2015MS000539","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84954305809&doi=10.1002%2f2015MS000539&partnerID=40&md5=33eb411fbe09a4ff590d1e7c03986abf","By explicitly resolving cloud-scale processes with embedded two-dimensional (2-D) cloud-resolving models (CRMs), superparameterized global atmospheric models have successfully simulated various atmospheric events over a wide range of time scales. Up to now, however, such models have not included the effects of topography on the CRM grid scale. We have used both 3-D and 2-D CRMs to simulate the effects of topography with prescribed ""large-scale"" winds. The 3-D CRM is used as a benchmark. The results show that the mean precipitation can be simulated reasonably well by using a 2-D representation of topography as long as the statistics of the topography such as the mean and standard deviation are closely represented. It is also shown that the use of a set of two perpendicular 2-D grids can significantly reduce the error due to a 2-D representation of topography. © 2015. The Authors."
"34876209700;24801829100;7401895830;36059595100;7405763496;","Weekly variability of precipitation induced by anthropogenic aerosols: A case study in Korea in summer 2004",2016,"10.1016/j.scitotenv.2015.10.020","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84945317956&doi=10.1016%2fj.scitotenv.2015.10.020&partnerID=40&md5=10d75a537d53b5c8864b208e24de7371","We examine the effect of anthropogenic aerosols on the weekly variability of precipitation in Korea in summer 2004 by using Weather Research and Forecasting (WRF) and Community Multiscale Air Quality (CMAQ) models. We conduct two WRF simulations including a baseline simulation with empirically based cloud condensation nuclei (CCN) number concentrations and a sensitivity simulation with our implementation to account for the effect of aerosols on CCN number concentrations. The first simulation underestimates observed precipitation amounts, particularly in northeastern coastal areas of Korea, whereas the latter shows higher precipitation amounts that are in better agreement with the observations. In addition, the sensitivity model with the aerosol effects reproduces the observed weekly variability, particularly for precipitation frequency with a high R at 0.85, showing 20% increase of precipitation events during the weekend than those during weekdays. We find that the aerosol effect results in higher CCN number concentrations during the weekdays and a three-fold increase of the cloud water mixing ratio through enhanced condensation. As a result, the amount of warm rain is generally suppressed because of the low auto-conversion process from cloud water to rain water under high aerosol conditions. The inefficient conversion, however, leads to higher vertical development of clouds in the mid-atmosphere with stronger updrafts in the sensitivity model, which increases by 21% cold-phase hydrometeors including ice, snow, and graupel relative to the baseline model and ultimately results in higher precipitation amounts in summer. © 2015 Elsevier B.V."
"37116849700;7409074131;56611366900;8859530100;55745955800;37018824600;6701333444;55272477500;","Development of fine-resolution analyses and expanded large-scale forcing properties: 2. Scale awareness and application to single-column model experiments",2015,"10.1002/2014JD022254","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84923207976&doi=10.1002%2f2014JD022254&partnerID=40&md5=3943c85c99a2c72fc5ad2371ce56eec2","Fine-resolution three-dimensional fields have been produced using the Community Gridpoint Statistical Interpolation (GSI) data assimilation system for the U.S. Department of Energy’s Atmospheric Radiation Measurement Program (ARM) Southern Great Plains region. The GSI system is implemented in a multiscale data assimilation framework using theWeather Research and Forecastingmodel at a cloud-resolving resolution of 2 km. From the fine-resolution three-dimensional fields, large-scale forcing is derived explicitly at grid-scale resolution; a subgrid-scale dynamic component is derived separately, representing subgrid-scale horizontal dynamic processes. Analyses show that the subgrid-scale dynamic component is often a major component over the large-scale forcing for grid scales larger than 200 km. The single-column model (SCM) of the Community AtmosphericModel version 5 is used to examine the impact of the grid-scale and subgrid-scale dynamic components on simulated precipitation and cloud fields associated with a mesoscale convective system. It is found that grid-scale size impacts simulated precipitation, resulting in an overestimation for grid scales of about 200 km but an underestimation for smaller grids. The subgrid-scale dynamic component has an appreciable impact on the simulations, suggesting that grid-scale and subgrid-scale dynamic components should be considered in the interpretation of SCM simulations. . © 2014. American Geophysical Union. All Rights Reserved."
"57197143203;6701500641;","Rock Surface Classification in a Mine Drift Using Multiscale Geometric Features",2015,"10.1109/LGRS.2015.2398814","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85027945513&doi=10.1109%2fLGRS.2015.2398814&partnerID=40&md5=ef428b657dcd7177be4e2e702f13e85b","Scale-dependent statistical depictions of surface morphology offer the potential to parameterize complex geometrical scaling relationships with greater detail than traditional fractal measures. Using multiscale operators, it is possible to identify points belonging to rough discontinuous surfaces in noisy point clouds solely on the basis of their local geometry. Many strategies for point cloud feature classification have been developed since the proliferation of laser scanning systems. Most of the techniques which are applicable to natural scenes employ external data sources such as hyperspectral imagery, return pulse intensity, and waveform data. In this letter, multiscale geometric parameters are used to identify individual point observations corresponding to rock surfaces in point clouds acquired by terrestrial laser scanning in scenes with man-made clutter and scanning artifacts. Three multiscale operators, namely, the approximate shape and density of a defined neighborhood and the distance of its mean point from its geometric center, are fused into a single feature vector. The procedure is demonstrated using real point cloud data acquired in a mine drift, with the goal of identifying points belonging to the rock face obscured by an overlying wire support mesh. Using the extra-trees classifier, extraneous returns caused by the mesh were excluded from the point cloud with a 97% success rate, while 87% of the desired surface points were retained. © 2004-2012 IEEE."
"54384072100;24485218400;7003278104;7006095466;7407016988;","Convective momentum transport associated with the Madden-Julian oscillation based on a reanalysis dataset",2015,"10.1175/JCLI-D-14-00570.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84932195004&doi=10.1175%2fJCLI-D-14-00570.1&partnerID=40&md5=35a761a96795a4410632c35c08d6de3f","A better understanding of multiscale interactions within the Madden-Julian oscillation (MJO), including momentum exchanges, is critical for improved MJO prediction skill. In this study, convective momentum transport (CMT) associatedwith theMJO is analyzed based on theNOAAClimate Forecast SystemReanalysis (CFSR). A three-layer vertical structure associated with the MJO, as previously suggested in the mesoscale momentum tendency profile based on global cloud-resolving model simulations, is evident in the subgrid-scale momentum tendency from the CFSR. Positive (negative) subgrid-scale momentum tendency anomalies are found near the surface, negative (positive) anomalies are found in the low to midtroposphere, and positive (negative) anomalies in the upper troposphere are found within and to the west (east) of the MJO convection. This tends to damp theMJOcirculation in the free atmosphere,while enhancing MJOwinds near the surface. In addition, it could also reduce theMJO eastward propagation speed and lead to the backward tilt with height in the observed MJO structure through a secondary circulation near the MJO center. Further analyses illustrate that this three-layer vertical structure in subgrid-scale momentum tendency largely balances the grid-scale momentum transport of the zonal wind component u, mainly through the transport of seasonal mean u by the MJO-scale vertical motion. Synoptic-scale systems, which were previously proposed to be essential for the u-momentumtransport of theMJO, however, are found to play aminor role for the total grid-scalemomentum tendency. The abovemomentumtendency structure is also confirmedwith theECMWFanalysis for the Year of Tropical Convection (YOTC) that lends confidence to these above results based on the CFSR. © 2015 American Meteorological Society."
"25822850900;26532224300;55934464100;56209845300;","Numerical simulations and measurements of a droplet size distribution in a turbulent vortex street",2014,"10.1127/0941-2948/2014/0570","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84925389184&doi=10.1127%2f0941-2948%2f2014%2f0570&partnerID=40&md5=02707236edc2d31f76c20c01a5898143","A turbulent vortex street in an air flow interacting with a disperse droplet population is investigated in a wind tunnel. Non-intrusive measurement techniques are used to obtain data for the air velocity and the droplet velocity. The process is modeled with a population balance system consisting of the incompressible Navier-Stokes equations and a population balance equation for the droplet size distribution. Numerical simulations are performed that rely on a variational multiscale method for turbulent flows, a direct discretization of the differential operator of the population balance equation, and a modern technique for the evaluation of the coalescence integrals. After having calibrated two unknown model parameters, a very good agreement of the experimental and numerical results can be observed. © 2014 The authors."
"36908360800;6603944096;6603678039;","Multiscale analysis of galactic dust emission using complex wavelet transforms - I. Separation of Gaussian and non-Gaussian fluctuations in herschel observations",2014,"10.1093/mnras/stu375","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84898782540&doi=10.1093%2fmnras%2fstu375&partnerID=40&md5=85593f0d74232a6317f76797573d6c10","We use anisotropic complex wavelet transforms to make a multiscale analysis of the distribution of fluctuations of dust emission at 250 μm from the Herschel infrared Galactic Plane Survey of the Herschel Space Observatory. By reproducing the Fourier power spectrum with complex wavelet transforms we show that different power distributions at each scale can have a significant effect on the measured power law. Moreover, with an iterative algorithm we separate the Gaussian and non-Gaussian part of wavelet coefficient distributions in each scale and azimuthal direction. The reconstructed map of non-Gaussian fluctuations is well correlated to small-scale structures of the 13CO emission map as well as its power spectrum which has a power-law index of -2.3. The Gaussian part of the map shows more diffuse structures with a steeper power law of -3.1. Non-Gaussian coefficients are almost undetectable at scales greater than ~0.15 arcmin-1 (~4-26 pc). This characteristic scale could be associated with the size of the larger molecular cloud in the region. We also demonstrate that exponentiated Gaussian random field cannot reproduce the flatter power law of the non-Gaussian component observed in the thermal dust emission, which seems to be a property of interstellar clouds. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society."
"24376765700;6603582339;","Cloud field segmentation via multiscale convexity analysis",2008,"10.1029/2007JD009369","https://www.scopus.com/inward/record.uri?eid=2-s2.0-50949112307&doi=10.1029%2f2007JD009369&partnerID=40&md5=5ecf154a02c089d28121e2b0b58d9806","Cloud fields retrieved from remotely sensed satellite data resemble functions depicting spectral values at each spatial position (x,y). Segmenting such cloud fields through a simple thresholding technique may not provide any structurally significant information about each segmented category. An approach based on the use of multiscale convexity analysis to derive structurally significant regions from cloud fields is addressed in this paper. This analysis requires (1) the generation of cloud fields at coarser resolutions and (2) the construction of convex hulls of cloud fields, at corresponding resolutions by employing multiscale morphologic opening transformation and half-plane closings with certain logical operations. The three basic parameters required from these generated multiscale phenomena in order to accomplish the structure-based segmentation include (1) the areas of multiscale cloud fields, (2) the areas of corresponding convex hulls, and (3) the estimation of convexity measures at corresponding resolutions by employing the areas of cloud fields and areas of corresponding convex hulls. These convexity measures computed for multiscale cloud fields are plotted as a function of the resolution imposed owing to multiscale opening to derive a causal relationship. The scaling exponents derived from these graphical plots are taken as the basis for (1) determining the transition zones between the regimes and (2) segmenting the cloud fields into morphologically significant regions. We demonstrated this approach on two different cloud fields retrieved from Moderate Resolution Imaging Spectroradiometer (MODIS) data. The segmented regions from these cloud fields possess different degrees of spatial complexities. As many macroscale and microscale atmospheric fields are classified according to spatial variability indexes, the framework proposed here would supplement those existing atmospheric field classification methodologies. Copyright 2008 by the American Geophysical Union."
"7404358451;","An unified approach to meteorological modelling based on multiple-scales asymptotics",2008,"10.5194/adgeo-15-23-2008","https://www.scopus.com/inward/record.uri?eid=2-s2.0-41249094043&doi=10.5194%2fadgeo-15-23-2008&partnerID=40&md5=f1bafc6e2c12f872a79c256c22249044","In 2003, the author suggested a mathematical framework for the derivation of reduced meteorological models at a Mathematics conference (5th ICIAM, Sydney, Australia), (Klein, 2004). The framework consists of (i) non-dimensionalization of the 3-D compressible flow equations on the rotating sphere, (ii) identification of universal non-dimensional parameters, (iii) distinguished limits between these and additional problem-specific parameters, and (iv) multiple scales expansions in the remaining small parameter &epsilon;. This parameter may be interpreted as the cubic root of the centripetal acceleration due to the Earth's rotation divided by the acceleration of gravity, see also Keller (1951), Eq. (10). For the mojority of reduced models of theoretical meteorology that we have come across, the approach allowed us to generate systematic derivations starting directly from the 3-D compressible flow equations on the rotating sphere. The framework's potential fully shows in multiscale interaction studies such as Klein (2006), in which we incorporated bulk microphysics closures for moist processes and derived scale interaction models for deep convection. Currently, we study the structure, evolution, and motion of Hurricane strength H1/H2 vortices (Mikusky, 2007), large-scale stratocumulus cloud decks, and planetary-synoptic scale interaction models which should be relevant for Earth System Models of Intermediate Complexity (EMICs). Here we summarize the general framework and use the example of quasi-geostrophic theory to demonstrate its application."
"6602453302;","Synoptic-scale transport of ozone into Southern Ontario",2007,"10.1016/j.atmosenv.2007.07.019","https://www.scopus.com/inward/record.uri?eid=2-s2.0-36348963602&doi=10.1016%2fj.atmosenv.2007.07.019&partnerID=40&md5=6a195884ab6ab527335048c8acdc6ec2","This study focuses on synoptic-scale transport of ozone as it affects Southern Ontario. This process has been analyzed for the summer in 2001, as an example period of a frequent event that usually occurs during summer in this region. The work was carried out using the mesoscale modeling system generation 5 (MM5)/sparse matrix operator kernel emission modeling system (SMOKE)/community multiscale air quality (CMAQ) regional air quality modeling system, together with observational data from monitoring stations located throughout the modeling domain. Other different analyses have been carried out to supply more information apart from that obtained by the modeling system. A back-trajectory cluster methodology was used to evaluate the magnitude of the effects studied and an analysis of wind direction and cloud cover revealed a significant correlation with ozone concentration (R2=0.5-0.6). Synoptic sea-surface level pressure (SLP) patterns were also analyzed to examine other meteorological aspects. The contribution of natural background ozone to the total amount within the region was compared with that from synoptic-scale transport. The influence of emission of pollutants from selected areas on ozone concentrations in Southern Ontario was also analyzed. As relevant results of these analyses, the model predicts that background ozone is the largest contribution to the ground-level ozone concentration during days in which low values were recorded. However, when smog episodes occurred, the model predicts that around 60% of the ozone formed by anthropogenic emissions of pollutants is due to releases from nearby US states. © 2007 Elsevier Ltd. All rights reserved."
"57204396783;57190372479;57192705696;12785706100;15034793900;","TGNet: Geometric Graph CNN on 3-D Point Cloud Segmentation",2020,"10.1109/TGRS.2019.2958517","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077294382&doi=10.1109%2fTGRS.2019.2958517&partnerID=40&md5=7445eb7bcc649fc8c2042ce9936afff6","Recent geometric deep learning works define convolution operations in local regions and have enjoyed remarkable success on non-Euclidean data, including graph and point clouds. However, the high-level geometric correlations between the input and its neighboring coordinates or features are not fully exploited, resulting in suboptimal segmentation performance. In this article, we propose a novel graph convolution architecture, which we term as Taylor Gaussian mixture model (GMM) network (TGNet), to efficiently learn expressive and compositional local geometric features from point clouds. The TGNet is composed of basic geometric units, TGConv, that conduct local convolution on irregular point sets and are parametrized by a family of filters. Specifically, these filters are defined as the products of the local point features and the neighboring geometric features extracted from local coordinates. These geometric features are expressed by Gaussian weighted Taylor kernels. Then, a parametric pooling layer aggregates TGConv features to generate new feature vectors for each point. TGNet employs TGConv on multiscale neighborhoods to extract coarse-to-fine semantic deep features while improving its scale invariance. Additionally, a conditional random field (CRF) is adopted within the output layer to further improve the segmentation results. Using three point cloud data sets, qualitative and quantitative experimental results demonstrate that the proposed method achieves 62.2% average accuracy on ScanNet, 57.8% and 68.17% mean intersection over union (mIoU) on Stanford Large-Scale 3D Indoor Spaces (S3DIS) and Paris-Lille-3D data sets, respectively. © 1980-2012 IEEE."
"57190337168;6505516700;","Enhancing image-based multiscale heritage recording with near-infrared data",2020,"10.3390/ijgi9040269","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85083778155&doi=10.3390%2fijgi9040269&partnerID=40&md5=1ef3f6692bd9c2c26a60a763404e5d60","Passive sensors, operating in the visible (VIS) spectrum, have widely been used towards the trans-disciplinary documentation, understanding, and protection of tangible cultural heritage (CH). Although, many heritage science fields benefit significantly from additional information that can be acquired in the near-infrared (NIR) spectrum. NIR imagery, captured for heritage applications, has been mostly investigated with two-dimensional (2D) approaches or by 2D-tothree- dimensional (3D) integrations following complicated techniques, including expensive imaging sensors and setups. The availability of high-resolution digital modified cameras and software implementations of Structure-from-Motion (SfM) and Multiple-View-Stereo (MVS) algorithms, has made the production of models with spectral textures more feasible than ever. In this research, a short review of image-based 3D modeling with NIR data is attempted. The authors aim to investigate the use of near-infrared imagery from relatively low-cost modified sensors for heritage digitization, alongside the usefulness of spectral textures produced, oriented towards heritage science. Therefore, thorough experimentation and assessment with different software are conducted and presented, utilizing NIR imagery and SfM/MVS methods. Dense 3D point clouds and textured meshes have been produced and evaluated for their metric validity and radiometric quality, comparing to results produced from VIS imagery. The datasets employed come from heritage assets of different dimensions, from an archaeological site to a medium-sized artwork, to evaluate implementation on different levels of accuracy and specifications of texture resolution. © 2020 by the authors. Licensee MDPI, Basel, Switzerland."
"57200555819;57211430607;57126877800;56506111400;7005693588;","Directionally constrained fully convolutional neural network for airborne LiDAR point cloud classification",2020,"10.1016/j.isprsjprs.2020.02.004","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85079552935&doi=10.1016%2fj.isprsjprs.2020.02.004&partnerID=40&md5=9e82c0e57ce7b67b4a9e2ac64403189c","Point cloud classification plays an important role in a wide range of airborne light detection and ranging (LiDAR) applications, such as topographic mapping, forest monitoring, power line detection, and road detection. However, due to the sensor noise, high redundancy, incompleteness, and complexity of airborne LiDAR systems, point cloud classification is challenging. Traditional point cloud classification methods mostly focus on the development of handcrafted point geometry features and employ machine learning-based classification models to conduct point classification. In recent years, the advances of deep learning models have caused researchers to shift their focus towards machine learning-based models, specifically deep neural networks, to classify airborne LiDAR point clouds. These learning-based methods start by transforming the unstructured 3D point sets to regular 2D representations, such as collections of feature images, and then employ a 2D CNN for point classification. Moreover, these methods usually need to calculate additional local geometry features, such as planarity, sphericity and roughness, to make use of the local structural information in the original 3D space. Nonetheless, the 3D to 2D conversion results in information loss. In this paper, we propose a directionally constrained fully convolutional neural network (D-FCN) that can take the original 3D coordinates and LiDAR intensity as input; thus, it can directly apply to unstructured 3D point clouds for semantic labeling. Specifically, we first introduce a novel directionally constrained point convolution (D-Conv) module to extract locally representative features of 3D point sets from the projected 2D receptive fields. To make full use of the orientation information of neighborhood points, the proposed D-Conv module performs convolution in an orientation-aware manner by using a directionally constrained nearest neighborhood search. Then, we design a multiscale fully convolutional neural network with downsampling and upsampling blocks to enable multiscale point feature learning. The proposed D-FCN model can therefore process input point cloud with arbitrary sizes and directly predict the semantic labels for all the input points in an end-to-end manner. Without involving additional geometry features as input, the proposed method demonstrates superior performance on the International Society for Photogrammetry and Remote Sensing (ISPRS) 3D labeling benchmark dataset. The results show that our model achieves a new state-of-the-art performance on powerline, car, and facade categories. Moreover, to demonstrate the generalization abilities of the proposed method, we conduct further experiments on the 2019 Data Fusion Contest Dataset. Our proposed method achieves superior performance than the comparing methods and accomplishes an overall accuracy of 95.6% and an average F1 score of 0.810. © 2020 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS)"
"57188866963;57192156759;57210687618;23991212200;","Comparing Convective Self-Aggregation in Idealized Models to Observed Moist Static Energy Variability Near the Equator",2019,"10.1029/2019GL084130","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85071749544&doi=10.1029%2f2019GL084130&partnerID=40&md5=947a6b25a6b7dd3fddf9defcfebe4555","Idealized convection-permitting simulations of radiative-convective equilibrium have become a popular tool for understanding the physical processes leading to horizontal variability of tropical water vapor and rainfall. However, the applicability of idealized simulations to nature is still unclear given that important processes are typically neglected, such as lateral water vapor advection by extratropical intrusions, or interactive ocean coupling. Here, we exploit spectral analysis to compactly summarize the multiscale processes supporting convective aggregation. By applying this framework to high-resolution reanalysis data and satellite observations in addition to idealized simulations, we compare convective-aggregation processes across horizontal scales and data sets. The results affirm the validity of the radiative-convective equilibrium simulations as an analogy to the real world. Column moist static energy tendencies share similar signs and scale selectivity in convection-permitting models and observations: Radiation increases variance at wavelengths above 1,000 km, while advection damps variance across wavelengths, and surface fluxes mostly reduce variance between 1,000 and 10,000 km. ©2019. American Geophysical Union. All Rights Reserved."
"57194602651;55578187900;57209349012;7005279146;","UNSUPERVISED WINDOW EXTRACTION from PHOTOGRAMMETRIC POINT CLOUDS with THERMAL ATTRIBUTES",2019,"10.5194/isprs-annals-IV-2-W5-45-2019","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85067421008&doi=10.5194%2fisprs-annals-IV-2-W5-45-2019&partnerID=40&md5=d24b9ee789410479e90359ef79457f0d","The automatic extraction of windows from photogrammetric data has achieved increasing attention in recent times. An unsupervised windows extraction approach from photogrammetric point clouds with thermal attributes is proposed in this study. First, point cloud segmentation is conducted by a popular workflow: Multiscale supervoxel generation is applied to the image-based 3D point cloud, followed by region growing and energy optimization using spatial positions and thermal attributes of the raw points. Afterwards, an object-based feature (window index) is extracted using the average thermal attribute and the size of the object. Next, thresholding is applied to extract initial window regions. Finally, several criterions are applied to further refine the extraction results. For practical validation, the approach is evaluated on an art nouveau building row façade located at Dresden, Germany. © Authors 2019."
"24757719500;57195307414;8571446100;56207914800;55958111400;","A multiscale study of star formation in Messier 33",2019,"10.1093/mnras/sty3091","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85068925322&doi=10.1093%2fmnras%2fsty3091&partnerID=40&md5=7ba6da01cc460d86bff0f923767c776e","For the Local Group Scd galaxy M 33 this paper presents a multiscale study of the relationship between the monochromatic star formation rate (SFR) estimator based on 12 μm emission and the total SFR estimator based on a combination of far-ultraviolet and 24 μm emission. We show the 12 μm emission to be a linear estimator of total SFR on spatial scales from 782 pc down to 49 pc, over almost four magnitudes in SFR. These results therefore extend to sub-kpc length-scales the analogous results from other studies for global length-scales. We use high-resolution H I and 12CO(J = 2 − 1) image sets from the literature to compare the star formation to the neutral gas. For the full range of length-scales we find well-defined power-law relationships between 12 μm-derived SFR surface densities and neutral gas surface densities. For the H2 gas component almost all correlations are consistent with being linear. No evidence is found for a breakdown in the star formation law at small length-scales in M 33 reported by other authors. We show that the average star formation efficiency in M 33 is roughly 10−9 yr−1 and that it remains constant down to giant molecular cloud length-scales. Toomre and shear-based models of the star formation threshold are shown to inaccurately account for the star formation activity in the inner disc of M 33. Finally, we clearly show that the H I saturation limit of ≈9 M☉ pc−2 reported in the literature for other galaxies is not an intrinsic property of M 33 - it is systematically introduced as an artefact of spatially smoothing the data. © 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society."
"56612517400;6701562113;","Precipitation Partitioning in Multiscale Atmospheric Simulations: Impacts of Stability Restoration Methods",2018,"10.1029/2018JD028710","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053554212&doi=10.1029%2f2018JD028710&partnerID=40&md5=bc1c56376388787a598ecd3f2401a596","Proper simulation of high-resolution surface precipitation distribution and variability is important to local aspects of environmental pollution and climate. Global and regional climate and weather models routinely evaluate total precipitation using available measurements, but quantitative evaluation of contributions by the individual components (convective and nonconvective) to the total precipitation is not routinely performed. Wet bias in one component can alleviate dry bias in the other component, making the total precipitation look comparable to measurements, leading to an invisible bias. To study this aspect, Tropical Rainfall Measuring Mission (TRMM) measurements for precipitation components were used to quantitatively evaluate convective fractions simulated by a cumulus parameterization scheme in a regional climate simulation using 12-km grid spacing. Results indicated a wet bias in convective precipitation as compared to TRMM measurements. This wet bias helped to counter a dry bias in grid-scale precipitation and led to a total precipitation comparable to Parameter-elevation Regressions on Independent Slopes Model and TRMM measurements. A new formulation has been developed for convective cloud adjustment time scale alleviating wet bias in convective precipitation when compared to the old formulation and TRMM measurements. Results for different grid spacing also indicate that the new method produces lower subgrid-scale precipitation with overall better precipitation estimates. Our results also suggest that evaluating both components of the surface precipitation rather than just the total itself can inform a need to improve cloud formulations, as demonstrated in this study. This study calls for the development of methods to routinely produce measurements for precipitation components that help evaluating global and regional climate and weather models. Published 2018. This article is a US Government work and is in the public domain in the USA."
"57203690376;8916335600;6603381720;","Investigating the relative contributions of charge deposition and turbulence in organizing charge within a thunderstorm",2018,"10.1175/JAS-D-18-0007.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85052625954&doi=10.1175%2fJAS-D-18-0007.1&partnerID=40&md5=17dbc737ce8b0b9eca376c52804291ee","Large-eddy-resolving simulations using the Collaborative Model for Multiscale Atmospheric Simulation (COMMAS), which contains microphysical charging and branched-lightning parameterizations, produce much more complex net charge structures than conventionally visualized from previous observations, simulations, and conceptual diagrams. Many processes contribute to the hydrometeor charge budget within a thunderstorm, including advection, hydrometeor differential sedimentation, subgrid turbulent mixing and diffusion, ion drift, microphysical separation, and the attachment of ion charge deposited by the lightning channel. The lightning deposition, sedimentation, and noninductive charging tendencies contribute the most overall charge at relatively large scales, while the advection tendency, from resolved turbulence, provides the most ""texture"" at small scales to the net charge density near the updraft region of the storm. The scale separation increases for stronger storm simulations. In aggregate, lightning deposition and sedimentation resemble the smoother distribution of the electric potential, while evidence suggests individual flashes could be responding to the fine texture in the net charge. The clear scale separation between the advection and other net charge tendencies suggest the charge advection is most capable of providing net charge texture; however, a clear-cut causality is not obtained from this study. © 2018 American Meteorological Society."
"57195576398;25941200000;35572096100;9239331500;24337947000;56009810800;35317714900;7003557662;6602681732;6602922400;12800966700;7003535385;8397494800;35567153700;6603631763;","Evaluation of a high-resolution numerical weather prediction model's simulated clouds using observations from CloudSat, GOES-13 and in situ aircraft",2018,"10.1002/qj.3318","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054533459&doi=10.1002%2fqj.3318&partnerID=40&md5=a777a4a748952ef2711a1970af7f1d10","This study aimed to assess tropical cloud properties predicted by Environment and Climate Change Canada's Global Environmental Multiscale (GEM) model when run with the Milbrandt–Yau double-moment cloud microphysical scheme and one-way nesting that culminated at a (∼300 km)2 inner domain with 0.25 km horizontal grid spacing. The assessment utilized satellite and in situ data collected during the High Ice Water Content (HIWC) and High Altitude Ice Crystals (HAIC) projects for a mesoscale convective system on 16 May 2015 over French Guiana. Data from CloudSat's cloud-profiling radar and GOES-13's imager were compared to data either simulated directly by GEM or produced by operating on GEM's cloud data with both the CFMIP (Cloud Feedback Model Intercomparison Project) Observation Simulator Package (COSP) instrument simulator and a three-dimensional Monte Carlo solar radiative transfer model. In situ observations were made from research aircraft – Canada's National Research Council Convair-580 and the French SAFIRE Falcon-20 – whose flight paths were aligned with CloudSat's ground-track. Spatial and temporal shifts of clouds simulated by GEM compared well to GOES-13 imagery. There are, however, differences between simulated and observed amounts of high and low cloud. While GEM did well at predicting ranges of ice-water content (IWC) near 11 km altitude (Falcon-20), it produces too much graupel and snow near 7 km (Convair-580). This produced large differences between CloudSat's and COSP-generated radar reflectivities and two-way attenuations. On the other hand, CloudSat's inferred values of IWC agree well with in situ samples at both altitudes. Generally, GEM's visible reflectances exceeded GOES-13's on account of having produced too much low-level liquid cloud. It is expected that GEM's disproportioning of cloud hydrometeors will improve once it includes a better representation of secondary ice production. © 2018 Her Majesty the Queen in Right of Canada. Quarterly Journal of the Royal Meteorological Society © 2018 Royal Meteorological Society"
"57160277800;57193444767;57193495356;16235266600;","Detection of Rock Discontinuity Traces Using Terrestrial LiDAR Data and Space-Frequency Transforms",2018,"10.1007/s10706-017-0430-6","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85038607293&doi=10.1007%2fs10706-017-0430-6&partnerID=40&md5=dfe8f18bf1402375847ff815cbd312ae","Part of the rockmass assessment and its application in numerical modelling, within the geotechnical engineering field, is acquiring information such as discontinuity number, density, intensity, size etc., which can be obtained by mapping fracture traces on exposed rockmass surfaces and processing of the recorded field data. Moving past from traditional mapping techniques in the field, fracture traces can be extracted from terrestrial light detection and ranging (LiDAR) point-clouds or LiDAR-derived surface models. However, similarly to field mapping, the extraction of fracture-traces is often done manually. This is an arduous and timely task in most cases. The automatic-detection of such traces is an emerging topic in geotechnical engineering; however, existing methods focus solely on the spatial domain. Space-frequency representations are ideal for detecting singularities due to their localization in space and frequency. Furthermore, they allow multiscale analysis, which is important for isolating LiDAR-data noise and weak traces in lower scales. In this study, three space-frequency transforms are evaluated, namely, (1) wavelet, (2) contourlet, and (3) shearlet. In addition, the well-known methods of Sobel, Prewitt, and Canny for edge detection are used for comparison purposes. The performance of the different edge-detection methods is tested using data collected from the Brockville Tunnel in Ontario, Canada. Numerical and visual assessment show that contourlets and shearlets achieve the highest agreement with manually-extracted traces that are used for validation. The two methods, along with minimal user interaction, can be used in order to increase the efficiency of rockmass mapping and geometric modelling in stability assessment of tunnels, mines, slopes, and related applications. © 2017, Springer International Publishing AG, part of Springer Nature."
"56434851400;7004978125;","Upscale impact of mesoscale disturbances of tropical convection on convectively coupled Kelvin waves",2018,"10.1175/JAS-D-17-0178.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85040930944&doi=10.1175%2fJAS-D-17-0178.1&partnerID=40&md5=a9bb6238a2ef43069f2800228e5d6567","Tropical convection associated with convectively coupled Kelvin waves (CCKWs) is typically organized by an eastward-moving synoptic-scale convective envelope with numerous embedded westward-moving mesoscale disturbances. Such a multiscale structure of tropical convection is a challenge for present-day cloud-resolving simulations and its representation in global climate models. It is of central importance to assess the upscale impact of mesoscale disturbances on CCKWs as mesoscale disturbances propagate at various tilt angles and speeds. Besides, it is still poorly understood whether the front-to-rear-tilted vertical structure of CCKWs can be induced by the upscale impact of mesoscale disturbances in the presence of upright mean heating. Here, a simple multiscale model is used to capture this multiscale structure, where mesoscale fluctuations are directly driven by mesoscale heating and synoptic-scale circulation is forced by mean heating and eddy transfer of momentum and temperature. The results show that the upscale impact of mesoscale disturbances that propagate at tilt angles of 110°-250° induces negative lower-tropospheric potential temperature anomalies in the leading edge, providing favorable conditions for shallow convection in a moist environment, while the remaining tilt-angle cases have opposite effects. Even in the presence of upright mean heating, the front-to-rear-tilted synoptic-scale circulation can still be induced by eddy terms at tilt angles of 120°-240°. In the case with fast-propagating mesoscale heating, positive potential temperature anomalies are induced in the lower troposphere, suppressing convection in a moist environment. This simple model also reproduces convective momentum transport and CCKWs in agreement with results from a recent cloud-resolving simulation. © 2018 American Meteorological Society."
"7403282069;8977001000;","Understanding the tropical cloud feedback from an analysis of the circulation and stability regimes simulated from an upgraded multiscale modeling framework",2016,"10.1002/2016MS000767","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85006287864&doi=10.1002%2f2016MS000767&partnerID=40&md5=b6a561d44ed6b8417e2b52b7d6ee8c0f","As revealed from studies using conventional general circulation models (GCMs), the thermodynamic contribution to the tropical cloud feedback dominates the dynamic contribution, but these models have difficulty in simulating the subsidence regimes in the tropics. In this study, we analyze the tropical cloud feedback from a 2 K sea surface temperature (SST) perturbation experiment performed with a multiscale modeling framework (MMF). The MMF explicitly represents cloud processes using 2-D cloud-resolving models with an advanced higher-order turbulence closure in each atmospheric column of the host GCM. We sort the monthly mean cloud properties and cloud radiative effects according to circulation and stability regimes. We find that the regime-sorted dynamic changes dominate the thermodynamic changes in terms of the absolute magnitude. The dynamic changes in the weak subsidence regimes exhibit strong negative cloud feedback due to increases in shallow cumulus and deep clouds while those in strongly convective and moderate-to-strong subsidence regimes have opposite signs, resulting in a small contribution to cloud feedback. On the other hand, the thermodynamic changes are large due to decreases in stratocumulus clouds in the moderate-to-strong subsidence regimes with small opposite changes in the weak subsidence and strongly convective regimes, resulting in a relatively large contribution to positive cloud feedback. The dynamic and thermodynamic changes contribute equally to positive cloud feedback and are relatively insensitive to stability in the moderate-to-strong subsidence regimes. But they are sensitive to stability changes from the SST increase in convective and weak subsidence regimes. These results have implications for interpreting cloud feedback mechanisms. Published 2016. This article is a U.S. Government work and is in the public domain in the USA."
"57190870452;55716217300;8420514500;55473757400;","The multiscale factors favorable for a persistent heavy rain event over Hainan Island in October 2010",2016,"10.1007/s13351-016-6005-2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84983670575&doi=10.1007%2fs13351-016-6005-2&partnerID=40&md5=c5f64c9439d5cd2a5f3a0bca3163a588","A case study is presented of the multiscale characteristics that produced the record-breaking persistent heavy rainfall event (PHRE) over Hainan Island, northern South China Sea (SCS), in autumn 2010. The study documents several key weather systems, from planetary scale to mesoscale, that contributed to the extreme rainfall during this event. The main findings of this study are as follows. First, the convectively active phase of the MJO was favorable for the establishment of a cyclonic circulation and the northward expansion of the Intertropical Convergence Zone (ITCZ). The active disturbances in the northward ITCZ helped direct abundant moisture from adjacent oceans towards Hainan Island continuously throughout the event, where it interacted with cold air from the midlatitudes and caused heavy rain. Second, the 8-day-long PHRE can be divided into three processes according to different synoptic systems: peripheral cloud clusters of a tropical depression-type disturbance over the central SCS in process 1; interactions between the abnormally far north ITCZ and the invading cold air in process 2; and the newly formed tropical depression near Hainan Island in process 3. In the relatively stable synoptic background of each process, meso-α- and meso-β-scale cloud clusters repeatedly traveled along the same path to Hainan Island. Finally, based on these analyses, a conceptual model is proposed for this type of PHRE in autumn over the northern SCS, which demonstrates the influences of multiscale systems. © 2016, The Chinese Meteorological Society and Springer-Verlag Berlin Heidelberg."
"57219529090;57217606033;23004944100;","Terrestrial and unmanned aerial system imagery for deriving photogrammetric three-dimensional point clouds and volume models of mass wasting sites",2016,"10.1117/1.JRS.10.026029","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84973373536&doi=10.1117%2f1.JRS.10.026029&partnerID=40&md5=dd1538fea931038a51fa5fee2ead6f95","Three-dimensional (3-D) geodata of mass wasting sites are important to model surfaces, volumes, and their changes over time. With a photogrammetric approach commonly known as structure from motion, 3-D point clouds can be derived from image collections in a straightforward way. The quality of point clouds covering a quarry dump derived from terrestrial and aerial imagery is compared and assessed. A comprehensive set of quality indicators is calculated and compared to surveyed reference data and to a terrestrial LiDAR point cloud. The examined indicators are completeness of coverage, point density, vertical accuracy, multiscale point cloud distance, scaling accuracy, and dump volume. It is found that the photogrammetric datasets generally represent the examined dump well with, for example, an area coverage of up to 90% and 100% in case of terrestrial and aerial imagery, respectively, a maximum scaling difference of 0.62%, and volume estimations reaching up to 100% of the LiDAR reference. Combining the advantages of 3-D geodata derived from terrestrial (high detail, accurate volume calculation even with a small number of input images) and aerial images (high coverage) can be a promising method to further improve the quality of 3-D geodata derived with low-cost approaches. © 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)."
"8688004400;6603263640;7004978125;57193882808;","Multiscale interactions in an idealized walker cell: Analysis with isentropic streamfunctions",2016,"10.1175/JAS-D-15-0070.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84962214158&doi=10.1175%2fJAS-D-15-0070.1&partnerID=40&md5=435e8c0cd9e6afdb6d153b173bf65e44","A new approach for analyzing multiscale properties of the atmospheric flow is proposed in this study. For that, the recently introduced isentropic streamfunctions are employed here for scale decomposition with Haar wavelets. This method is applied subsequently to a cloud-resolving simulation of a planetary Walker cell characterized by pronounced multiscale flow. The resulting set of isentropic streamfunctions-obtained at the convective, meso-, synoptic, and planetary scales-capture many important features of the across-scale interactions within an idealized Walker circulation. The convective scale is associated with the shallow, congestus, and deep clouds, which jointly dominate the upward mass flux in the lower troposphere. The synoptic and planetary scales play important roles in extending mass transport to the upper troposphere, where the corresponding streamfunctions mainly capture the first baroclinic mode associated with large-scale overturning circulation. The intermediate-scale features of the flow, such as anvil clouds associated with organized convective systems, are extracted with the mesoscale and synoptic-scale isentropic streamfunctions. Multiscale isentropic streamfunctions are also used to extract salient mechanisms that underlie the low-frequency variability of the Walker cell. In particular, the lag of a few days of the planetary scale behind the convective scale indicates the importance of the convective scale in moistening the atmosphere and strengthening the planetary-scale overturning circulation. Furthermore, the mesoscale and synoptic scale lags behind the planetary scale reflect the strong dependence of convective organization on the background shear. © 2016 American Meteorological Society."
"8856939100;7201504886;7404358451;","Multiscale asymptotics analysis for the mesoscale dynamics of cloud-topped boundary layers",2011,"10.1175/2010JAS3469.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79953197964&doi=10.1175%2f2010JAS3469.1&partnerID=40&md5=cbdb05e22a69bba84d3a8c0b8d80c5a3","This paper presents the derivation of a model to explore the coupling between the dynamic and thermodynamic processes of a cloud-topped boundary layer on mesoscales using a formal multiscale asymptotic approach. The derived equations show how the anomalies in the heat, moisture, and mass budgets in the boundary layer affect boundary layer motions, and how these motions can organize and amplify (or damp) such anomalies. The thermodynamics equations are similar to those that have been suggested in mixed layer studies; that is, the evolution of the thermodynamics variables depends on the surface heat and moisture fluxes, cloud-top radiative cooling rate, temperature, and moisture jumps across the capping inversion. However, these equations are coupled to the dynamics equation through the entrainment rate at the top of the cloud deck. The entrainment rate is parameterized from results obtained in laboratory experiments and clearly shows the dependence on the velocity perturbation, which in turn strongly depends on the horizontal gradient of the thermodynamics variables. The derived entrainment rate is applicable when the thermal jump at cloud top is sufficiently weak and the velocity jump is on the order of the velocity perturbation. Aside from some initial analyses of the main balances in steady-state solutions, the mathematical properties and physical characteristics of the system of equations will be explored in future papers. © 2011 American Meteorological Society."
"14032370500;14031407200;7201522137;","Changing surface conditions at Kilimanjaro indicated from multiscale imagery",2009,"10.1659/mrd.981","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77949359365&doi=10.1659%2fmrd.981&partnerID=40&md5=dba0d488dc65eaa63f6ca6877b234ea1","The shrinking glacier atop Kilimanjaro has received much attention as it is one of the few remaining tropical glaciers in the world. Physical drivers ranging from changes in temperature and humidity to shifts in cloud coverage and radiation have been attributed to reducing the ice mass. Studies have utilized varying methods and often use point data sources that tend to be spatially and temporally poor in the region. The objective of this study was to use complementing remote sensing data sets with systematic measurements to delineate ice cap fluctuations and land surface phenology on Kilimanjaro over the past two decades. Multitemporal, fine-scale Landsat imagery (30 m) showed approximately a 70% reduction in ice coverage since 1976. High-frequency (bimonthly) image analysis conducted along a human activity-elevation ecocline showed that the entire mountain, including the subalpine and alpine regions, has undergone an increase in vegetative signal indicating a ""greening up"" of Kilimanjaro over the past two decades. In addition, upper elevations of Kilimanjaro have undergone a temporal shift, or lengthening, in dry season phenology on the order of one month over the past two decades. The shift in dry season timing is concordant with maximum ablation periods. Overall, this study provides insight into land surface trends at resolutions that are currently lacking in Kilimanjaro climate change analyses. © 2009 by the authors."
"55880561900;6701754792;6506416572;","Pacific and Atlantic 'bomb-like' deepenings in mature phase: A comparative study",1999,"10.1256/smsqj.56117","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0342657760&doi=10.1256%2fsmsqj.56117&partnerID=40&md5=256d93cafc850188df00758016ce12a4","The mesoscale dynamics of a secondary cyclone sampled during the field phase of the Fronts and Atlantic Storm-Track EXperiment (FASTEX) are documented using airborne Doppler radar data. The high quality of the mesoscale airborne Doppler dataset collected within this secondary cyclone is highlighted. This study demonsrates, however, the need to combine in the near future airborne Doppler radar and dropsonde measurements, in order to access multiscale processes involved in the mature stage of this FASTEX cyclone both in clear-air and in precipitating regions. The studied secondary cyclone developed on the trailing cold front of a parent low situated over Greenland, and underwent the most explosive deepening (roughly -54 mb in 24 hours) sampled in the multiscale sampling area during FASTEX. The main flows responsible for the mesoscale organization of the cyclone are: a warm airflow emerging from the base of the synoptic warm conveyor belt that generates the most active part of the cloud head; a dry intrusion approaching in the dry slot the cyclone centre; a cold conveyor belt that contributes to the upward mass transport towards the upper part of the polar-front cloud band; and a cold northerly flow in the western part of the cloud head, which tends to wrap around the low centre and is likely to release convective instability through air-sea interactions. This study also documents a slight shift in position between the high vertical-vorticity core associated with the active part of the cloud head and the location of the pressure minimum. The detailed three-dimensional structure of this Atlantic secondary cyclone is also compared with that gathered within another 'bomb-like' deepening (defined as more than a 24 mb surface pressure drop in 24 hours) observed over the Pacific ocean during the Coastal Observation and Simulation with Topography (COAST) experiment. Some similarities are found. The main differences appear to be linked to the warm seclusion that is exclusive to the studied Pacific cyclone. More pronounced ascending motions are found within the cloud head of the Pacific 'reference' case, and the deepening results from a more constructive effect of geostrophic and non-geostrophic processes than for the Atlantic 'reference' case."
"6603431534;14019153700;7006204393;56084472800;35389411400;20433705700;26423829900;57217983169;57190584167;19337612500;8658386900;57211721176;36342344200;7006303509;7103373860;","The ARM radar network: At the leading edge of cloud and precipitation observations",2020,"10.1175/BAMS-D-18-0288.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85086220747&doi=10.1175%2fBAMS-D-18-0288.1&partnerID=40&md5=0bd95b1da7d0b1f514d552f6606573fe","Improving our ability to predict future weather and climate conditions is strongly linked to achieving significant advancements in our understanding of cloud and precipitation processes. Observations are critical to making these advancements because they both improve our understanding of these processes and provide constraints on numerical models. Historically, instruments for observing cloud properties have limited cloud-aerosol investigations to a small subset of cloud-process interactions. To address these challenges, the last decade has seen the U.S. DOE ARM facility significantly upgrade and expand its surveillance radar capabilities toward providing holistic and multiscale observations of clouds and precipitation. These upgrades include radars that operate at four frequency bands covering a wide range of scattering regimes, improving upon the information contained in earlier ARM observations. The traditional ARM emphasis on the vertical column is maintained, providing more comprehensive, calibrated, and multiparametric measurements of clouds and precipitation. In addition, the ARM radar network now features multiple scanning dual-polarization Doppler radars to exploit polarimetric and multi-Doppler capabilities that provide a wealth of information on storm microphysics and dynamics under a wide range of conditions. Although the diversity in wavelengths and detection capabilities are unprecedented, there is still considerable work ahead before the full potential of these radar advancements is realized. This includes synergy with other observations, improved forward and inverse modeling methods, and well-designed data-model integration methods. The overarching goal is to provide a comprehensive characterization of a complete volume of the cloudy atmosphere and to act as a natural laboratory for the study of cloud processes. © 2020 American Meteorological Society."
"57198945375;57203579757;57193856591;56893485300;35316923500;8382949200;","Neighborhood-and object-based probabilistic verification of the OU MAP ensemble forecasts during 2017 and 2018 hazardous weather testbeds",2020,"10.1175/WAF-D-19-0060.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85081583973&doi=10.1175%2fWAF-D-19-0060.1&partnerID=40&md5=e071b5e58a2d17d1aa30fdb5c7505b18","An object-based probabilistic (OBPROB) forecasting framework is developed and applied, together with a more traditional neighborhood-based framework, to convection-permitting ensemble forecasts produced by the University of Oklahoma (OU) Multiscale data Assimilation and Predictability (MAP) laboratory during the 2017 and 2018 NOAA Hazardous Weather Testbed Spring Forecasting Experiments. Case studies from 2017 are used for parameter tuning and demonstration of methodology, while the 2018 ensemble forecasts are systematically verified. The 2017 case study demonstrates that the OBPROB forecast product can provide a unique tool to operational forecasters that includes convective-scale details such as storm mode and morphology, which are typically lost in neighborhood-based methods, while also providing quantitative ensemble probabilistic guidance about those details in a more easily interpretable format than the more commonly used paintball plots. The case study also demonstrates that objective verification metrics reveal different relative performance of the ensemble at different forecast lead times depending on the verification framework (i.e., object versus neighborhood) because of the different features emphasized by object-and neighborhood-based evaluations. Both frameworks are then used for a systematic evaluation of 26 forecasts from the spring of 2018. The OBPROB forecast verification as configured in this study shows less sensitivity to forecast lead time than the neighborhood forecasts. Both frameworks indicate a need for probabilistic calibration to improve ensemble reliability. However, lower ensemble discrimination for OBPROB than the neighborhood-based forecasts is also noted. © 2020 American Meteorological Society."
"57160105200;56087837500;55713797200;57216330044;57218770918;7006890666;6603119574;7006576695;","The RWST, a comprehensive statistical description of the non-Gaussian structures in the ISM",2019,"10.1051/0004-6361/201834975","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077555085&doi=10.1051%2f0004-6361%2f201834975&partnerID=40&md5=9a9d029397d9ee51bd31f209f3d46a3d","The interstellar medium (ISM) is a complex nonlinear system governed by the interplay between gravity and magneto-hydrodynamics, as well as radiative, thermodynamical, and chemical processes. Our understanding of it mostly progresses through observations and numerical simulations, and a quantitative comparison between these two approaches requires a generic and comprehensive statistical description of the emerging structures. The goal of this paper is to build such a description, with the purpose of permitting an efficient comparison that is independent of any specific prior or model. We started from the wavelet scattering transform (WST), a low-variance statistical description of non-Gaussian processes, which was developed in data science and encodes long-range interactions through a hierarchical multiscale approach based on the wavelet transform. We performed a reduction of the WST through a fit of its angular dependencies. This allowed us to gather most of the information it contains into a few components whose physical meanings are identified and describe for instance isotropic and anisotropic behaviours. The result of this paper is the reduced wavelet scattering transform (RWST), a statistical description with a small number of coefficients that characterizes complex structures arising from nonlinear phenomena, in particular interstellar magnetohydrodynamical (MHD) turbulence, independently of any specific priors. The RWST coefficients encode moments of order up to four, have reduced variances, and quantify the couplings between scales. To show the efficiency and generality of this description, we applied it successfully to the following three kinds of processes that are a priori very different: fractional Brownian motions, MHD simulations, and Herschel observations of the dust thermal continuum in a molecular cloud. With fewer than 100 RWST coefficients when probing six scales and eight angles on 256 by 256 maps, we were able to perform quantitative comparisons, infer relevant physical properties, and produce realistic synthetic fields. © E. Allys et al. 2019."
"24335361400;57195348393;57211407731;57203026431;6603566335;35613452300;","Regional Superparameterization in a Global Circulation Model Using Large Eddy Simulations",2019,"10.1029/2018MS001600","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85073782396&doi=10.1029%2f2018MS001600&partnerID=40&md5=e33419907361d3abc4a19405067ef563","As a computationally attractive alternative for global large eddy simulations (LESs), we investigate the possibility of using comprehensive three-dimensional LESs as a superparameterization that can replace all traditional parameterizations of atmospheric processes that are currently used in global models. We present the technical design for a replacement of the parameterization for clouds, convection, and turbulence of the global atmospheric model of the European Centre for Medium-Range Weather Forecasts by the Dutch Atmospheric Large Eddy Simulation model. The model coupling consists of bidirectional data exchange between the global model and the high-resolution LES models embedded within the columns of the global model. Our setup allows for selective superparameterization, that is, for applying superparameterization in local regions selected by the user, while keeping the standard parameterization of the global model intact outside this region. Computationally, this setup can result in major geographic load imbalance, because of the large difference in computational load between superparameterized and nonsuperparameterized model columns. To resolve this issue, we use a modular design where the local and global models are kept as distinct model codes and organize the model coupling such that all the local models run in parallel, separate from the global model. First simulation results, employing this design, demonstrate the potential of our approach. © 2019. The Authors."
"55921094200;36615092600;6602273452;","Multi-Scale Geometric Summaries for Similarity-Based Sensor Fusion",2019,"10.1109/AERO.2019.8741399","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85068329360&doi=10.1109%2fAERO.2019.8741399&partnerID=40&md5=063a56177a052c30534c86b6bd36b3b2","In this work, we address fusion of heterogeneous sensor data using wavelet-based summaries of fused self-similarity information from each sensor. The technique we develop is quite general, does not require domain specific knowledge or physical models, and requires no training. Nonetheless, it can perform surprisingly well at the general task of differentiating classes of time-ordered behavior sequences which are sensed by more than one modality. As a demonstration of our capabilities in the audio to video context, we focus on the differentiation of speech sequences. Data from two or more modalities first are represented using self-similarity matrices(SSMs) corresponding to time-ordered point clouds in feature spaces of each of these data sources; we note that these feature spaces can be of entirely different scale and dimensionality. A fused similarity template is then derived from the modality-specific SSMs using a technique called similarity network fusion (SNF). We investigate pipelines using SNF as both an upstream (feature-level) and a downstream (ranking-level) fusion technique. Multiscale geometric features of this template are then extracted using a recently-developed technique called the scattering transform, and these features are then used to differentiate speech sequences. This method outperforms unsupervised techniques which operate directly on the raw data, and it also outperforms stovepiped methods which operate on SSMs separately derived from the distinct modalities. The benefits of this method become even more apparent as the simulated peak signal to noise ratio decreases. © 2019 IEEE."
"56041164300;57204465006;57069455200;55714061400;","Multiscale Sparse Features Embedded 4-Points Congruent Sets for Global Registration of TLS Point Clouds",2019,"10.1109/LGRS.2018.2872353","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85055713833&doi=10.1109%2fLGRS.2018.2872353&partnerID=40&md5=3492c03d4ec15a13983837537505d707","The 4-points congruent sets (4PCS) techniques have widely been used for global registration of point clouds in terrestrial laser scanning (TLS) applications. Nevertheless, due to many 4PCS methods adopt a downsampling strategy in the collection of correspondences; it is challenging to obtain a real congruent set of tuples in different point clouds with varying density. This letter embeds multiscale sparse features (MSSF) into 4PCS to enable efficient global registration of TLS clouds. Specifically, multiscale clusters are used to extract point features, among which a sparse coding is performed to obtain the representative MSSF. The obtained MSSF are then embedded into the 4PCS variants, taking both geometrical structure and representative feature similarity into account when performing a four-point congruent tuples matching. Moreover, a normal constraint is considered in the selection of noncoplanar four-point bases rather than coplanar ones in the source cloud. This configuration decreases the number of four-point bases and thus improves the processing efficiency and registration accuracy. The proposed method was applied to two experiments with TLS point clouds from building and hillslope scenarios, respectively. In addition, the proposed MSSF configuration was embedded in two 4PCS variants, and compared with the original methods for global registration. The comparison shows evident improvements in terms of the registration accuracy and efficiency if our embedment is used. © 2004-2012 IEEE."
"56073150900;57205096465;57194346898;57210601301;","Typhoon Cloud System Identification and Forecasting Using the Feng-Yun 4A/Advanced Geosynchronous Radiation Imager Based on an Improved Fuzzy Clustering and Optical Flow Method",2019,"10.1155/2019/5890794","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85071122219&doi=10.1155%2f2019%2f5890794&partnerID=40&md5=dad5ff615dcb67321b11ca7e4dab28be","This study adopted an improved fuzzy clustering and optical flow method for the multiscale identification and forecasting of a cloud system based on the cloud images from a 10.8-micron infrared channel of the Advanced Geosynchronous Radiation Imager. First, we used the locally constrained fuzzy c-means (FCM) clustering method to identify typhoon-dominant cloud systems. Second, we coupled the background field-constrained optical flow method with the semi-Lagrangian scheme to forecast typhoon-dominant cloud systems. The experimental results for Typhoon Maria showed that the improved FCM method was able to effectively identify changes in the cloud system while retaining its edge information through the effective removal of the offset field. The identified dominant cloud system was consistent with the precipitation field of the Global Precipitation Measurement mission. We optimized the semi-Lagrangian nonlinear extrapolation of the optical flow field by introducing background field information, thus improving the forecast accuracy of the optical flow field. Based on the assessment indicators of structural similarity, normalized mutual information, peak signal-to-noise ratio, relative standard deviation, and root mean square error, the forecast results demonstrated that the forecast effect of the background field-constrained optical flow method was better than that of the standard optical flow method. © 2019 Gen Wang et al."
"47061561600;57203058652;57203061817;7409240361;","A coarse-to-fine method for cloud detection in remote sensing images",2019,"10.1109/LGRS.2018.2866499","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053314896&doi=10.1109%2fLGRS.2018.2866499&partnerID=40&md5=83373e994e13d87a67a2c6f809c5e256","In this letter, a coarse-to-fine unsupervised method is proposed for cloud detection in remote sensing images. First, the color, texture, and statistical features of the remote sensing images are extracted with the color transform, dark channel estimation, Gabor filtering, and local statistical analysis methods. Then, an initial cloud detection map can be obtained by performing the support vector machines (SVM) on the stacked features, in which the SVM is trained with a set of samples automatically labeled by processing the dark channel of the original image with several thresholding and morphological operations. Finally, guided filtering is used to refine the boundaries in the initial detection map, which further improves the cloud detection accuracy. Experiments performed on several real remote sensing images demonstrate that the proposed method show better detection performances with respect to several recently proposed cloud detection methods in terms of both quantitative and visual comparisons. © 2004-2012 IEEE."
"6506835389;6603716679;6701650121;7003557662;","Optimizing UV Index determination from broadband irradiances",2018,"10.5194/gmd-11-1093-2018","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85044784314&doi=10.5194%2fgmd-11-1093-2018&partnerID=40&md5=6b0f4a1e81f143561e2998313a538105","A study was undertaken to improve upon the prognosticative capability of Environment and Climate Change Canada's (ECCC) UV Index forecast model. An aspect of that work, and the topic of this communication, was to investigate the use of the four UV broadband surface irradiance fields generated by ECCC's Global Environmental Multiscale (GEM) numerical prediction model to determine the UV Index. The basis of the investigation involves the creation of a suite of routines which employ high-spectral-resolution radiative transfer code developed to calculate UV Index fields from GEM forecasts. These routines employ a modified version of the Cloud-J v7.4 radiative transfer model, which integrates GEM output to produce high-spectral-resolution surface irradiance fields. The output generated using the high-resolution radiative transfer code served to verify and calibrate GEM broadband surface irradiances under clear-sky conditions and their use in providing the UV Index. A subsequent comparison of irradiances and UV Index under cloudy conditions was also performed. Linear correlation agreement of surface irradiances from the two models for each of the two higher UV bands covering 310.70-330.0 and 330.03-400.00nm is typically greater than 95% for clear-sky conditions with associated root-mean-square relative errors of 6.4 and 4.0%. However, underestimations of clear-sky GEM irradiances were found on the order of ∼30-50% for the 294.12-310.70nm band and by a factor of ∼30 for the 280.11-294.12nm band. This underestimation can be significant for UV Index determination but would not impact weather forecasting. Corresponding empirical adjustments were applied to the broadband irradiances now giving a correlation coefficient of unity. From these, a least-squares fitting was derived for the calculation of the UV Index. The resultant differences in UV indices from the high-spectral-resolution irradiances and the resultant GEM broadband irradiances are typically within 0.2-0.3 with a root-mean-square relative error in the scatter of ∼6.6% for clear-sky conditions. Similar results are reproduced under cloudy conditions with light to moderate clouds, with a relative error comparable to the clear-sky counterpart; under strong attenuation due to clouds, a substantial increase in the root-mean-square relative error of up to 35% is observed due to differing cloud radiative transfer models. © 2018 Copernicus GmbH. All rights reserved."
"7403282069;57195591631;8977001000;8882641700;16029674800;","Differences in the hydrological cycle and sensitivity between multiscale modeling frameworks with and without a higher-order turbulence closure",2017,"10.1002/2017MS000970","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029001695&doi=10.1002%2f2017MS000970&partnerID=40&md5=0cf3baeea27e8d4a29448b9952346a4f","Current conventional global climate models (GCMs) produce a weak increase in global-mean precipitation with anthropogenic warming in comparison with the lower tropospheric moisture increases. The motive of this study is to understand the differences in the hydrological sensitivity between two multiscale modeling frameworks (MMFs) that arise from the different treatments of turbulence and low clouds in order to aid to the understanding of the model spread among conventional GCMs. We compare the hydrological sensitivity and its energetic constraint from MMFs with (SPCAM-IPHOC) or without (SPCAM) an advanced higher-order turbulence closure. SPCAM-IPHOC simulates higher global hydrological sensitivity for the slow response but lower sensitivity for the fast response than SPCAM. Their differences are comparable to the spreads of conventional GCMs. The higher sensitivity in SPCAM-IPHOC is associated with the higher ratio of the changes in latent heating to those in net atmospheric radiative cooling, which is further related to a stronger decrease in the Bowen ratio with warming than in SPCAM. The higher sensitivity of cloud radiative cooling resulting from the lack of low clouds in SPCAM is another major factor in contributing to the lower precipitation sensitivity. The two MMFs differ greatly in the hydrological sensitivity over the tropical lands, where the simulated sensitivity of surface sensible heat fluxes to surface warming and CO2 increase in SPCAM-IPHOC is weaker than in SPCAM. The difference in divergences of dry static energy flux simulated by the two MMFs also contributes to the difference in land precipitation sensitivity between the two models. © 2017. The Authors."
"36987319800;","Simulation of orographic effects with a Quasi-3-D Multiscale Modeling Framework: Basic algorithm and preliminary results",2016,"10.1002/2016MS000783","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84999666052&doi=10.1002%2f2016MS000783&partnerID=40&md5=64d9f63516f0aff88240dbdec2e538f7","The global atmospheric models based on the Multi-scale Modeling Framework (MMF) are able to explicitly resolve subgrid-scale processes by using embedded 2-D Cloud-Resolving Models (CRMs). Up to now, however, those models do not include the orographic effects on the CRM grid scale. This study shows that the effects of CRM grid-scale orography can be simulated reasonably well by the Quasi-3-D MMF (Q3D MMF), which has been developed as a second-generation MMF. In the Q3D framework, the surface topography can be included in the CRM component by using a block representation of the mountains, so that no smoothing of the topographic height is necessary. To demonstrate the performance of such a model, the orographic effects over a steep mountain are simulated in an idealized experimental setup with each of the Q3D MMF and the full 3-D CRM. The latter is used as a benchmark. Comparison of the results shows that the Q3D MMF is able to reproduce the horizontal distribution of orographic precipitation and the flow changes around mountains as simulated by the 3-D CRM, even though the embedded CRMs of the Q3D MMF recognize only some aspects of the complex 3-D topography. It is also shown that the use of 3-D CRMs in the Q3D framework, rather than 2-D CRMs, has positive impacts on the simulation of wind fields but does not substantially change the simulated precipitation. © 2016. The Authors."
"57191094832;7003908632;","Importance of Chemical Composition of Ice Nuclei on the Formation of Arctic Ice Clouds",2016,"10.1007/s00024-016-1294-z","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84986587251&doi=10.1007%2fs00024-016-1294-z&partnerID=40&md5=5cbf54f6fea290d36d434694529176aa","Ice clouds play an important role in the Arctic weather and climate system but interactions between aerosols, clouds and radiation remain poorly understood. Consequently, it is essential to fully understand their properties and especially their formation process. Extensive measurements from ground-based sites and satellite remote sensing reveal the existence of two Types of Ice Clouds (TICs) in the Arctic during the polar night and early spring. TICs-1 are composed by non-precipitating small (radar-unseen) ice crystals of less than 30 μm in diameter. The second type, TICs-2, are detected by radar and are characterized by a low concentration of large precipitating ice crystals ice crystals (>30 μm). To explain these differences, we hypothesized that TIC-2 formation is linked to the acidification of aerosols, which inhibits the ice nucleating properties of ice nuclei (IN). As a result, the IN concentration is reduced in these regions, resulting to a lower concentration of larger ice crystals. Water vapor available for deposition being the same, these crystals reach a larger size. Current weather and climate models cannot simulate these different types of ice clouds. This problem is partly due to the parameterizations implemented for ice nucleation. Over the past 10 years, several parameterizations of homogeneous and heterogeneous ice nucleation on IN of different chemical compositions have been developed. These parameterizations are based on two approaches: stochastic (that is nucleation is a probabilistic process, which is time dependent) and singular (that is nucleation occurs at fixed conditions of temperature and humidity and time-independent). The best approach remains unclear. This research aims to better understand the formation process of Arctic TICs using recently developed ice nucleation parameterizations. For this purpose, we have implemented these ice nucleation parameterizations into the Limited Area version of the Global Multiscale Environmental Model (GEM-LAM) and use them to simulate ice clouds observed during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) in Alaska. Simulation results of the TICs-2 observed on April 15th and 25th (acidic cases) and TICs-1 observed on April 5th (non-acidic cases) are presented. Our results show that the stochastic approach based on the classical nucleation theory with the appropriate contact angle is better. Parameterizations of ice nucleation based on the singular approach tend to overestimate the ice crystal concentration in TICs-1 and TICs-2. The classical nucleation theory using the appropriate contact angle is the best approach to use to simulate the ice clouds investigated in this research. © 2016, Springer International Publishing."
"55653739600;7102309161;14067693600;22234191300;7202664004;","Hybrid fine scale climatology and microphysics of in-cloud icing: From 32km reanalysis to 5km mesoscale modeling",2015,"10.1016/j.atmosres.2014.11.006","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84949116482&doi=10.1016%2fj.atmosres.2014.11.006&partnerID=40&md5=7432bd79cac733b690663a3430624d6b","In-cloud icing can impose safety concerns and economic challenges for various industries. Icing climate representations proved beneficial for optimal designs and careful planning. The current study investigates in-cloud icing, its related cloud microphysics and introduces a 15-year time period climatology of icing events. The model was initially driven by reanalysis data from North American Regional Reanalysis and downscaled through a two-level nesting of 10. km and 5. km, using a limited-area version of the Global Environment Multiscale Model of the Canadian Meteorological Center. In addition, a hybrid approach is used to reduce time consuming calculations. The simulation realized exclusively on significant icing days, was combined with non-significant icing days as represented by data from NARR. A proof of concept is presented here for a 1000. km area around Gaspé during January for those 15. years.An increase in the number and intensity of icing events has been identified during the last 15years. From GEM-LAM simulations and within the atmospheric layer between 10m and 200m AGL, supercooled liquid water contents indicated a maximum of 0.4gm-3, and 50% of the values are less than 0.05gm-3. All values of median volume diameters (MVD) are approximately capped by 70μm and the typical values are around 15μm. Supercooled Large Droplets represent approximately 5%. The vertical profile of icing climatology demonstrates a steady duration of icing events until the level of 60m. The altitudes of 60m and 100m indicate substantial icing intensification toward higher elevations. GEM-LAM demonstrated a substantial improvement in the calculation of in-cloud icing, reducing significantly the challenge posed by complex terrains. © 2014 Elsevier B.V."
"55359866000;55342744700;6506696085;55145289900;56105220000;","Coupled atmospheric-ice load model for evaluation of wind plant power loss",2015,"10.1175/JAMC-D-14-0125.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84944072777&doi=10.1175%2fJAMC-D-14-0125.1&partnerID=40&md5=49df8d819187b623910d7cbe23ef00f2","Icing is a weather phenomenon that is typical of cold climates. It impacts human activities through ice accretion on tower structures, transmission lines, and the blades of wind turbines. Icing on turbine blades, in particular, results in wind turbine performance degradation and/or safety shutdowns. The objective of this study is to explore the feasibility of using a coupled atmospheric and ice load model to simulate icing start-up, duration, and amount while also quantitatively evaluating power loss in wind plants related to icing events and mechanisms. Eight of 27 icing episodes identified for a wind plant in the Gaspé region of Québec (Canada) during the period 2008-10 were simulated using a mesoscale model (the Global Environmental Multiscale Limited-Area Model, or GEM-LAM). The simulations were verified using near-surface temperature, relative humidity, and wind speed, all of which compared well to in situ observations. Simulated wind speed, precipitation, cloud liquid water content, and median volume diameter of the droplets were used to drive ice load models to simulate the total ice load on a cylindrical structure. The three ice load models accounted for freezing rain, wet snow, and in-cloud icing, respectively, and in all three cases a sink term was added to account for melting due to radiation. The start-up and duration of ice were well captured by the coupled model, and a positive correlation was found between icing episodes and wind power reduction. This study demonstrates the improvements of the icing forecasts by using three ice load models, and provides a framework for both qualitative and quantitative evaluation of icing impact on wind turbine operations. © 2015 American Meteorological Society."
"35573324500;15724736600;6602667330;7004233804;","Characterization of an unexpected snowfall event in iqaluit, nunavut, and surrounding area during the Storm Studies in the Arctic field project",2014,"10.1002/2013JD021176","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84901698368&doi=10.1002%2f2013JD021176&partnerID=40&md5=b0e52e7de4a85f6a146b4618dfcb59a2","Small accumulation precipitation events are critical for the high-latitude hydrological cycle. They contribute to more than 50% of total accumulation in the area and occur at a greater frequency than high-accumulation events. Despite their importance, the processes controlling them have not been investigated in sufficient detail. This study characterizes an unexpected high-latitude snowfall event at Iqaluit, Nunavut, and surrounding area during the Storm Studies in the Arctic field project. High-resolution data collected, from both ground based and airborne Doppler radar, along with upper air and surface observations, provided the basis for analysis of the conditions that led to the event and offer some insight as to why it was not well forecast by the Canadian operational model. Several factors worked in concert to produce this event. Low-level convection and upslope processes were important in cloud and precipitation generation over the orography upstream. When combined with additional lift from the passing of a weak trough, cloud and precipitation production were enhanced, allowing these features to penetrate over the terrain and resulted in precipitation at Iqaluit. Analysis of the global environmental multiscale limited area model (2.5 km resolution) suggests that upstream convection and upslope processes were affected by model errors. As a consequence, precipitation onset was delayed, and the total accumulation was 50% lower than the observations. Results indicate that the complexity of precipitation events in the region represents a significant challenge for predicting and modeling and understanding their role in the region’s hydrological cycle. © 2014. American Geophysical Union. All Rights Reserved."
"7003545639;7006127310;7003278104;7403128993;","Modeling monsoon intraseasonal variability from theory to operational forecasting",2011,"10.1175/2011BAMS3164.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-80053922831&doi=10.1175%2f2011BAMS3164.1&partnerID=40&md5=be692d5639d7c40a0199fa9f209253b2","The World Climate Research Program (WCRP) Climate Variability and Predictability (CLIVAR) Asian-Australian Monsoon Panel and the Year of Tropical Convection (YOTC) Madden-Julian Oscillation (MJO) Task Force organized a workshop on modeling monsoon intraseasonal variability (MISV) on June 15-18, 2010. It was held in Busan, South Korea, focusing on providing an up-to-date assessment of the current capability to predict and simulate MISV, and particularly the MJO. The workshop was organized into six sessions focusing on the current capability to model the MJO/MISV with GCM, convective parameterizations and development of process-oriented diagnostics, insights from theory and simplified models, and simulation diagnostics and forecast metrics for boreal summer MISV. The analysis to date for the global cloud system-resolving models (GCSRM) was effective in representing the MJO and the associated multiscale interactions involving aspects such as mesoscale interactions, convective momentum transport, and influences on other synoptic features."
"6506671742;6604063268;7004909806;","Simulation of satellite passive-microwave observations in rainy atmospheres at the meteorological service of Canada",2007,"10.1109/TGRS.2007.895335","https://www.scopus.com/inward/record.uri?eid=2-s2.0-34347240692&doi=10.1109%2fTGRS.2007.895335&partnerID=40&md5=7271b514344a92420ffaef07e7ccd3ef","In this paper, a research version of the Meteorological Service of Canada (MSC) Global Environmental Multiscale (GEM) mesoglobal weather forecasts model is evaluated by comparing the simulated Special Sensor Microwave/Imager brightness temperatures (Tbs) with the observed ones. Several comparisons based on two 15-day periods, one in winter and one in summer, have been done. Results are compared to those obtained for a study conducted on the European Centre for Medium-Range Weather Forecast (ECMWF) model. The overall performance of the GEM model is similar to that of the 2001 version of the ECMWF model. The model appears to simulate with realism the large-scale rainy systems but with frequent mislocations. Moreover, the model has a tendency to produce intense small-scale precipitating areas that are not observed. The occurrence frequency of cloud and rain is overestimated by the model. Finally, these results are encouraging enough to continue investigating the assimilation of Tbs in cloudy and rainy skies at MSC. © 2007 IEEE."
"7103293742;6506800680;6602616413;","Multi-sensor synthesis of the mesoscale structure of a cold-air comma cloud system",2002,"10.1017/S1350482702002025","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0042695578&doi=10.1017%2fS1350482702002025&partnerID=40&md5=03872bc32c5e29ae772d29330b410509","A multiscale study of a cold-air comma cloud that produced an area of heavy rain and locally severe weather has been undertaken by synthesizing data from a research microwave Doppler radar and VHF and UHF Doppler wind profilers, along with routinely available radar-network, satellite, in situ and mesoscale-model data. The rain area was generated in the exit region of an upper-level jet characterised by laminated velocity perturbations. Some of the perturbations were attributable to inertia-gravity wave activity. The rain area itself is shown to have been composed of a well-organised set of mesoscale rainbands each being due to a mixture of upright and slantwise convection. The existence of the multiple rainbands may have been related to the multi-layered atmospheric structure upwind. Each of the rainbands had cold-frontal and warm-frontal portions, so as to form a series of mini warm sectors stacked along the axis of the comma cloud at roughly 70 km intervals. The multiple rainbands were accompanied by multiple fingers of overrunning low-θw air from part of a dry intrusion originating from just below a major tropopause fold. The fold contained an intense potential-vorticity maximum which appeared to be the focus of the overall system. The operational mesoscale version of the Met. Office's Unified Model, with its 12 km grid, is shown to have resolved many but not all of the key features of the rainbands. It is suggested that further improvements in very-short-range forecasting of important local detail could be achieved by further increasing its resolution and assimilating more mesoscale observational data."
"7201424715;7004316179;7102594787;","Multiscale analysis of low-level vertical fluxes on day 261 of GATE.",1981,"10.1175/1520-0469(1981)038<1964:MAOLLV>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0019677681&doi=10.1175%2f1520-0469%281981%29038%3c1964%3aMAOLLV%3e2.0.CO%3b2&partnerID=40&md5=ed3baa9855c5796cbec3f6e3783bfa10","Data from a wide variety of measurement platforms are integrated to analyze a GATE cloud cluster and its environment. Lower tropospheric mass and moisture fluxes are computed on several scales using rawinsonde, aircraft, radar and satellite data from 18 Sept 1974. Lower tropospheric mass and moisture budget analyses are combined with GATE tethered-balloon measurements of cloud properties at cloud base to diagnose active cloud and turbulent fluxes in three areas of different scale ranging from 2.3-34.8 x 1010m2 (1.8-28.2 degrees latitude).-from Authors"
"57217081805;36849018600;","Surveying coastal cliffs using two UAV platforms (multirotor and fixed-wing) and three different approaches for the estimation of volumetric changes",2020,"10.1080/01431161.2020.1752950","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85083729535&doi=10.1080%2f01431161.2020.1752950&partnerID=40&md5=9da3dd3ce5c7e2d77f98f9a2a5ba5158","The increasing availability of highly detailed and accurate three-dimensional (3D) geospatial data are currently pushing the 3D change detection analysis towards a new 3D mapping frame. In this paper, medium-term changes (8 years) at a coastal rocky cliff are quantified using and comparing 2.5D and 3D methods to estimate the volume of rockfalls and three datasets: one Terrestrial Laser Scanner (TLS) acquired in 2010 and two coincident Unmanned Aerial Vehicles (UAV: multirotor and fixed-wing) datasets acquired in 2018. Advantages and limitations of these techniques, platforms and methods are discussed and the role of Ground Control Points (GCPs) distribution was analysed. Maps of 3D changes were produced by means of the Multiscale-Model-to-Model Cloud-Comparison algorithm (M3C2). The volume of the eroded-deposited material was estimated using two 2.5D and one 3D approaches: 1) rasterizing M3C2 distances using a conventional top-view perspective, 2) rasterizing the M3C2 distances rotated and orientated with the z vector normal and, 3) for the largest rockfalls, the volume was estimated using the Poisson Surface Reconstruction (PSR) algorithm (3D). The 3D models produced using both UAV platforms showed cm-level accuracies with Root Mean Square Error (RMSE) of 0.02 and 0.03 m for the multirotor and the fixed-wing, respectively, and faithfully represented cliff geometry. GCP configuration analysis showed that, at least, two stripes of GCPs evenly distributed at different heights are necessary, but three are recommended. The spatial pattern of change between the TLS and the two UAVs datasets was similar. The quantification of the volume of the eroded-accumulated material (using the M3C2 distances and the two UAV datasets) resulted in significant differences as the fixed-wing underestimated the values calculated using the multirotor dataset. The 2.5D strategies used to quantify the volume of change underestimated the eroded volume of the largest rockfalls (compared to the PSR 3D method), which provided the most accurate volume estimates. © 2020 Informa UK Limited, trading as Taylor & Francis Group."
"57202829757;57192525602;55995777500;14038511400;56066228900;","Cloud/snow recognition of satellite cloud images based on multiscale fusion attention network",2020,"10.1117/1.JRS.14.032609","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85083781328&doi=10.1117%2f1.JRS.14.032609&partnerID=40&md5=3f46aee17de68ef8018c9d395f72a722","Cloud/snow recognition technology has application significance in meteorological detection, aviation control, remote sensing disaster prevention, and mitigation. At present, the method of labeling cloud and snow area manually is time- and labor-consuming. Shallow learning methods not only have limited ability to extract cloud/snow semantic features but also have wake learning and expressive ability. These problems lead to the low accuracy of cloud/snow recognition in shallow learning methods. Deep learning methods extract cloud and snow semantic features layer-by-layer, and this feature extraction improves the accuracy of cloud/snow recognition. However, due to the complexity of cloud/snow texture features and the high similarity of cloud/snow spectral features, it is difficult to obtain satisfactory results for the classification of cloud and snow in plateau areas, by the existing deep learning models. In order to solve the above problems, a multiscale fusion attention network is proposed to recognize cloud and snow areas in plateau remote sensing images. In the proposed model, the main network is DenseNet25, which enhances the propagation and reuse of cloud/snow features in the network. A multiscale fusion is proposed to extract more complex cloud/snow texture and spectral features from spatial dimension. The high weight attention mechanism is introduced to obtain dynamic features based on input, and it is able to improve the discriminating ability of cloud and snow features. The experimental results demonstrate that the proposed model can extract and utilize cloud/snow feature information better than existing models and improve the accuracy and generalization of cloud/snow recognition. © 2020 Society of Photo-Optical Instrumentation Engineers (SPIE)."
"7403282069;57195591631;8977001000;7407116104;","Changes in clouds and atmospheric circulation associated with rapid adjustment induced by increased atmospheric CO2: a multiscale modeling framework study",2020,"10.1007/s00382-018-4401-2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85052296373&doi=10.1007%2fs00382-018-4401-2&partnerID=40&md5=e3955044695c1345abec24c43cafccb9","The radiative heating increase due to increased CO2 concentration is the primary source for the rapid adjustment of atmospheric circulation and clouds. In this study, we investigate the rapid adjustment resulting from an instantaneous doubling of CO2 and its physical mechanism using a multiscale modeling framework (MMF). The cloud-resolving model component of this MMF includes a sophisticated third-order turbulence closure and the MMF simulates realistic shallow and deep cloud climatology and boundary layer turbulence. Although the simulated cloud adjustment and its mechanism generally agree with earlier studies with conventional global climate models and another MMF with a lower-order turbulence closure, this MMF simulates an increase in the global-mean shortwave and net cloud radiative cooling and a negative cloud radiative effect change due to cloud adjustment. This result is related to the large increase in low-level clouds over the extratropical and subtropical oceans, resulting from reduced cloud-top entrainment implied from strengthened inversion. The downshift of planetary boundary layer and low-level clouds is generally weaker than that simulated by other models, which is due to reduction of shallow cumulus in the ascending and weak subsidence circulation regimes but to increase of stratocumulus in the strongest subsidence regime. Optically thicker stratocumulus compensates for reduced cooling by shallow cumulus. The reduced strength of all oceanic circulation regimes, which may be contributed by weakened energy transport resulting from water vapor and cloud CO2 masking effects, not only reduces optical depth of convective clouds but also shifts cloud coverage to lands where deep convection is enhanced. © 2018, The Author(s)."
"57212169855;57203719531;7202844175;","The implications of M3C2 projection diameter on 3D semi-automated rockfall extraction from sequential terrestrial laser scanning point clouds",2020,"10.3390/rs12111885","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85086463910&doi=10.3390%2frs12111885&partnerID=40&md5=1382a9bdf8752181f969ac47375e6ca5","Rockfall inventories are essential to quantify a rockfall activity and characterize the hazard. Terrestrial laser scanning and advancements in processing algorithms have resulted in three-dimensional (3D) semi-automatic extraction of rockfall events, permitting detailed observations of evolving rock masses. Currently, multiscale model-to-model cloud comparison (M3C2) is the most widely used distance computation method used in the geosciences to evaluate 3D changing features, considering the time-sequential spatial information contained in point clouds. M3C2 operates by computing distances using points that are captured within a projected search cylinder, which is locally oriented. In this work, we evaluated the effect of M3C2 projection diameter on the extraction of 3D rockfalls and the resulting implications on rockfall volume and shape. Six rockfall inventories were developed for a highly active rock slope, each utilizing a different projection diameter which ranged from two to ten times the point spacing. The results indicate that the greatest amount of change is extracted using an M3C2 projection diameter equal to, or slightly larger than, the point spacing, depending on the variation in point spacing. When the M3C2 projection diameter becomes larger than the changing area on the rock slope, the change cannot be identified and extracted. Inventory summaries and illustrations depict the influence of spatial averaging on the semi-automated rockfall extraction, and suggestions are made for selecting the optimal projection diameter. Recommendations are made to improve the methods used to semi-automatically extract rockfall from sequential point clouds. © 2020 by the authors."
"7004788617;7006414754;23491818900;","The physics of space weather/solar-terrestrial physics (STP): What we know now and what the current and future challenges are",2020,"10.5194/npg-27-75-2020","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85080110168&doi=10.5194%2fnpg-27-75-2020&partnerID=40&md5=4d8da1647933615bec8a06e92e695b1a","Major geomagnetic storms are caused by unusually intense solar wind southward magnetic fields that impinge upon the Earth's magnetosphere (Dungey, 1961). How can we predict the occurrence of future interplanetary events? Do we currently know enough of the underlying physics and do we have sufficient observations of solar wind phenomena that will impinge upon the Earth's magnetosphere? We view this as the most important challenge in space weather. We discuss the case for magnetic clouds (MCs), interplanetary sheaths upstream of interplanetary coronal mass ejections (ICMEs), corotating interaction regions (CIRs) and solar wind high-speed streams (HSSs). The sheath- and CIR-related magnetic storms will be difficult to predict and will require better knowledge of the slow solar wind and modeling to solve. For interplanetary space weather, there are challenges for understanding the fluences and spectra of solar energetic particles (SEPs). This will require better knowledge of interplanetary shock properties as they propagate and evolve going from the Sun to 1&thinsp;AU (and beyond), the upstream slow solar wind and energetic ""seed"" particles. Dayside aurora, triggering of nightside substorms, and formation of new radiation belts can all be caused by shock and interplanetary ram pressure impingements onto the Earth's magnetosphere. The acceleration and loss of relativistic magnetospheric ""killer"" electrons and prompt penetrating electric fields in terms of causing positive and negative ionospheric storms are reasonably well understood, but refinements are still needed. The forecasting of extreme events (extreme shocks, extreme solar energetic particle events, and extreme geomagnetic storms (Carrington events or greater)) are also discussed. Energetic particle precipitation into the atmosphere and ozone destruction are briefly discussed. For many of the studies, the Parker Solar Probe, Solar Orbiter, Magnetospheric Multiscale Mission (MMS), Arase, and SWARM data will be useful. © 2020 Copernicus GmbH. All rights reserved."
"22934904700;7201504886;8696069500;56032970700;7401945370;","A New Perspective for Future Precipitation Change from Intense Extratropical Cyclones",2019,"10.1029/2019GL084001","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85075207670&doi=10.1029%2f2019GL084001&partnerID=40&md5=bcd29bf221dbd5d1d1d9e50f231924d3","Extratropical cyclones, major contributors to precipitation in the midlatitudes, comprise mesoscale fronts and fine-scale convective storms. Intense oceanic cyclones pose natural hazards, making reliable projections of their changes with global warming of great interest. Here, we analyze the first ever global climate simulations to resolve such mesoscale dynamics of extratropical cyclones. The present-day structure, frequency, and precipitation of the oceanic extratropical cyclones compare well with reanalyses and new satellite datasets that resolve the multiscale cloud-precipitation system. Simulated precipitation from intense oceanic cyclones increases at a rate of 7%/K1, following Clausius-Clapeyron, with warming. The same scaling is apparent also in the interhemispheric contrast, suggesting that the latter could serve as a predictor of the former. Projected changes in precipitation from intense oceanic cyclones with warming may thus be testable using a reliable global observation network of precipitation in the present day. ©2019. The Authors."
"57128663100;56875080800;57200513988;56329651900;57203079982;7006524822;","Canopy and Terrain Interactions Affecting Snowpack Spatial Patterns in the Sierra Nevada of California",2019,"10.1029/2018WR023758","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85074830166&doi=10.1029%2f2018WR023758&partnerID=40&md5=190b87fb422209a72f4441d5f6fc5287","Airborne light detection and ranging is an emerging measurement tool for snowpack estimation, and data are now emerging to better assess multiscale snow depth patterns. We used airborne light detection and ranging measurements from four sites in the southern Sierra Nevada to determine how snow depth varies with canopy structure and the interactions between canopies and terrain. We processed the point clouds into snow depth rasters at 0.5×0.5-m2 resolution and performed statistical analysis on the processed snow depth data, terrain attributes, and vegetation attributes, including the individual tree bole locations, canopy crown area, and canopy height. We studied the snow depth at such a fine scale due in part to the spatial heterogeneity introduced by canopy interception and enhanced melting caused by tree trunks in forested areas. We found that the dominant direction of a tree well, the area around the tree bole that has shallower snowpack, is correlated with the local aspect of the terrain, and the gradient of the snow surface in a tree well is correlated with the tree's crown area. The regression-tree based XGBoost model was fitted with the topographic variables and canopy variables, and about 71% of snow depth variability can be explained by the model. ©2019. American Geophysical Union. All Rights Reserved."
"55658056352;57212172102;7402664815;7403349534;50861013700;56376781100;","An Accurate and Robust Region-Growing Algorithm for Plane Segmentation of TLS Point Clouds Using a Multiscale Tensor Voting Method",2019,"10.1109/JSTARS.2019.2936662","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076093152&doi=10.1109%2fJSTARS.2019.2936662&partnerID=40&md5=4c8c513f05bf4037b6be0298481ef630","The accuracy and robustness of plane segmentation using a region-growing algorithm remains an important and challenging topic for terrestrial laser scanning point clouds. The plane segmentation of a region-growing algorithm depends heavily on the seed point, as there are currently no universally valid criteria. This article proposes a multiscale tensor voting method (MSTVM) to determine the appropriate seed point for the region-growing algorithm. A comprehensive plane strength indicator calculated by the semivariogram model has been established to assess whether a certain point is suitably considered as a seed point or not. A point cloud containing 17, 881 points in a 400-m2 area was selected to validate the proposed algorithm. The results suggest that the scale range calculated by the semivariogram model can effectively mitigate the scale effect of the tensor voting method (TVM). The comprehensive plane strength of our proposed algorithm in seed point determination is shown to be more salient than the principal component analysis and the TVM. The findings further reveal that the utility of the MSTVM-based region-growing algorithm can achieve more accurate plane segmentation results and perform with better robustness in noisy point clouds. This allows our proposed method to be more widely applied to complex real situations. © 2008-2012 IEEE."
"56685153900;7003935694;7004142421;57210164209;57191409756;57192558453;7004881004;","HexaShrink, an exact scalable framework for hexahedral meshes with attributes and discontinuities: multiresolution rendering and storage of geoscience models",2019,"10.1007/s10596-019-9816-2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85069665155&doi=10.1007%2fs10596-019-9816-2&partnerID=40&md5=31841f3dc0d23cc53d8e340dd46becab","With huge data acquisition progresses realized in the past decades and acquisition systems now able to produce high resolution grids and point clouds, the digitization of physical terrains becomes increasingly more precise. Such extreme quantities of generated and modeled data greatly impact computational performances on many levels of high-performance computing (HPC): storage media, memory requirements, transfer capability, and finally simulation interactivity, necessary to exploit this instance of big data. Efficient representations and storage are thus becoming “enabling technologies” in HPC experimental and simulation science. We propose HexaShrink, an original decomposition scheme for structured hexahedral volume meshes. The latter are used for instance in biomedical engineering, materials science, or geosciences. HexaShrink provides a comprehensive framework allowing efficient mesh visualization and storage. Its exactly reversible multiresolution decomposition yields a hierarchy of meshes of increasing levels of details, in terms of either geometry, continuous or categorical properties of cells. Starting with an overview of volume meshes compression techniques, our contribution blends coherently different multiresolution wavelet schemes in different dimensions. It results in a global framework preserving discontinuities (faults) across scales, implemented as a fully reversible upscaling at different resolutions. Experimental results are provided on meshes of varying size and complexity. They emphasize the consistency of the proposed representation, in terms of visualization, attribute downsampling and distribution at different resolutions. Finally, HexaShrink yields gains in storage space when combined to lossless compression techniques. © 2019, The Author(s)."
"57204744715;35752249500;55945667800;6603308366;","Effect of Meteorological Variability on Fine Particulate Matter Simulations Over the Contiguous United States",2019,"10.1029/2018JD029637","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85066492355&doi=10.1029%2f2018JD029637&partnerID=40&md5=f86cc972bc797cc87e13d54fe516dfe3","This study quantifies the impact of meteorological variability on the Community Multiscale Air Quality (CMAQ) model-simulated particulate matter of aerodynamic diameter 2.5 μm or smaller (particulate matter 2.5 [PM2.5]) over the contiguous United States (CONUS). The meteorological variability is represented using the Short-Range Ensemble Forecast (SREF) produced operationally by the National Oceanic and Atmospheric Administration. A hierarchical cluster analysis technique is applied to down-select a subset of the SREF members that objectively accounts for the overall meteorological forecast variability of SREF. Three SREF members are selected to drive off-line CMAQ simulations during January, April, July, and October 2016. Changes in emissions, vertical diffusion, and aerosol processes due to meteorological variability dominate changes in aerosol mass concentrations over 55-73% of the domain except in July when dry deposition dominates emissions and aerosol processes. Weather Research and Forecasting-Advanced Research WRF (WRF-ARW) simulations reproduced the variability of surface temperature very well but overestimated the 10-m wind speed, precipitation, and at some sites the planetary boundary layer height. Averaged over CONUS, CMAQ simulations driven by all three meteorological configurations capture the observed daytime low and nighttime high PM2.5 mass concentrations but underestimated the observed concentrations likely due to faster advection and higher wet deposition in the model. PM2.5 levels across the three simulations agreed well during daytime but showed larger variability during nighttime due to dominance of aerosol, clouds, and advection processes in nighttime. The meteorology-induced variability in PM2.5 is estimated to be 0.08–24 μg/m3 over the CONUS with larger variability over the eastern United States. ©2019. American Geophysical Union. All Rights Reserved."
"36987319800;6603218374;7202208382;","Implementation of the Vector Vorticity Dynamical Core on Cubed Sphere for Use in the Quasi-3-D Multiscale Modeling Framework",2019,"10.1029/2018MS001517","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85062373617&doi=10.1029%2f2018MS001517&partnerID=40&md5=1177b89e025f6b2b6a869dbcfdde5a69","The dynamical core that predicts the three-dimensional vorticity rather than the momentum, which is called Vector-Vorticity Model (VVM), is implemented on a cubed sphere. Its horizontal coordinate system is not restricted to orthogonal, while the vertical coordinate is orthogonal to the horizontal surface. Accordingly, all the governing equations of the VVM, which are originally developed with Cartesian coordinates, are rewritten in terms of general curvilinear coordinates. The local coordinates on each cube surface are constructed with the gnomonic equiangular projection. Using global channel domains, the VVM on the cubed sphere has been evaluated by (1) advecting a passive tracer with a bell-shaped initial perturbation along an east-west latitude circle and along a north-south meridional circle and (2) simulating the evolution of barotropic and baroclinic instabilities. The simulated results with the cubed-sphere grids are compared to analytic solutions or those with the regular longitude-latitude grids. The convergence with increasing spatial resolution is also quantified using standard error norms. The comparison shows that the solutions with the cubed-sphere grids are quite reasonable for both linear and nonlinear problems when high resolutions are used. With coarse resolution, degeneracy appears in the solutions of the nonlinear problems such as spurious wave growth; however, it is effectively reduced with increased resolution. Based on the encouraging results in this study, we intend to use this model as the cloud-resolving component in a global Quasi-Three-Dimensional Multiscale Modeling Framework. ©2019. The Authors."
"6507973681;55553587400;57200115162;6602505244;6602489251;","Topographic base maps from remote sensing data for engineering geomorphological modelling: An application on coastal mediterranean landscape",2019,"10.3390/geosciences9120500","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85075788817&doi=10.3390%2fgeosciences9120500&partnerID=40&md5=f1d91896e1509f79fbe8fb0da72e56c2","Coastal landscapes are one of the most changeable areas of the earth's surface. Given this spatial complexity and temporal variability, the construction of reference maps useful for geo-engineering is a challenge. In order to improve the performance of geomorphic models, reliable multiscale and multi-temporal base maps and Digital Elevation Models (DEM) are needed. The work presented in this paper addresses this issue using an inter-geo-disciplinary approach to optimize the processing of multisource and multi-temporal data and DEMs by using field surveys, conceptual model, and analytical computation on a test area. The data acquired with two surveying techniques were analyzed and compared: Aerial Laser Scanning (ALS) and photogrammetry from stereo pairs of High-Resolution Satellite Images (HRSI). To assess the reliability of the DEMs produced from point clouds, the residuals between the point cloud and the interpolated filtered surface were identified and analyzed statistically. In addition to the contour maps, some feature maps such as slope, planar, and profile curvature maps were produced and analyzed. The frequency distribution of the slope and curvature values were compared with the diffusion, advection, and stream power model, revealing a good agreement with the past and present geomorphic processes acting on the different parts of the study area. Moreover, the integrated geomatics–geomorphic analysis of the outliers’ map showed a good correspondence (more than 75%) between the identified outliers and some specific geomorphological features, such as micro-landforms, which are significant for erosive and gravity-driven mechanisms. The different distribution of the above singularities by different data sources allowed us to attribute their spatial model to the temporal variation of the topography and, consequently, to the geomorphic changes, rather than to the different accuracy. For monitoring purposes and risk mitigation activities, the methodology adopted seems to meet the requirements to make a digital mapping of the coast analyzed, characterized by a rapid evolution of the surface, and can be extended to other stretches of coast with similar characteristics. © 2019 by the authors. Licensee MDPI, Basel, Switzerland."
"57204195754;10339673300;","Comparison of filtering algorithms used for dtm production from airborne lidar data: A case study in Bergama, Turkey [Primerjava algoritmov za filtriranje za izdelavo dmr iz lidarskih podatkov: študijski primer Bergama, Turčija]",2019,"10.15292/geodetski-vestnik.2019.03.395-414","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85073520145&doi=10.15292%2fgeodetski-vestnik.2019.03.395-414&partnerID=40&md5=5b46dbe19da6f148cff18353b3b0d45f","A light detection and ranging (lidar) system is one of the most important technologies used for generating digital terrain models (DTMs). The point cloud data obtained by these systems consist of data gathered from ground and nonground features. To create a DTM with high resolution and accuracy, ground and nonground data must be separated. Numerous filtering algorithms have been developed for this purpose. The aim of this study was testing the filtering performance of six different filtering algorithms in four different test areas with different land cover were selected that had topographical features and characteristics. The algorithms were adaptive triangulated irregular network (ATIN), elevation threshold with an expand window (ETEW), maximum local slope (MLS), progressive morphology (PM), iterative polynomial fitting (IPF), and multiscale curvature classification (MCC) algorithms. In the results, all the filters performed well on a smooth surface and produced more errors in complex urban areas and rough terrain with dense vegetation. The IPF filtering algorithm generated the best results for the first three test areas (smooth landscape, urban areas and agricultural areas), while ETEW performed best in the fourth test area (steep areas with dense vegetation and infrastructure). © 2019, Zvava Geodetov Slovenije. All rights reserved."
"57210823235;57209325574;57211903687;","An analysis of ground-point classifiers for terrestrial LiDAR",2019,"10.3390/rs11161915","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85071596714&doi=10.3390%2frs11161915&partnerID=40&md5=63f8137411accaee5751110429ee5826","Previous literature has compared the performance of existing ground point classification (GPC) techniques on airborne LiDAR (ALS) data (LiDAR-light detection and ranging); however, their performance when applied to terrestrial LiDAR (TLS) data has not yet been addressed. This research tested the classification accuracy of five openly-available GPC algorithms on seven TLS datasets: Zhang et al.'s inverted cloth simulation (CSF), Kraus and Pfeiffer's hierarchical weighted robust interpolation classifier (HWRI), Axelsson's progressive TIN densification filter (TIN), Evans and Hudak's multiscale curvature classification (MCC), and Vosselman's modified slope-based filter (MSBF). Classification performance was analyzed using the kappa index of agreement (KIA) and rasterized spatial distribution of classification accuracy datasets generated through comparisons with manually classified reference datasets. The results identified a decrease in classification accuracy for the CSF and HWRI classification of low vegetation, for the HWRI and MCC classifications of variably sloped terrain, for the HWRI and TIN classifications of low outlier points, and for the TIN and MSBF classifications of off-terrain (OT) points without any ground points beneath. Additionally, the results show that while no single algorithm was suitable for use on all datasets containing varying terrain characteristics and OT object types, in general, a mathematical-morphology/slope-based method outperformed other methods, reporting a kappa score of 0.902. © 2019 by the authors."
"56027749100;57207913692;57204792189;7005854169;","Simulated dispersion of the gas released by the SpaceX Falcon9 rocket explosion",2018,"10.2514/1.A34145","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85056642464&doi=10.2514%2f1.A34145&partnerID=40&md5=f78a4e8e578190af3cc210a627a02a09","This Paper provides a qualitative analysis of the contaminant dispersion caused by the SpaceX Falcon 9 rocket accident at Cape Canaveral Air Force Station on 1 September 2016. To achieve this, the Model for Simulating Rocket Exhaust Dispersion and its modeling system were applied to simulate the dispersion of the contaminants emitted during the explosion of the Falcon 9 rocket. This modeling system is a modern tool for risk management and environmental analysis for the evaluation of normal and aborted rocket launch events, being also suitable for the assessment of explosion cases. It deals with the representation of the source term (formation, rising, expansion, and stabilization of the exhaust cloud), the simulation of the short-range dispersion (in the scale from minutestoacouple of hours), and the long-range and chemical transport modeling by integrating with the Community Multiscale Air Quality model and reading meteorological input data from the Weather Research and Forecast model. The results showed that the modeling system captured satisfactorily the phenomenon inside the planetary boundary layer. Copyright © 2018 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved."
"57190880220;7006861646;6603000896;7102019758;","Stochastic generation of precipitation fraction at high resolution with a multiscale constraint from satellite observations",2018,"10.1002/qj.3314","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85055977305&doi=10.1002%2fqj.3314&partnerID=40&md5=d239c43c2052747eb98dccfe69345e3e","In this work, we propose a method to generate an ensemble of equiprobable fields of rain occurrence at high resolution (1°/16 and 30 min) using a satellite observational constraint. Satellite observations are used to constrain the spatio-temporal variations of the precipitation fraction at various scales. Spatio-temporal averages at scales coarser than 1° and 8 h are deterministically derived from the satellite observations. At finer scales, variations are partially stochastically generated by perturbation of wavelet coefficients obtained through a three-dimensional discrete Haar wavelet orthogonal decomposition. The proposed method can be viewed either as stochastic weather generation or as stochastic downscaling with a multiscale observational constraint. The observational constraint used here is a high-resolution precipitation index derived from infrared cloud top temperature. As a proof of concept, the method is used here to generate a 300-member annual ensemble covering a 12,000 km2 area in Burkina Faso in West Africa, with a parametrization derived from ground radar observations. The stochastically generated fields aim at reproducing the multiscale statistical properties of the true precipitation field (as observed by a ground radar). The ensemble mean is an optimal – in terms of mean squared error – estimation of the true precipitation fraction, with the uncertainty quantified by the ensemble dispersion. © 2018 Royal Meteorological Society"
"56587020100;7006256622;","Long-Lived Mesoscale Convective Systems of Superparameterized CAM and the Response of CAM",2018,"10.1029/2018MS001339","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053461778&doi=10.1029%2f2018MS001339&partnerID=40&md5=a87407a35a3c885145a317a552fa1b12","Mesoscale organized convection is generally misrepresented in the large-scale convective parameterizations used in contemporary climate models. This impacts extreme weather events (e.g., Madden-Jullian Oscillation) and the general circulation driven by the significant amount of latent heat released from mesoscale organized convection. Studies show that the missing processes could be partially recovered by embedding a 2-D cloud-resolving model in each general circulation model columns, that is, superparameterization. To enable analysis of mesoscale convective systems (MCSs) in the multiscale modeling framework, we apply a detection and hierarchical clustering algorithm on the 3-hourly 2-D cloud-resolving model embedded in the superparameterized Community Atmosphere Model (SPCAM) 5.2. We then examine the fields of a long-lived and large MCS cluster at the central Pacific. The MCS cluster shows a squall line-like circulation throughout the life cycle in SPCAM. We simultaneously obtain the 3-hourly CAM parameterized convection outputs based on the time step-wise perfect initial conditions given by SPCAM. This allows pure model physics comparison without introducing initial condition errors. The results show that CAM has a systematically biased stratiform cooling and moistening response below 3 km to the given SPCAM deep convection favoring conditions. We show that this bias is mainly due to the CAM's stratiform microphysics scheme. The mesoscale organization in SPCAM thus provides a baseline for improvements of convective parameterization of CAM. ©2018. The Authors."
"16305516000;56192121900;57201487640;","Harmonic extension on the point cloud",2018,"10.1137/16M1098747","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85045054370&doi=10.1137%2f16M1098747&partnerID=40&md5=4f8df65d9daaff21e416814eb142c4b7","In this paper, we consider the harmonic extension problem, which is widely used in many applications of machine learning. We formulate the harmonic extension as solving a Laplace–Beltrami equation with Dirichlet boundary condition. We use the point integral method (PIM) proposed in [Z. Li, Z. Shi, and J. Sun, Commun. Comput. Phys., 22 (2017), pp. 228–258; Z. Shi and J. Sun, Res. Math. Sci., to appear; Z. Li and Z. Shi, Multiscale Model. Simul., 14 (2016), pp. 874–905] to solve the Laplace–Beltrami equation. The basic idea of the PIM method is to approximate the Laplace equation using an integral equation, which is easy to discretize from points. Based on the integral equation, we found that the traditional graph Laplacian method (GLM) fails to approximate the harmonic functions near the boundary. One important application of the harmonic extension in machine learning is semisupervised learning. We run a popular semisupervised learning algorithm by Zhu, Ghahramani, and Lafferty [Machine Learning, Proceedings of the Twentieth International Conference (ICML 2003), 2003, Washington, DC, 2003, ARAI Press, Menlo Park, CA pp. 912–919] over a couple of well-known datasets and compare the performance of the aforementioned approaches. Our experiments show the PIM performs the best. We also apply PIM to an image recovery problem and show it outperforms GLM. Finally, on the model problem of the Laplace–Beltrami equation with Dirichlet boundary, we prove the convergence of the point integral method. © 2018 Society for Industrial and Applied Mathematics."
"57201177267;7101931045;","The South American monsoon system",2017,"10.1142/9789813200913_0003","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85020316002&doi=10.1142%2f9789813200913_0003&partnerID=40&md5=6fe59b6fba3558ef9e9a3665d98e9fa9","The multiscale nature of the South American Monsoon System is presented here in a review of the interannual to decadal variability, intraseasonal variability and regional and mesoscale features of the clouds systems associated with the break and active phases. Although the lack of long records in the Amazon and surrounding areas limits multidecadal analyses of the monsoon, associations of monsoon features with the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation have been found. There is evidence that El Niño/La Niña modulate the South Atlantic Convergence Zone and extreme daily rainfall events in the region. The onset/demise of the SAMS is variable throughout the region and associated to different features of convective activity, and the convective/ stratiform partition. Aerosols emitted by biomass burning have been shown to act as Could Condensation Nuclei whereby they may affect clouds although during the premonsoon phase not much sensitivity has been found to variations in aerosol concentration. During the wet season, however, aerosol concentration appears as a possible cause to explain convective intensity. Predictability of onset, amplitude, duration and demise of SAMS have shown increased skill through empirical relationships between bimonthly average precipitation and modes of interannual variability of upper level winds in South America. © 2017 World Scientific Publishing Co. Pte. Ltd."
"55714647400;26632168400;57206503877;","Evaluation of high-level clouds in cloud resolving model simulations with ARM and KWAJEX observations",2015,"10.1002/2015MS000478","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84959563110&doi=10.1002%2f2015MS000478&partnerID=40&md5=a4b089c3c4242db2a057cd4ae4280c02","In this study, we evaluate high-level clouds in a cloud resolving model during two convective cases, ARM9707 and KWAJEX. The simulated joint histograms of cloud occurrence and radar reflectivity compare well with cloud radar and satellite observations when using a two-moment microphysics scheme. However, simulations performed with a single moment microphysical scheme exhibit low biases of approximately 20 dB. During convective events, two-moment microphysical overestimate the amount of high-level cloud and one-moment microphysics precipitate too readily and underestimate the amount and height of high-level cloud. For ARM9707, persistent large positive biases in high-level cloud are found, which are not sensitive to changes in ice particle fall velocity and ice nuclei number concentration in the two-moment microphysics. These biases are caused by biases in large-scale forcing and maintained by the periodic lateral boundary conditions. The combined effects include significant biases in high-level cloud amount, radiation, and high sensitivity of cloud amount to nudging time scale in both convective cases. The high sensitivity of high-level cloud amount to the thermodynamic nudging time scale suggests that thermodynamic nudging can be a powerful ""tuning"" parameter for the simulated cloud and radiation but should be applied with caution. The role of the periodic lateral boundary conditions in reinforcing the biases in cloud and radiation suggests that reducing the uncertainty in the large-scale forcing in high levels is important for similar convective cases and has far reaching implications for simulating high-level clouds in super-parameterized global climate models such as the multiscale modeling framework. © 2015 The Authors."
"57015826100;23991212200;","The effect of large-scale model time step and multiscale coupling frequency on cloud climatology, vertical structure, and rainfall extremes in a superparameterized GCM",2015,"10.1002/2015MS000493","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84959536194&doi=10.1002%2f2015MS000493&partnerID=40&md5=d315f1dcaa4ecf6aea4d3ab402f7eed7","The effect of global climate model (GCM) time step-which also controls how frequently global and embedded cloud resolving scales are coupled-is examined in the Superparameterized Community Atmosphere Model ver 3.0. Systematic bias reductions of time-mean shortwave cloud forcing (-10 W/m2) and longwave cloud forcing (-5 W/m2) occur as scale coupling frequency increases, but with systematically increasing rainfall variance and extremes throughout the tropics. An overarching change in the vertical structure of deep tropical convection, favoring more bottom-heavy deep convection as a global model time step is reduced may help orchestrate these responses. The weak temperature gradient approximation is more faithfully satisfied when a high scale coupling frequency (a short global model time step) is used. These findings are distinct from the global model time step sensitivities of conventionally parameterized GCMs and have implications for understanding emergent behaviors of multiscale deep convective organization in superparameterized GCMs. The results may also be useful for helping to tune them. © 2015. The Authors."
"56083341000;7004091561;24338002400;","Partitioning of HNO3, H2O2 and SO2 to cloud ice: Simulations with CMAQ",2014,"10.1016/j.atmosenv.2013.12.041","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84896829969&doi=10.1016%2fj.atmosenv.2013.12.041&partnerID=40&md5=0fec1d6f85cf2d72e5f362f564acd3b0","In the upper troposphere, gas phase species can partition to cloud ice, undergo chemical reaction and contribute to particle mass aloft, affecting chemical cycling in the atmosphere. This manuscript describes the first implementation of gas-to-cloud ice partitioning of three inorganic gases, HNO3, SO2 and H2O2, along with subsequent SO2 oxidation in the Community Multiscale Air Quality (CMAQ) chemical transport model. Four simulations are performed with CMAQv4.7.1 that include lightning production of NO for August 12th-25th of 2005 to investigate the impacts of ice chemistry on CMAQ-predicted gas phase mixing ratios and particle mass concentrations of associated species. Considerable episodic decreases, greater than 25%, in gas phase HNO3 are noted at pressures of 200-600mb, with the largest changes at 300-400mb. Effects are also induced on other gases in the nitrogen budget. NOx and HONO mixing ratios decrease up to 20%, but changes are generally less than 10%. Nitrate aerosol mass concentrations increase up to 0.15μgm-3 for the highest model layers (100mb). We find that phase changes in nitrogen species induced by ice partitioning are sensitive to CMAQ predictions of the aerosol phase accumulation mode ammonium to sulfate ratios [NH4+]:[SO42-]. Predicted O3 concentrations do not change (&lt;1%). No changes in H2O2, SO2, or sulfate aerosol concentrations are observed. © 2014 Elsevier Ltd."
"55660994800;57196489468;56520921400;","Global dust simulations in the multiscale modeling framework",2013,"10.1029/2012MS000150","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876698441&doi=10.1029%2f2012MS000150&partnerID=40&md5=2710004d335439faffa5226288ad77fd","This study investigates the role of subgrid vertical transport in global simulations of soil-dust aerosols. The evolution and long-range transport of aerosols are strongly affected by vertical transport. In conventional global models, convective and turbulent transport is highly parameterized. This study applies the superparameterization (SP) framework in which a cloud-resolving model (CRM) is embedded in each grid cell of a global model to replace these parametric treatments with explicit simulation of subgrid processes at the cloud-system scale. We apply the implementation of the SP framework in the National Center for Atmospheric Research community atmospheric model (CAM) denoted by SPCAM for dust simulations. We focus on the effects of subgrid transport on dust simulations; thus, the sources and sinks of dust are calculated in the large-scale CAM grids, and the vertical transport of dust is computed in the CRM. We simulate present-day distributions of soil-dust aerosols using CAM and SPCAM operated in chemical transport mode with large-scale meteorological fields prescribed using the same meteorological reanalysis. Therefore, the differences of dust fields between two models caused by explicit versus parameterized treatments of convective transport are examined. Comparison of dust profiles shows that SPCAM predicts less dust in the low to mid troposphere but relatively higher concentration in the upper troposphere. The larger dust mass in upper troposphere in SPCAM may be related to the dust implementation approach in this study, in which the larger resolved updrafts in CRM for deep convection transport more dust aloft but are not accounted by the removal processes in the CRM grid scale. A slightly higher mobilization flux of less than 5% on an average is shown in SPCAM when compared with CAM. Similar patterns of elevated dry deposition are also produced with increases larger than 100% in some areas. For wet deposition, on average CAM is ∼31% higher than SPCAM. The average burden of dust in the simulated year for SPCAM and CAM is 14.8 and 19.7 Tg, respectively. The time-scale analysis shows the predicted dust lifetimes in SPCAM are shorter than CAM by approximately 1 day. The differences between CAM and SPCAM demonstrate that process-oriented treatments of convection can significantly affect the distributions, sources, and sinks of global soil-dust simulations. © 2012. American Geophysical Union. All Rights Reserved."
"54788308700;7003908632;12764954600;","An evaluation of arctic cloud and radiation processes simulated by the limited-area version of the Global Multiscale Environmental Model (GEM-LAM)",2011,"10.1080/07055900.2011.604266","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84055211873&doi=10.1080%2f07055900.2011.604266&partnerID=40&md5=95fb035616e7e45d950c4a1ad887834d","Cloud and radiation processes simulated by the limited area version of the Global Environmental Multiscale Model (GEM-LAM) are evaluated for the period September 1997 to October 1998 over the western Arctic Ocean. This period coincides with the Surface Heat Budget of the Arctic Ocean (SHEBA) field experiment. Surface downwelling solar and terrestrial radiation, surface albedo, vertically integrated water vapour, liquid water path, precipitation, cloud cover and cloud radiative forcing simulated by GEM-LAM are evaluated against the SHEBA observation dataset. GEM-LAM simulates the annual cycle of the downwelling shortwave (SWD) and longwave (LWD) radiation at the surface reasonably well, as well as precipitable water at monthly and daily time scales. Cloud fraction at daily and monthly time scales is not captured well by the model. During winter, GEM-LAM produces a large negative bias for the vertically integrated liquid water path and a positive bias for cloud fraction. As a result, cloud radiative forcing at the surface and LWD radiation are well reproduced but for the wrong reasons because these two biases have an opposing effect on their magnitudes. During summer, the model underestimates the surface albedo, thus resulting in a substantial overestimation of the cloud radiative forcing at the surface. Precipitation is underestimated during winter and overestimated during summer and spring. The sensitivity of the results to the effective radius of ice crystals and the parameterization of cloud phase is also discussed."
"7004830620;","Cloud bands induced by isolated mountains",1999,"10.1256/smsqj.55918","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033402786&doi=10.1256%2fsmsqj.55918&partnerID=40&md5=6ff84cff88d0ac9a6f0cc1c8d1027f63","The wave equation is solved analytically to obtain the solutions of diverging types of trapped waves, caused by an isolated hill, at the top of a convective boundary layer with an overlying stable layer above. Wind veering in the upper stable layer favours the wave trains to be to the left of the mean wind direction. The elevated lifting latent heat may make the crest line of the diverging wave a diabatic heating band, if the water vapour supply is sufficient. Analytical solution is also used to analyse the effects of a heating band, which makes a small angle with the mean wind direction. The trapped components of the induced waves may spread horizontally and excite wave trains running parallel to the original heating band. The untrapped waves hold an in-phase relation with the heating. The resultants of trapped and untrapped waves possess multiscale structure and properties similar to those of cloud streets. These analyses may provide an explanation for the formation and propagation of cloud streets."
"57218584938;57218584242;57201031500;57191432058;","UAV photogrammetry accuracy assessment for corridor mapping based on the number and distribution of ground control points",2020,"10.3390/RS12152447","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089675973&doi=10.3390%2fRS12152447&partnerID=40&md5=c8a0900e38251ec8ed845ba4704fc64d","Unmanned aerial vehicle (UAV) photogrammetry has recently emerged as a popular solution to obtain certain products necessary in linear projects, such as orthoimages or digital surface models. This is mainly due to its ability to provide these topographic products in a fast and economical way. In order to guarantee a certain degree of accuracy, it is important to know how many ground control points (GCPs) are necessary and how to distribute them across the study site. The purpose of this work consists of determining the number of GCPs and how to distribute them in a way that yields higher accuracy for a corridor-shaped study area. To do so, several photogrammetric projects have been carried out in which the number of GCPs used in the bundle adjustment and their distribution vary. The different projects were assessed taking into account two different parameters: the root mean square error (RMSE) and the Multiscale Model to Model Cloud Comparison (M3C2). From the different configurations tested, the projects using 9 and 11 GCPs (4.3 and 5.2 GCPs km-1, respectively) distributed alternatively on both sides of the road in an offset or zigzagging pattern, with a pair of GCPs at each end of the road, yielded optimal results regarding fieldwork cost, compared to projects using similar or more GCPs placed according to other distributions. © 2020 by the authors."
"57194201247;7004479957;6701346974;","The Role of Multiscale Interaction in Tropical Cyclogenesis and Its Predictability in Near-Global Aquaplanet Cloud-Resolving Simulations",2020,"10.1175/JAS-D-20-0021.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089404752&doi=10.1175%2fJAS-D-20-0021.1&partnerID=40&md5=f71f85b7141a1a8b29b61c59c2265531","Tropical cyclogenesis (TCG) is a multiscale process that involves interactions between large-scale circulation and small-scale convection. A near-global aquaplanet cloud-resolving model (NGAqua) with 4-km horizontal grid spacing that produces tropical cyclones (TCs) is used to investigate TCG and its predictability. This study analyzes an ensemble of three 20-day NGAqua simulations, with initial white-noise perturbations of low-level humidity. TCs develop spontaneously from the northern edge of the intertropical convergence zone (ITCZ), where large-scale flows and tropical convection provide necessary conditions for barotropic instability. Zonal bands of positive low-level absolute vorticity organize into cyclonic vortices, some of which develop into TCs. A new algorithm is developed to track the cyclonic vortices. A vortex-following framework analysis of the low-level vorticity budget shows that vertical stretching of absolute vorticity due to convective heating contributes positively to the vorticity spinup of the TCs. A case study and composite analyses suggest that sufficient humidity is key for convective development. TCG in these three NGAqua simulations undergoes the same series of interactions. The locations of cyclonic vortices are broadly predetermined by planetary-scale circulation and humidity patterns associated with ITCZ breakdown, which are predictable up to 10 days. Whether and when the cyclonic vortices become TCs depend on the somewhat more random feedback between convection and vorticity. © 2020 American Meteorological Society."
"57191925668;55468705200;57199238005;57196026721;57211081884;56198793300;","ALS Point Cloud Classification with Small Training Data Set Based on Transfer Learning",2020,"10.1109/LGRS.2019.2947608","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85082297372&doi=10.1109%2fLGRS.2019.2947608&partnerID=40&md5=0bfb204016c3962f4cdca52a0646b0ee","Point cloud classification of airborne light detection and ranging (LiDAR) data is essential to extract geoinformation. Although deep learning provides a new approach for classification, the time-consuming training process and data dependence prevent its widespread application to point clouds. To solve these problems and leverage the potential of high-performing neural networks, we propose an airborne LiDAR point cloud classification method based on transfer learning. A strategy to generate feature images considering the point cloud spatial distribution is first introduced for applying traditional convolutional neural networks to point clouds. Then, transfer learning is used to extract multiscale and multiview deep features. A simple neural network classifier is designed to reduce dimensionality, fuse and learn high-level features, and postprocessing considering contextual information further improves the classification accuracy. We verified the performance of the proposed method through experiments on two airborne LiDAR data sets with different characteristics and containing eight classes. The results demonstrate that the proposed method can achieve a satisfactory classification accuracy with relatively short training time and less training samples than if using conventional methods. © 2020 IEEE."
"35182162900;57204071088;57217103837;57217729362;57204076620;","An effective cloud detection method for Gaofen-5 images via deep learning",2020,"10.3390/rs12132106","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85087542810&doi=10.3390%2frs12132106&partnerID=40&md5=a77a291a0551b6de8fa618ecce214450","Recent developments in hyperspectral satellites have dramatically promoted the wide application of large-scale quantitative remote sensing. As an essential part of preprocessing, cloud detection is of great significance for subsequent quantitative analysis. For Gaofen-5 (GF-5) data producers, the daily cloud detection of hundreds of scenes is a challenging task. Traditional cloud detection methods cannot meet the strict demands of large-scale data production, especially for GF-5 satellites, which have massive data volumes. Deep learning technology, however, is able to perform cloud detection efficiently for massive repositories of satellite data and can even dramatically speed up processing by utilizing thumbnails. Inspired by the outstanding learning capability of convolutional neural networks (CNNs) for feature extraction, we propose a new dualbranch CNN architecture for cloud segmentation for GF-5 preview RGB images, termed a multiscale fusion gated network (MFGNet), which introduces pyramid pooling attention and spatial attention to extract both shallow and deep information. In addition, a new gated multilevel feature fusion module is also employed to fuse features at different depths and scales to generate pixelwise cloud segmentation results. The proposed model is extensively trained on hundreds of globally distributed GF-5 satellite images and compared with current mainstream CNN-based detection networks. The experimental results indicate that our proposed method has a higher F1 score (0.94) and fewer parameters (7.83 M) than the compared methods. © 2020 by the authors. Licensee MDPI, Basel, Switzerland."
"57210193249;55716092000;55713076400;","Effects of convection-SST interactions on the South China Sea summer monsoon onset in a multiscale modeling framework model",2020,"10.3319/TAO.2020.02.25.01","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85084386605&doi=10.3319%2fTAO.2020.02.25.01&partnerID=40&md5=7428fb733a3a6032b8de4108a2470aa4","The present study explores the effects of convection-SST interactions on the onset of the South China Sea Summer Monsoon simulated by the superparameterized Community Atmosphere Model (SPCAM). The SPCAM is a global multi-scale modeling framework that embeds a 2-D cloud-resolving model in each grid column to replace the conventional convective parameterization. Two experiments are performed: CTRL uses prescribed sea surface temperature climatology, and CPL is coupled to a slab ocean model (SOM). The bias of excessive seasonal mean precipitation over Asia during boreal summer in CTRL is reduced in CPL. In the South China Sea, the seasonal evolution of precipitation and 850 hPa winds is more realistic in the coupled simulation. During the pre-onset stage, the mean pattern of synoptic flow and precipitation, as well as the land-ocean diurnal cycle contrast is also improved in CPL. The coupling to SOM does not change the sensitivity of precipitation to column moisture in the SPCAM. The improvements in CPL can be partly attributed to the lower SST in response to air-sea interactions, and also partly to the suppression of heavy precipitation under high SST regime likely associated with a different atmospheric meridional circulation. Our current results demonstrated that the SPCAM coupled with SOM could be a potential tool to study the interactions among convection, SST, and large-scale atmospheric circulation from seasonal to sub-seasonal time scales. © 2020 Chinese Geoscience Union. All rights reserved."
"57116791700;57213553013;57208605963;57215065893;","Extraction of snow cover from high-resolution remote sensing imagery using deep learning on a small dataset",2020,"10.1080/2150704X.2019.1686548","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85074297447&doi=10.1080%2f2150704X.2019.1686548&partnerID=40&md5=036962cdfc21cd3698d13f3e6404f51a","Snow cover is of great significance for many applications. However, automatic extraction of snow cover from high spatial resolution remote sensing (HSRRS) imagery remains challenging, owing to its multiscale characteristics, similarities to clouds, and occlusion by the shadows of mountains and clouds. Deep convolutional neural networks for semantic segmentation are the most popular approach to automatic map generation, but they require huge computing time and resources, as well as a large dataset of pixel-wise annotated HSRRS images, which precludes the application of many superior models. In this study, these limitations are overcome by using a sequence of transfer learning steps. The method starts with a modified aligned ‘Xception’ model pre-trained for object classification on ImageNet. Subsequently, a ‘DeepLab version three plus’ (DeepLabv3+) model is trained using a large dataset of Landsat images and corresponding snow cover products. Finally, a second transfer learning step is employed to fine-tune the model on the small dataset of GaoFen-2, the highest resolution HSRRS satellite in China. Experiments demonstrate the feasibility and effectiveness of this framework for automatic snow cover extraction. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group."
"7102890144;57205497429;6603565405;35737202600;6701835010;7202208382;57210430928;55597313700;57210424390;","Surface-Atmosphere Coupling Scale, the Fate of Water, and Ecophysiological Function in a Brazilian Forest",2019,"10.1029/2019MS001650","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85070716775&doi=10.1029%2f2019MS001650&partnerID=40&md5=93be88b4750b7a141f565b6445a041ae","Tropical South America plays a central role in global climate. Bowen ratio teleconnects to circulation and precipitation processes far afield, and the global CO2 growth rate is strongly influenced by carbon cycle processes in South America. However, quantification of basin-wide seasonality of flux partitioning between latent and sensible heat, the response to anomalies around climatic norms, and understanding of the processes and mechanisms that control the carbon cycle remains elusive. Here, we investigate simulated surface-atmosphere interaction at a single site in Brazil, using models with different representations of precipitation and cloud processes, as well as differences in scale of coupling between the surface and atmosphere. We find that the model with parameterized clouds/precipitation has a tendency toward unrealistic perpetual light precipitation, while models with explicit treatment of clouds produce more intense and less frequent rain. Models that couple the surface to the atmosphere on the scale of kilometers, as opposed to tens or hundreds of kilometers, produce even more realistic distributions of rainfall. Rainfall intensity has direct consequences for the “fate of water,” or the pathway that a hydrometeor follows once it interacts with the surface. We find that the model with explicit treatment of cloud processes, coupled to the surface at small scales, is the most realistic when compared to observations. These results have implications for simulations of global climate, as the use of models with explicit (as opposed to parameterized) cloud representations becomes more widespread. ©2019. The Authors."
"7404743997;57202678174;35262206000;57218493610;","Automatic Registration Method for TLS LiDAR Data and Image-Based Reconstructed Data",2019,"10.1109/LGRS.2018.2875178","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85055683910&doi=10.1109%2fLGRS.2018.2875178&partnerID=40&md5=27eb5aeabbbbb72450d72cf2ccbfac71","Point clouds registration is an important research topic in the field of data fusion from camera and light detection and ranging (LiDAR). In this letter, a new registration method, fast multiscale registration (FMSR), takes the scale factor into account and is proposed for the registration of two point clouds obtained from camera and LiDAR. An adaptive-scale keypoint quality algorithm was used to detect and match keypoints, which were input to the coarse registration process to improve the coarse registration accuracy. A new heuristic criterion was also proposed for fine registration, which avoids falling into the local minima. Furthermore, to increase efficiency of fine registration, the k-nearest neighbors algorithm was selected to directly search the optimal matching from the raw point clouds without triangulating point clouds into mesh. The FMSR method is highly precise, insensitive to outliers, and relatively efficient. Experimental results showed that the root-mean-square error of the registration was approximately 0.2 m when the size of the object was about 20.3 m × 7.85 m × 26.56 m, the total number of matched points was 12 789, and the execution time was approximately 2.1 s, indicating that the proposed method resulted in improved accuracy and efficiency of registration. © 2004-2012 IEEE."
"36642806800;6701718244;55184906800;","Towards the complete census of molecular hydrogen in a simulated disc galaxy",2019,"10.1093/mnras/stz048","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85091440819&doi=10.1093%2fmnras%2fstz048&partnerID=40&md5=f43d3d87f58c9fb1f9cd5e0f0a5e1c81","We present a multiscale analysis of molecular hydrogen in aMilkyWay-like simulated galaxy. Our census covers the gas content of the entire disc, to radial profiles and the Kennicutt-Schmidt relation, to a study of its molecular clouds, and finally down to a cell-by-cell analysis of the gas phases. A significant fraction of the H2 gas is in low-density regions mixed with atomic hydrogen and would therefore be difficult to observe. We use the molecular addition to RAMSES-RT, an adaptive mesh refinement grid code with the hydrodynamics coupled to moment-based radiative transfer. Three resolutions of the same galaxy detail the effects it has on H2 formation, with grid cells sized 97, 24, and 6.1 pc. Only the highest resolution yields gas densities high enough to host significant H2 fractions, and resolution is therefore key to simulating H2. Our H2 content is not completely converged but we find general agreement with available observations. Apart our pieces of galactic analysis are disparate, but assembled, they provide a cohesive portrait of H2 in the interstellar medium. H2 chemistry on the atomic scale is sufficient to generate its dynamics throughout an entire galaxy. © 2020 Lippincott Williams and Wilkins. All rights reserved."
"55606974300;7003666669;56162305900;15755995900;7006270084;55405340400;8511991900;56384704800;55688930000;7006643234;55802246600;","Development and Evaluation of an Explicit Treatment of Aerosol Processes at Cloud Scale Within a Multi-Scale Modeling Framework (MMF)",2018,"10.1029/2018MS001287","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050830348&doi=10.1029%2f2018MS001287&partnerID=40&md5=a2ef4bc1dd31afdb5538e4543e101b1c","Modeling the aerosol lifecycle in traditional global climate models (GCM) is challenging for a variety of reasons, not the least of which is the coarse grid. The multiscale modeling framework (MMF), in which a cloud resolving model replaces conventional parameterizations of cloud processes within each GCM grid column, provides a promising framework to address this challenge. Here we develop a new version of MMF that for the first time treats aerosol processes at cloud scale to improve the aerosol-cloud interaction representation in the model. We demonstrate that the model with the explicit aerosol treatments shows significant improvements of many aspects of the simulated aerosols compared to the previous version of MMF with aerosols parameterized at the GCM grid scale. The explicit aerosol treatments produce a significant increase of the column burdens of black carbon (BC), primary organic aerosol, and sulfate by up to 40% in many remote regions, a decrease of the sea-salt aerosol burdens by 40% in remote regions. These differences are caused by the differences in aerosol convective transport and wet removal between these two models. The new model also shows reduced bias of BC surface concentration in North America and BC vertical profiles in the high latitudes. However, the biased-high BC concentrations in the upper troposphere over the remote Pacific regions remain, requiring further improvements on other process representations (e.g., secondary activation neglected in the model). ©2018. The Authors."
"57207102262;55683853900;7403347013;7202206591;57207776795;","Multiscale adaptive reconstruction of missing information for remotely sensed data using sparse representation",2018,"10.1080/2150704X.2018.1439198","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048730523&doi=10.1080%2f2150704X.2018.1439198&partnerID=40&md5=54a533e082e6311729836753fe30105b","Due to the influence of sensor malfunction and poor atmospheric condition, missing information is inevitable in optical remotely sensed (RS) data, which limits the availability of RS data. To tackle the inverse problem of missing information recovery, a multiscale adaptive patch reconstruction method was proposed in this letter. Multiscale dictionaries were learned from different sizes of exemplars in the known image region, which were later utilized to infer missing information patch-by-patch via sparse representation. Structure sparsity was incorporated to encourage the filling-in of missing patch on image structures and determine the patch size for further inpainting. Neighboring information was employed to restrain the appearance of the estimated patch, to yield semantically consistent inpainting result. In view of these ideas, we formulate the optimization model of adaptive patch inpainting and reconstruct missing information through a multiscale scheme. Experiments are performed on cloud removal, gaps filling and quantitative product reconstruction, which demonstrate that our method can well preserve spatially continuous structures and consistent textures without artifacts. © 2018 2018 Informa UK Limited, trading as Taylor & Francis Group."
"57195219129;7101959253;55087038900;","The Diurnal Cycle of Clouds and Precipitation at the ARM SGP Site: An Atmospheric State-Based Analysis and Error Decomposition of a Multiscale Modeling Framework Simulation",2017,"10.1002/2017JD027542","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85040734102&doi=10.1002%2f2017JD027542&partnerID=40&md5=798e1bab261e2dae06b63c37a1a02030","Long-term reflectivity data collected by a millimeter cloud radar at the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site are used to examine the diurnal cycle of clouds and precipitation and are compared with the diurnal cycle simulated by a Multiscale Modeling Framework (MMF) climate model. The study uses a set of atmospheric states that were created specifically for the SGP and for the purpose of investigating under what synoptic conditions models compare well with observations on a statistical basis (rather than using case studies or seasonal or longer time scale averaging). Differences in the annual mean diurnal cycle between observations and the MMF are decomposed into differences due to the relative frequency of states, the daily mean vertical profile of hydrometeor occurrence, and the (normalized) diurnal variation of hydrometeors in each state. Here the hydrometeors are classified as cloud or precipitation based solely on the reflectivity observed by a millimeter radar or generated by a radar simulator. The results show that the MMF does not capture the diurnal variation of low clouds well in any of the states but does a reasonable job capturing the diurnal variations of high clouds and precipitation in some states. In particular, the diurnal variations in states that occur during summer are reasonably captured by the MMF, while the diurnal variations in states that occur during the transition seasons (spring and fall) are not well captured. Overall, the errors in the annual composite are due primarily to errors in the daily mean of hydrometeor occurrence (rather than diurnal variations), but errors in the state frequency (that is, the distribution of weather states in the model) also play a significant role. ©2017. The Authors."
"36238621200;7006790230;7005464924;35403793700;57205916396;35220447800;23037191800;35608582600;25924805300;56238859600;57151800100;7401474720;7102145940;56675377000;55532647900;7404044150;55531949600;7003485288;7005309616;7403458984;","Timeline analysis and wavelet multiscale analysis of the AKARI All-Sky Survey at 90 μm",2008,"10.1111/j.1365-2966.2008.13292.x","https://www.scopus.com/inward/record.uri?eid=2-s2.0-45149092661&doi=10.1111%2fj.1365-2966.2008.13292.x&partnerID=40&md5=989cfcf5817209f1ee92aa40aebebc32","We present a careful analysis of the point-source detection limit of the AKARI All-Sky Survey in the WIDE-S 90-μm band near the North Ecliptic Pole (NEP). Timeline analysis is used to detect IRAS (Infrared Astronomy Satellite) sources and then a conversion factor is derived to transform the peak timeline signal to the interpolated 90-μm flux of a source. Combined with a robust noise measurement, the point-source flux detection limit at signal-to-noise ratio (S/N) > 5 for a single detector row is 1.1 ± 0.1 Jy which corresponds to a point-source detection limit of the survey of ∼0.4 Jy. Wavelet transform offers a multiscale representation of the Time Series Data (tsd). We calculate the continuous wavelet transform of the tsd and then search for significant wavelet coefficients considered as potential source detections. To discriminate real sources from spurious or moving objects, only sources with confirmation are selected. In our multiscale analysis, IRAS sources selected above 4σ can be identified as the only real sources at the Point Source Scales. We also investigate the correlation between the non-IRAS sources detected in timeline analysis and cirrus emission using wavelet transform and contour plots of wavelet power spectrum. It is shown that the non-IRAS sources are most likely to be caused by excessive noise over a large range of spatial scales rather than real extended structures such as cirrus clouds. © 2008 The Authors."
"24344412700;57213319039;24342663000;7006787386;36646428700;","Model simulations of extreme orographic precipitation in the Sierra Nevada during the new year's holiday flood of 2005-06",2007,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-80053171306&partnerID=40&md5=31c640a8e18c4dae80ee0e655d7c7806","Forecasting precipitation In mountainous regions is a very demanding and arduous task. Some examples of devastating flooding events in mountainous areas include the Big Thompson Flood of 1976 in the Rocky Mountains (Maddox 1978) and the Piedmont flood event of 1994 in the Alps (Buzzi et al. 1998). The flooding events in the Sierra Nevada during 1997 and 2005 had a major impact on the Truckee River Valley including the Reno metropolitan area, however not much has been documented with either case. Both flooding events In Reno involved the passage of upper-level cold fronts that enabled ageostrophic and diabatic adjustments to create processes that led to flooding rains. It Is the juxtaposition of the cold front aloft, tropical air stream from the South Pacific and complex terrain that led to the extreme lee side liquid precipitation accumulation to a significant elevation. This paper focuses on the 2005 event. A verification of the simulation of the 2005 case study employing the Operational Multiscale Environment model with Grid Adaptivity (OMEGA) (e.g., Bacon et al. 2000) was performed. What makes OMEGAa novel approach for modeling research and forecasting Is that it employs an unstructured grid that can be used to adapt to certain features like clouds and terrain, therefore enhancing the local resolution of key orographic forcing features. The OMEGA adaptive grid simulations were performed with static grid adaptivity to 1 km resolution over the Sierra Nevada. These simulations were then validated against asynoptlc and synoptic observations including Doppler and surface rainfall observations. The goal for this research is to 1) explore whether or not an unstructured, static, adaptive grid will produce accurate simulations of an extreme lee side rainfall event and 2) to aid forecasters in understanding the precursor physical and dynamical processes which cause such an event."
"6701754792;55880561900;6506416572;6701409929;","Multiscale analysis of FASTEX secondary cyclogenesis from airborne Doppler radar",1999,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032660475&partnerID=40&md5=0646f2c5dc85bdcad169ace35783768e","The international project FASTEX (Fronts and Atlantic Storm-Track Experiment) has been designed to account for secondary cyclogenesis. The field phase of FASTEX took place in January-February 1997 in the North Atlantic Ocean. Taking advantage of the FASTEX dataset, an accurate description of the 3-D kinematic and thermodynamic fields at mesoscale and convective-scale in both the clear-air and precipitating areas of the cyclones is obtained."
"7003506951;","Spatial variability in radar backscatter from the ocean surface imaged by satellite-based SAR caused by multiscale atmospheric turbulence",1998,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-0031626272&partnerID=40&md5=4a1d9fbe8f53814825b16e8d502f06b1","Synthetic aperture radar (SAR) streak patterns and cloud streets are compared, and the cloud street patterns' consistency with atmospheric roll vortices is studied. A direct and definitive confirmation that multiscale SAR streaks can be caused by multiscale atmospheric roll vortices is presented."
"57213508524;54415303600;57217197857;57193684854;57217196065;56123335600;","Analysis of aerosol optical properties in a Lanzhou suburb of China",2020,"10.1016/j.atmosres.2020.105098","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85086705265&doi=10.1016%2fj.atmosres.2020.105098&partnerID=40&md5=c96df63646252bff427eba1f56c6cbe0","In order to accurately identify feature layer and monitor the spatial and temporal distribution of pollutants, the inversion method of lidar measurement based on multiscale algorithm is proposed in this paper. The detection of clouds, aerosols and dust layers using a modified retrieval algorithm for a dual-wavelength lidar is presented at the Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL). Moreover, the aerosol optical depth calculated from the Klett-Fernald algorithm obviously excludes the influence of clouds. Two cases were presented to demonstrate that the modified algorithm can capture low-clouds and dust layers well. The aerosol optical properties including aerosol optical depth (AOD), effective radius, depolarization ratio and black carbon aerosol mass concentration are analysed in terms of their monthly and seasonal variations. It is shown that the maximum of AOD, depolarization ratio and effective radius were found in spring (0.42 ± 0.35, 0.17 ± 0.1, 0.63 ± 0.24 μm) and the minimums were found in summer and autumn. The black carbon aerosol mass concentration varies significantly throughout year, with the maximum value in winter (2.35 ± 1.56 μg m−3) and a secondary maximum in autumn (1.93 ± 1.28 μg m−3), a minimum (1.03 ± 0.76 μg m−3) in spring. The vertical distribution of extinction coefficient has a peak near 1 km (0.1 km−1). The depolarization ratio vertically distributes at approximately 0.15. In general, pollution is more serious in spring and winter at SACOL, the former pollutants are coarse-mode non-spherical dust particles which originate from the Taklimakan Desert and the Gobi Desert, and the latter are fine mode spherical black carbon aerosols and coarse-mode non-spherical dust aerosols which are the results of both local combustion and long-distance transport. The dust particles existed high-altitude transport in spring and winter at SACOL. © 2020 Elsevier B.V."
"57188639624;6602298788;6506509805;10042680800;7005967755;7005276494;6701348241;57189225001;6602499262;57203570957;57197772612;6604029574;8418698400;6602447168;35766085300;15765851100;57188688483;","Evaluating Sentinel-5P TROPOMI tropospheric NO2 column densities with airborne and Pandora spectrometers near New York City and Long Island Sound",2020,"10.5194/amt-13-6113-2020","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85096494432&doi=10.5194%2famt-13-6113-2020&partnerID=40&md5=e941a2fbb4023fc6090e0ad1ac261139","Airborne and ground-based Pandora spectrometer NOspan classCombining double low line""inline-formula""2/span column measurements were collected during the 2018 Long Island Sound Tropospheric Ozone Study (LISTOS) in the New York City/Long Island Sound region, which coincided with early observations from the Sentinel-5P TROPOspheric Monitoring Instrument (TROPOMI) instrument. Both airborne- and ground-based measurements are used to evaluate the TROPOMI NOspan classCombining double low line""inline-formula""2/span Tropospheric Vertical Column (TrVC) product v1.2 in this region, which has high spatial and temporal heterogeneity in NOspan classCombining double low line""inline-formula""2/span. First, airborne and Pandora TrVCs are compared to evaluate the uncertainty of the airborne TrVC and establish the spatial representativeness of the Pandora observations. The 171 coincidences between Pandora and airborne TrVCs are found to be highly correlated (span classCombining double low line""inline-formula""ir/i2Combining double low line/spanthinsp;0.92 and slope of 1.03), with the largest individual differences being associated with high temporal and/or spatial variability. These reference measurements (Pandora and airborne) are complementary with respect to temporal coverage and spatial representativity. Pandora spectrometers can provide continuous long-term measurements but may lack areal representativity when operated in direct-sun mode. Airborne spectrometers are typically only deployed for short periods of time, but their observations are more spatially representative of the satellite measurements with the added capability of retrieving at subpixel resolutions of 250thinsp;mthinsp;span classCombining double low line""inline-formula""×/spanthinsp;250thinsp;m over the entire TROPOMI pixels they overfly. Thus, airborne data are more correlated with TROPOMI measurements (span classCombining double low line""inline-formula""ir/i2Combining double low line0.96/span) than Pandora measurements are with TROPOMI (span classCombining double low line""inline-formula""ir/i2Combining double low line0.84/span). The largest outliers between TROPOMI and the reference measurements appear to stem from too spatially coarse a priori surface reflectivity (0.5span classCombining double low line""inline-formula""g /span) over bright urban scenes. In this work, this results during cloud-free scenes that, at times, are affected by errors in the TROPOMI cloud pressure retrieval impacting the calculation of tropospheric air mass factors. This factor causes a high bias in TROPOMI TrVCs of 4thinsp;%-11thinsp;%. Excluding these cloud-impacted points, TROPOMI has an overall low bias of 19thinsp;%-33thinsp;% during the LISTOS timeframe of June-September 2018. Part of this low bias is caused by coarse a priori profile input from the TM5-MP model; replacing thesespan idCombining double low line""page6114""/ profiles with those from a 12thinsp;km North American Model-Community Multiscale Air Quality (NAMCMAQ) analysis results in a 12thinsp;%-14thinsp;% increase in the TrVCs. Even with this improvement, the TROPOMI-NAMCMAQ TrVCs have a 7thinsp;%-19thinsp;% low bias, indicating needed improvement in a priori assumptions in the air mass factor calculation. Future work should explore additional impacts of a priori inputs to further assess the remaining low biases in TROPOMI using these datasets./. © 2020 Royal Society of Chemistry. All rights reserved."
"57194465323;7404736154;37101940700;7006026220;8385769600;55499410800;","Sensitivity analysis of the surface ozone and fine particulate matter to meteorological parameters in China",2020,"10.5194/acp-20-13455-2020","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85096181720&doi=10.5194%2facp-20-13455-2020&partnerID=40&md5=32a20e0afdd1795163cf872d3420ce48","Meteorological conditions play important roles in the formation of ozone (O3) and fine particulate matter (PM2:5). China has been suffering from serious regional air pollution problems, characterized by high concentrations of surface O3 and PM2:5. In this study, the Community Multiscale Air Quality (CMAQ) model was used to quantify the sensitivity of surface O3 and PM2:5 to key meteorological parameters in different regions of China. Six meteorological parameters were perturbed to create different meteorological conditions, including temperature (T ), wind speed (WS), absolute humidity (AH), planetary boundary layer height (PBLH), cloud liquid water content (CLW) and precipitation (PCP). Air quality simulations under the perturbed meteorological conditions were conducted in China in January and July of 2013. The changes in O3 and PM2:5 concentrations due to individual meteorological parameters were then quantified. T has a great influence on the daily maximum 8 h average O3 (O3-8 h) concentrations, which leads to O3-8 h increases by 1.7 in January in Chongqing and 1.1 ppbK1 in July in Beijing. WS, AH, and PBLH have a smaller but notable influence on O3-8 h with maximum change rates of 0.3 ppb%1, 0:15 ppb%1, and 0.14 ppb%1, respectively. T , WS, AH, and PBLH have important effects on PM2:5 formation of both in January and July. In general, PM2:5 sensitivities are negative to T , WS, and PBLH and positive to AH in most regions of China. The sensitivities in January are much larger than in July. PM2:5 sensitivity to T , WS, PBLH, and AH in January can be up to 5 ugm3 K1, 3 ugm3 %1, 1 ugm3 %1, and C0:6 ugm3 %1, respectively, and in July it can be up to 2 ugm3 K1, 0:4 ugm3 %1, 0:14 ugm3 %1, and C0:3 ugm3 %1, respectively. Other meteorological factors (CLW and PCP) have negligible effects on O3-8 h (less than 0.01 ppb%1) and PM2:5 (less than 0.01 ugm3 %1). The results suggest that surface O3 and PM2:5 concentrations can change significantly due to changes in meteorological parameters, and it is necessary to consider these effects when developing emission control strategies in different regions of China. © 2020 EDP Sciences. All rights reserved."
"55232897900;23991212200;8882641700;7004479957;","The Impact of Resolving Subkilometer Processes on Aerosol-Cloud Interactions of Low-Level Clouds in Global Model Simulations",2020,"10.1029/2020MS002274","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85096471375&doi=10.1029%2f2020MS002274&partnerID=40&md5=c814ccd6215804bca809afb29c47a194","Subkilometer processes are critical to the physics of aerosol-cloud interaction (ACI) but have been dependent on parameterizations in global model simulations. We thus report the strength of ACI in the Ultra-Parameterized Community Atmosphere Model (UPCAM), a multiscale climate model that uses coarse exterior resolution to embed explicit cloud-resolving models with enough resolution (250 m horizontal, 20 m vertical) to quasi-resolve subkilometer eddies. To investigate the impact on ACIs, UPCAM's simulations are compared to a coarser multiscale model with 4 km horizontal resolution. UPCAM produces cloud droplet number concentrations (Nd) and cloud liquid water path (LWP) values that are higher than the coarser model but equally plausible compared to observations. Our analysis focuses on the Northern Hemisphere (20–50°N) oceans, where historical aerosol increases have been largest. We find similarities in the overall radiative forcing from ACIs in the two models, but this belies fundamental underlying differences. The radiative forcing from increases in LWP is weaker in UPCAM, whereas the forcing from increases in Nd is larger. Surprisingly, the weaker LWP increase is not due to a weaker increase in LWP in raining clouds, but a combination of weaker increase in LWP in nonraining clouds and a smaller fraction of raining clouds in UPCAM. The implication is that as global modeling moves toward finer than storm-resolving grids, nuanced model validation of ACI statistics conditioned on the existence of precipitation and good observational constraints on the baseline probability of precipitation will become key for tighter constraints and better conceptual understanding. ©2020. The Authors."
"55462884000;6701562113;56612517400;57194470383;16246205000;57207176515;","Studying scale dependency of aerosol-cloud interactions using multiscale cloud formulations",2020,"10.1175/JAS-D-19-0203.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85095862297&doi=10.1175%2fJAS-D-19-0203.1&partnerID=40&md5=ba41a5432f39e1c98140bf3016fd3fb5","The Weather Research and Forecasting Model with Aerosol-Cloud Interactions (WRF-ACI) configuration is used to investigate the scale dependency of aerosol-cloud interactions (ACI) across the ""gray zone""scales for grid-scale and subgrid-scale clouds. The impacts of ACI on weather are examined across regions in the eastern and western United States at 36, 12, 4, and 1 km grid spacing for short-term periods during the summer of 2006. ACI impacts are determined by comparing simulations with current climatological aerosol levels to simulations with aerosol levels reduced by 90%. The aerosol-cloud lifetime effect is found to be the dominant process leading to suppressed precipitation in regions of the eastern United States, while regions in the western United States experience offsetting impacts on precipitation from the cloud lifetime effect and other effects that enhance precipitation. Generally, the cloud lifetime effect weakens with decreasing grid spacing due to a decrease in relative importance of autoconversion compared to accretion. Subgrid-scale ACI are dominant at 36 km, while grid-scale ACI are dominant at 4 and 1 km. At 12 km grid spacing, grid-scale and subgridscale ACI processes are comparable in magnitude and spatial coverage, but random perturbations in grid-scale ACI impacts make the overall grid-scale ACI impact appear muted. This competing behavior of grid- and subgrid-scale clouds complicate the understanding of ACI at 12 km within the current WRF modeling framework. The work implies including subgrid-scale cloud microphysics and ice/mixed-phase-cloud ACI processes may be necessary in weather and climate models to study ACI effectively. © 2020 American Meteorological Society."
"57219714797;55720332500;7403143315;","Expansion of a size disaggregation profile library for particulate matter emissions processing from three generic profiles to 36 source-type-specific profiles",2020,"10.1080/10962247.2020.1743794","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85094879471&doi=10.1080%2f10962247.2020.1743794&partnerID=40&md5=bd9314854c02f068fdce2cb174558a27","This study describes a significant upgrade to the particulate matter (PM) size disaggregation profile library used for preparing emissions files for the GEM-MACH (Global Environmental Multiscale-Modelling Air-quality and CHemistry) chemical transport model (CTM). This model uses a sectional (bin) approach to represent the PM size distribution, where one configuration employs 12 size bins to disaggregate PM2.5 and PM10 inventory emissions into the first 10 bins ranging from 0.01 to 10.24 μm in diameter. For the size disaggregation step, a small library of three generic PM size disaggregation profiles is currently applied for three broad source categories (area, mobile, and point). However, as might be expected, these generic profiles are not always representative: for example, emissions from two very different area sources ‒ paved road dust and residential wood combustion ‒ are disaggregated using the same generic size distribution profile. In order to improve the current small PM size disaggregation profile library, a comprehensive literature review was conducted: over 100 relevant publications were identified and PM size distribution profiles for 36 different emission source types were selected and compiled. These 36 source-type-specific PM size distribution profiles were then combined based on process type with corresponding PM speciation profiles to create a library of chemically speciated and size-resolved PM disaggregation profiles. This library can now be used by the SMOKE (Sparse Matrix Operator Kernel Emissions) emissions processing system for the 12-bin version of GEM-MACH to perform PM chemical speciation and size allocation in one step. The size-profile data collected and compiled in this study may also be used for emissions processing for other CTMs with a size-resolved representation of PM. Details of the compilation of the 36 PM size disaggregation profiles are discussed, and the differences in processed PM emissions based on the current and updated PM size disaggregation profile libraries are shown. Implications: A new and expanded particulate matter (PM) size disaggregation profile library covering 36 emission source types has been developed based on an extensive literature review. Its use can produce significant changes in the size allocation of bulk PM inventory emissions processed for input to size-resolved PM chemical transport models. Such models are used to predict atmospheric visibility and to simulate the interactions of aerosol particles with atmospheric radiation and with clouds. The use of more accurate, size-resolved primary PM emissions by these models should improve their predictive skill for atmospheric PM processes affecting air quality, meteorology, and climate. © 2020 The Author(s). Published with license by Taylor & Francis Group, LLC."
"35847485400;6508206804;","Multiscale Integration of High-Resolution Spaceborne and Drone-Based Imagery for a High-Accuracy Digital Elevation Model Over Tristan da Cunha",2020,"10.3389/feart.2020.00319","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85091417193&doi=10.3389%2ffeart.2020.00319&partnerID=40&md5=e3b345a35f3d1ea4316c15420f1e0e52","Very high-resolution (VHR) optical Earth observation (EO) satellites as well as low-altitude and easy-to-use unmanned aerial systems (UAS/drones) provide ever-improving data sources for the generation of detailed 3-dimensional (3D) data using digital photogrammetric methods with dense image matching. Today both data sources represent cost-effective alternatives to dedicated airborne sensors, especially for remote regions. The latest generation of EO satellites can collect VHR imagery up to 0.30 m ground sample distance (GSD) of even the most remote location from different viewing angles many times per year. Consequently, well-chosen scenes from growing image archives enable the generation of high-resolution digital elevation models (DEMs). Furthermore, low-cost and easy to use drones can be quickly deployed in remote regions to capture blocks of images of local areas. Dense point clouds derived from these methods provide an invaluable data source to fill the gap between globally available low-resolution DEMs and highly accurate terrestrial surveys. Here we investigate the use of archived VHR satellite imagery with approx. 0.5 m GSD as well as low-altitude drone-based imagery with average GSD of better than 0.03 m to generate high-quality DEMs using photogrammetric tools over Tristan da Cunha, a remote island in the South Atlantic Ocean which lies beyond the reach of current commercial manned airborne mapping platforms. This study explores the potentials and limitations to combine this heterogeneous data sources to generate improved DEMs in terms of accuracy and resolution. A cross-validation between low-altitude airborne and spaceborne data sets describes the fit between both optical data sets. No co-registration error, scale difference or distortions were detected, and a quantitative cloud-to-cloud comparison showed an average distance of 0.26 m between both point clouds. Both point clouds were merged applying a conventional georeferenced approach. The merged DEM preserves the rich detail from the drone-based survey and provides an accurate 3D representation of the entire study area. It provides the most detailed model of the island to date, suitable to support practical and scientific applications. This study demonstrates that combination archived VHR satellite and low-altitude drone-based imagery provide inexpensive alternatives to generate high-quality DEMs. © Copyright © 2020 Backes and Teferle."
"36908360800;57219371154;57189027721;6506313924;6602093215;9536332800;57051148400;","Statistical model for filamentary structures of molecular clouds: The modified multiplicative random cascade model and its multifractal nature",2020,"10.1051/0004-6361/201937085","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85092431430&doi=10.1051%2f0004-6361%2f201937085&partnerID=40&md5=c2c931ac18d3ba5adecccd4ff8faef3e","We propose a new statistical model that can reproduce the hierarchical nature of the ubiquitous filamentary structures of molecular clouds. This model is based on the multiplicative random cascade, which is designed to replicate the multifractal nature of intermittency in developed turbulence. We present a modified version of the multiplicative process where the spatial fluctuations as a function of scales are produced with the wavelet transforms of a fractional Brownian motion realisation. This simple approach produces naturally a log-normal distribution function and hierarchical coherent structures. Despite the highly contrasted aspect of these coherent structures against a smoother background, their Fourier power spectrum can be fitted by a single power law. As reported in previous works using the multiscale non-Gaussian segmentation (MnGSeg) technique, it is proven that the fit of a single power law reflects the inability of the Fourier power spectrum to detect the progressive non-Gaussian contributions that are at the origin of these structures across the inertial range of the power spectrum. The mutifractal nature of these coherent structures is discussed, and an extension of the MnGSeg technique is proposed to calculate the multifractal spectrum that is associated with them. Using directional wavelets, we show that filamentary structures can easily be produced without changing the general shape of the power spectrum. The cumulative effect of random multiplicative sequences succeeds in producing the general aspect of filamentary structures similar to those associated with star-forming regions. The filamentary structures are formed through the product of a large number of random-phase linear waves at different spatial wavelengths. Dynamically, this effect might be associated with the collection of compressive processes that occur in the interstellar medium. © 2020 J.-F. Robitaille et al."
"36560513500;42262168900;","Comparison of filters for archaeology-specific ground extraction from airborne LiDAR point clouds",2020,"10.3390/RS12183025","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85092252090&doi=10.3390%2fRS12183025&partnerID=40&md5=e4e8fa358bac60021dff0242f4e7b10e","Identifying bare-earth or ground returns within point cloud data is a crucially important process for archaeologists who use airborne LiDAR data, yet there has thus far been very little comparative assessment of the available archaeology-specific methods and their usefulness for archaeological applications. This article aims to provide an archaeology-specific comparison of filters for ground extraction from airborne LiDAR point clouds. The qualitative and quantitative comparison of the data from four archaeological sites from Austria, Slovenia, and Spain should also be relevant to other disciplines that use visualized airborne LiDAR data. We have compared nine filters implemented in free or low-cost off-the-shelf software, six of which are evaluated in this way for the first time. The results of the qualitative and quantitative comparison are not directly analogous, and no filter is outstanding compared to the others. However, the results are directly transferable to real-world problem-solving: Which filter works best for a given combination of data density, landscape type, and type of archaeological features? In general, progressive TIN (software: lasground_new) and a hybrid (software: Global Mapper) commercial filter are consistently among the best, followed by an open source slope-based one (software: Whitebox GAT). The ability of the free multiscale curvature classification filter (software: MCC-LIDAR) to remove vegetation is also commendable. Notably, our findings show that filters based on an older generation of algorithms consistently outperform newer filtering techniques. This is a reminder of the indirect path from publishing an algorithm to filter implementation in software. © 2020 by the authors."
"7401662157;57218676222;7005566228;56568251300;7103332462;36237885400;7005805931;56566873100;6603570734;8547622700;57204226332;35377433200;55750223500;57218675801;57203067199;35238413800;23061889500;57202847250;6701467496;8318213100;7202929125;56512202800;57204797002;7403258846;8355600600;56342326600;57202952564;15822192800;55757586800;57194606597;7402935899;36976168000;7004002583;57203026080;12790268500;35242015200;55705656800;7403536449;55231989000;57218669464;7005084542;57206389610;24170690100;55210722100;55874635700;6602882601;55673595500;7005672565;9234005200;7003509373;22834101100;57218670776;57218674516;57194592820;57194798843;6603664735;57218670823;16549809400;55226383000;24074312000;35330159300;57215516631;57202322208;56812610800;25627568300;55492802400;55750138400;57218674884;7005283695;36571804600;7601365384;7409321582;34770134800;55671720700;57194595458;35773361100;57189663358;36238131700;56455301400;55370384000;57194605392;57209260420;35330124000;57190230987;35748985900;37056945900;57209285153;56252021400;7405326474;35185338100;56436978700;57194603379;7409459358;55727743600;36238023800;6508022172;35569334500;7003401658;13310130800;7201941871;36714093500;7202558313;18936782900;35096693300;16070455300;6602816367;38862759600;7403068909;7004265198;57194586988;57218670903;56800212700;7407452361;15844178300;6603887796;6604032293;35482578500;27868095600;36971326200;7003564783;7501737823;7006011851;43361931100;55441261000;55170380200;57209281402;57199325064;49865000200;56493265600;57207478624;56183368700;36955785700;7202964254;35308644100;7004237751;7004415016;14042952700;36908360800;","The JCMT BISTRO Survey: Magnetic Fields Associated with a Network of Filaments in NGC 1333",2020,"10.3847/1538-4357/aba1e2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089983713&doi=10.3847%2f1538-4357%2faba1e2&partnerID=40&md5=d823db0e2f5e28946fb6a119fffea2c4","We present new observations of the active star formation region NGC 1333 in the Perseus molecular cloud complex from the James Clerk Maxwell Telescope B-Fields In Star-forming Region Observations (BISTRO) survey with the POL-2 instrument. The BISTRO data cover the entire NGC 1333 complex (∼1.5 pc ? 2 pc) at 0.02 pc resolution and spatially resolve the polarized emission from individual filamentary structures for the first time. The inferred magnetic field structure is complex as a whole, with each individual filament aligned at different position angles relative to the local field orientation. We combine the BISTRO data with low- and high- resolution data derived from Planck and interferometers to study the multiscale magnetic field structure in this region. The magnetic field morphology drastically changes below a scale of ∼1 pc and remains continuous from the scales of filaments (∼0.1 pc) to that of protostellar envelopes (∼0.005 pc or ∼1000 au). Finally, we construct simple models in which we assume that the magnetic field is always perpendicular to the long axis of the filaments. We demonstrate that the observed variation of the relative orientation between the filament axes and the magnetic field angles are well reproduced by this model, taking into account the projection effects of the magnetic field and filaments relative to the plane of the sky. These projection effects may explain the apparent complexity of the magnetic field structure observed at the resolution of BISTRO data toward the filament network. © 2020. The American Astronomical Society. All rights reserved.."
"57219023977;21934546200;57219033143;57216870364;6602211600;","Change Detection in Photogrammetric Point Clouds for Monitoring of Alpine, Gravitational Mass Movements",2020,"10.5194/isprs-annals-V-2-2020-687-2020","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85091078392&doi=10.5194%2fisprs-annals-V-2-2020-687-2020&partnerID=40&md5=4bf6a3896a249b4790dafc53f012fa4c","This contribution discusses the accuracy and the applicability of Photogrammetric point clouds based on dense image matching for the monitoring of gravitational mass movements caused by crevices. Four terrestrial image sequences for three different time epochs have been recorded and oriented using ground control point in a local reference frame. For the first epoch, two sequences are recorded, one in the morning and one in the afternoon to evaluate the noise level within the point clouds for a static geometry and changing light conditions. The second epoch is recorded a few months after the first epoch where also no significant change has occurred in between. The third epoch is recorded after one year with changes detected. As all point clouds are given in the same local coordinate frame and thus are co-registered via the ground control points, change detection is based on calculating the Multiscale-Model-to-Model-Cloud distances (M3C2) of the point clouds. Results show no movements for the first year, but identify significant movements comparing the third epoch taken in the second year. Besides the noise level estimation, the quality checks include the accuracy of the camera orientations based on ground control points, the covariances of the bundle adjustment, and a comparison the Geodetic measurements of additional control points and a laser scanning point cloud of a part of the crevice. Additionally, geological measurements of the movements have been performed using extensometers. © 2020 Copernicus GmbH. All rights reserved."
"57191623267;6508387490;25637618400;12042290600;","Semi-Automatic Rock Mass Geometry Analysis from A Dense 3D Point Cloud with Discontinuitylab",2020,"10.5194/isprs-annals-V-2-2020-679-2020","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85091071844&doi=10.5194%2fisprs-annals-V-2-2020-679-2020&partnerID=40&md5=c10529927464c3dc5d33d89d7952839d","2D and 3D imageries can allow the optimization of rock mass exploitation (quarries, roads, rail networks, open pit, potentially tunnels and underground mines networks). The increasingly common use of photogrammetry makes it possible to obtain georeferenced 3D point clouds that are useful for understanding the rock mass. Indeed, new structural analysis solutions have been proposed since the advent of the 3D technologies. These methods are essentially focused on the production of digital stereonet. Production of additional information from 3D point clouds are possible to better define the structure of the rock mass, in particular the quantification of the discontinuities density. The aim of this paper is to test and validate a new method that provides statistics on the distances between the discontinuity planes. This solution is based on exploiting the information previously extracted from the segmentation of the discontinuity planes of a point cloud and their classification in family. In this article, the proposed solution is applied on two multiscale examples, firstly to validate it with a virtual synthetic outcrop and secondly to test it on a real outcrop. To facilitate these analyses, a software called DiscontinuityLab has been developed and used for the treatments. © 2020 Copernicus GmbH. All rights reserved."
"55907137600;57197328825;6602363573;24167564500;56583271600;8888621200;56959149600;34971872500;35768562400;56403904000;6701378450;55879773000;14322460000;23018141700;7004496942;7102294773;6602635781;8911477400;","A multiphase CMAQ version 5.0 adjoint",2020,"10.5194/gmd-13-2925-2020","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85088310443&doi=10.5194%2fgmd-13-2925-2020&partnerID=40&md5=467da46ee6d531e5ee7e4b870c9f538c","We present the development of a multiphase adjoint for the Community Multiscale Air Quality (CMAQ) model, a widely used chemical transport model. The adjoint model provides location- and time-specific gradients that can be used in various applications such as backward sensitivity analysis, source attribution, optimal pollution control, data assimilation, and inverse modeling. The science processes of the CMAQ model include gas-phase chemistry, aerosol dynamics and thermodynamics, cloud chemistry and dynamics, diffusion, and advection. Discrete adjoints are implemented for all the science processes, with an additional continuous adjoint for advection. The development of discrete adjoints is assisted with algorithmic differentiation (AD) tools. Particularly, the Kinetic PreProcessor (KPP) is implemented for gas-phase and aqueous chemistry, and two different automatic differentiation tools are used for other processes such as clouds, aerosols, diffusion, and advection. The continuous adjoint of advection is developed manually. For adjoint validation, the brute-force or finite-difference method (FDM) is implemented process by process with box- or columnmodel simulations. Due to the inherent limitations of the FDM caused by numerical round-off errors, the complex variable method (CVM) is adopted where necessary. The adjoint model often shows better agreement with the CVM than with the FDM. The adjoints of all science processes compare favorably with the FDM and CVM. In an example application of the full multiphase adjoint model, we provide the first estimates of how emissions of particulate matter (PM2:5) affect public health across the US. © 2020 Copernicus GmbH. All rights reserved."
"57207473157;55899884100;7401436524;57209413320;57209422031;57218196192;8905764300;","A multiscale dynamical model in a dry-mass coordinate for weather and climate modeling: Moist dynamics and its coupling to physics",2020,"10.1175/MWR-D-19-0305.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85088227551&doi=10.1175%2fMWR-D-19-0305.1&partnerID=40&md5=05c2146b5812eb182b47ae9fbd0c8cbb","A multiscale dynamical model for weather forecasting and climate modeling is developed and evaluated in this study. It extends a previously established layer-averaged, unstructured-mesh nonhydrostatic dynamical core (dycore) to moist dynamics and parameterized physics in a dry-mass vertical coordinate. The dycore and tracer transport components are coupled in a mass-consistent manner, with the dycore providing time-averaged horizontal mass fluxes to passive transport, and tracer transport feeding back to the dycore with updated moisture constraints. The vertical mass flux in the tracer transport is obtained by reevaluating the mass continuity equation to ensure compatibility. A general physics-dynamics coupling workflow is established, and a dycore-tracer-physics splitting strategy is designed to couple these components in a flexible and efficient manner. In this context, two major physics-dynamics coupling strategies are examined. Simple-physics packages from the 2016 Dynamical Core Model Intercomparison Project (DCMIP2016) experimental protocols are used to facilitate the investigation of the model behaviors in idealized moist-physics configurations, including cloud-scale modeling, weather forecasting, and climate modeling, and in a real-world test-case setup. Performance evaluation demonstrates that the model is able to produce reasonable sensitivity and variability at various spatiotemporal scales. The consideration and implications of different physics-dynamics coupling options are discussed within this context. The appendix provides discussion on the energetics in the continuous- and discrete-form equations of motion. © 2020 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses)."
"54787703600;24492458800;15765075000;15765075000;","Improving sub-canopy snow depth mapping with unmanned aerial vehicles: Lidar versus structure-from-motion techniques",2020,"10.5194/tc-14-1919-2020","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85087209776&doi=10.5194%2ftc-14-1919-2020&partnerID=40&md5=bf425e4be05440f4ee847097c3c71197","Vegetation has a tremendous influence on snow processes and snowpack dynamics, yet remote sensing techniques to resolve the spatial variability of sub-canopy snow depth are not always available and are difficult from spacebased platforms. Unmanned aerial vehicles (UAVs) have had recent widespread application to capture high-resolution information on snow processes and are herein applied to the sub-canopy snow depth challenge. Previous demonstrations of snow depth mapping with UAV structure from motion (SfM) and airborne lidar have focussed on non-vegetated surfaces or reported large errors in the presence of vegetation. In contrast, UAV-lidar systems have high-density point clouds and measure returns from a wide range of scan angles, increasing the likelihood of successfully sensing the subcanopy snow depth. The effectiveness of UAV lidar and UAV SfM in mapping snow depth in both open and forested terrain was tested in a 2019 field campaign at the Canadian Rockies Hydrological Observatory, Alberta, and at Canadian prairie sites near Saskatoon, Saskatchewan, Canada. Only UAV lidar could successfully measure the sub-canopy snow surface with reliable sub-canopy point coverage and consistent error metrics (root mean square error (RMSE) <0:17 m and bias-0:03 to-0:13 m). Relative to UAV lidar, UAV SfM did not consistently sense the sub-canopy snow surface, the interpolation needed to account for point cloud gaps introduced interpolation artefacts, and error metrics demonstrated relatively large variability (RMSE<0:33 m and bias 0.08 to-0:14 m). With the demonstration of sub-canopy snow depth mapping capabilities, a number of early applications are presented to showcase the ability of UAV lidar to effectively quantify the many multiscale snow processes defining snowpack dynamics in mountain and prairie environments. © 2020 Author(s)."
"57216939162;34978723300;57216932843;56665111500;7410204041;","Sensitivity study of WRF simulations over tanzania for extreme events during wet and dry seasons",2020,"10.3390/ATMOS11050459","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85085386374&doi=10.3390%2fATMOS11050459&partnerID=40&md5=c218e1bffd15d58232b6f5b6b3433ab1","Precipitation prediction is important to help mitigate the effects of drought and floods on various social and economic activities. This research is to improve the forecasting skill over Tanzania by providing suitable combinations of physical parameterization schemes and horizontal grid spacing of the Weather Research Forecasting (WRF) model for daily forecasting over Tanzania. The performance of different schemes on the precipitation systems during the wet and dry seasons over Tanzania is evaluated such that the sensitivity tests was performed for the WRF model at different horizontal resolutions, and for different physical parameterization schemes (convective and cloud microphysics). The results showed that the improved grid spacing was better at completing forecasts during the wet season, but had little significant impacts during the dry season. Model simulations with combinations of Lin et al. microphysics and the multiscale Kain-Fritsch scheme showed greater success during the both seasons; therefore, these combinations were recommended for Tanzania to resolve weather systems during the wet and dry season simulations, respectively. © 2020 by the authors."
"56621591000;55214935900;27169720300;57212864075;56506577800;","Damage signature generation of revetment surface along urban rivers using UAV-based mapping",2020,"10.3390/ijgi9040283","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85083775134&doi=10.3390%2fijgi9040283&partnerID=40&md5=38f03b19930b01b9ac9f3becf87b97a3","The all-embracing inspection of geometry structures of revetments along urban rivers using the conventional field visual inspection is technically complex and time-consuming. In this study, an approach using dense point clouds derived from low-cost unmanned aerial vehicle (UAV) photogrammetry is proposed to automatically and efficiently recognize the signatures of revetment damage. To quickly and accurately recover the finely detailed surface of a revetment, an object space-based dense matching approach, that is, region growing coupled with semi-global matching, is exploited to generate pixel-by-pixel dense point clouds for characterizing the signatures of revetment damage. Then, damage recognition is conducted using a proposed operator, that is, a self-adaptive and multiscale gradient operator, which is designed to extract the damaged regions with different sizes in the slope intensity image of the revetment. A revetment with slope protection along urban rivers is selected to evaluate the performance of damage recognition. Results indicate that the proposed approach can be considered an effective alternative to field visual inspection for revetment damage recognition along urban rivers because our method not only recovers the finely detailed surface of the revetment but also remarkably improves the accuracy of revetment damage recognition. © 2020 by the authors. Licensee MDPI, Basel, Switzerland."
"55022909500;36698019400;57212777181;","Using UAV and LiDAR data for gully geomorphic changes monitoring",2020,"10.1016/B978-0-444-64177-9.00010-2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85083295922&doi=10.1016%2fB978-0-444-64177-9.00010-2&partnerID=40&md5=4d44e4156f4819d8ed0c90c2c7951f73","Gully formation and evolution represent important aspects not only of landform evolution, but also of practical interest regarding hydrology and agriculture. The classic methodology of assessing the intensity of these erosion processes, and the volumes of sediments involved, is to use field measurements or classical/digital photogrammetry. These methods were recently completed by the use of high-resolution digital elevation models (DEMs) derived from multitemporal LiDAR data and UAV images. In the Moldavian Plateau (northeastern Romania), gullies are common landforms due to geologic, topographic, climatic, and anthropic factors. Their episodic development and the relationship with high rainfall and/or snowmelt events constitute a key point in the deciphering of the gully evolution. For this work we have chosen the case of four gullies developed in the lacustrine deposits of abandoned anthropic reservoirs which presented an obvious dynamic in the last two decades on remote sensing images. A DJI Phantom 4 Pro UAV was flown over the study case areas and acquired images with 80% side and forward overlap at 20 MP resolution. The UAV point cloud was obtained using the structure from motion (SfM) technique in VisualSFM open source software from overlapping images and was georeferenced with ground control points. Georeferenced LiDAR point clouds acquired in winter 2012 were used as a reference dataset. The filtering of the point clouds for obtaining bare ground points was performed with the multiscale curvature classification algorithm. The point cloud ground data for both the sources and periods were used to interpolate a 0.25-m resolution bare earth DEM for every gully. This LiDAR reference DEM was used together with the UAV SfM DEM for deriving the DEM of differences (DoDs) using the geomorphic change detection (GCD) technique of Wheaton et al. (2010) implemented in SAGA GIS and R stat. GCD was applied with both uniform and spatially variable thresholding, the threshold errors being derived from GCPs and from co-registration of DEMs. Geomorphological mapping was performed for establishing the spatially variable thresholds and for assessing the sediment budget. The results highlighted the areas that were affected by erosion and deposition and allowed us to evaluate the process rate for each studied gully, each gully element, and to derive a raw sediment budget, showing that LiDAR, UAV SfM, and DoD are useful methods in geomorphological mapping and rate of process studies. © 2020 Elsevier B.V."
"57218308981;7403282069;","Arctic Clouds Simulated by a Multiscale Modeling Framework and Comparisons With Observations and Conventional GCMs",2020,"10.1029/2019JD030522","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85078284644&doi=10.1029%2f2019JD030522&partnerID=40&md5=cdacd2c73528a81ca312eff3ad253c00","Clouds are an important component of the Arctic climate system through their regulation of the surface energy budget; however, Arctic clouds are poorly simulated in global climate models (GCMs). In this study, we evaluate the Arctic clouds simulated by a multiscale modeling framework (MMF). The results are compared against a merged CloudSat-CALIPSO radar-lidar cloud product and contrasted with an atmospheric reanalysis and conventional GCMs. The comparisons focus on the annual cycle of cloud covers, vertical structures of cloud fraction, and condensate mixing ratio, as well as the relationships between low-cloud cover and atmospheric static stability. The MMF is found to represent Arctic boundary layer clouds slightly more realistically than the reanalysis and GCMs in both the annual cycle and vertical distribution except that middle- and high-cloud covers are underestimated and the amplitude of annual cycle of total cloud cover is larger. The relationship between low-cloud cover and near-surface atmospheric stability produced by MMF is remarkably similar to the satellite observation during autumn, winter, and early spring, as low-cloud cover decreases with colder surface and stronger stability. Such relationships over the annual cycle are not reproduced by other modeling approaches. Lastly, MMF yields a positive correlation between low-cloud cover and atmospheric stability over the Arctic ocean from May to August, opposite to the satellite observation, implying stronger control of horizontal advection on low-cloud formation. This modeled relationship is contributed by cloud fraction near the surface, which is known to be underestimated due to radar's surface clutter. © 2019. American Geophysical Union. All Rights Reserved."
"55606974300;8511991900;34881780600;8922308700;15755995900;56384704800;","Can the Multiscale Modeling Framework (MMF) Simulate the MCS-Associated Precipitation Over the Central United States?",2019,"10.1029/2019MS001849","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077380971&doi=10.1029%2f2019MS001849&partnerID=40&md5=76728257cadbdafaada336aa340e9dd8","Mesoscale convective systems (MCSs) are a major source of precipitation in many regions of the world. Traditional global climate models (GCMs) do not have adequate parameterizations to represent MCSs. In contrast, the Multiscalex Modeling Framework (MMF), which explicitly resolves convection within the cloud-resolving model embedded in each GCM column, has been shown to be a promising tool for simulating MCSs, particularly over the Tropics. In this work, we use ground-based radar-observed precipitation, North American Regional Reanalysis data, and a high-resolution Weather Research and Forecasting simulation to evaluate in detail the MCS-associated precipitation over the central United States predicted by a prototype MMF simulation that has a 2° host-GCM grid. We show that the prototype MMF with nudged winds fails to capture the convective initiation in three out of four major MCS events during May 201x1 and underpredicts the precipitation rates for the remaining event, because the model cannot resolve the mesoscale drylines/fronts that are important drivers for initiating convection over the Southern Great Plains region. By reducing the host-GCM grid spacing to 0.25° in the MMF and nudging the winds, the simulation is able to better capture the mesoscale dynamics, which drastically improves the model performance. We also show that the MMF model performs better than the traditional GCM in capturing the precipitation intensity. Our results suggest that increasing resolution plays a dominant role in improving the simulation of precipitation in the MMF, and the cloud-resolving model embedded in each GCM column further helps to boost precipitation rate. ©2019. The Authors."
"36908360800;6602093215;7101829072;55082407500;6603810234;","Exposing the plural nature of molecular clouds: Extracting filaments and the cosmic infrared background against the true scale-free interstellar medium",2019,"10.1051/0004-6361/201935545","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85090050562&doi=10.1051%2f0004-6361%2f201935545&partnerID=40&md5=286f61e415409ad18277293f59df22db","We present the Multiscale non-Gaussian Segmentation (MnGSeg) analysis technique. This wavelet-based method combines the analysis of the probability distribution function (PDF) of map fluctuations as a function of spatial scales and the power spectrum analysis of a map. This technique allows us to extract the non-Gaussianities identified in the multiscaled PDFs usually associated with turbulence intermittency and to spatially reconstruct the Gaussian and the non-Gaussian components of the map. This new technique can be applied on any data set. In the present paper, it is applied on a Herschel column density map of the Polaris flare cloud. The first component has by construction a self-similar fractal geometry similar to that produced by fractional Brownian motion (fBm) simulations. The second component is called the coherent component, as opposed to fractal, and includes a network of filamentary structures that demonstrates a spatial hierarchical scaling (i.e. filaments inside filaments). The power spectrum analysis of the two components proves that the Fourier power spectrum of the initial map is dominated by the power of the coherent filamentary structures across almost all spatial scales. The coherent structures contribute increasingly from larger to smaller scales, without producing any break in the inertial range. We suggest that this behaviour is induced, at least partly, by inertial-range intermittency, a well-known phenomenon for turbulent flows. We also demonstrate that the MnGSeg technique is itself a very sensitive signal analysis technique that allows the extraction of the cosmic infrared background (CIB) signal present in the Polaris flare submillimetre observations and the detection of a characteristic scale for 0.1 ≲ l ≲ 0.3 pc. The origin of this characteristic scale could partly be the transition of regimes dominated by incompressible turbulence versus compressible modes and other physical processes, such as gravity. © J.-F. Robitaille et al. 2019."
"57209605840;57203070803;14018992700;","Voxel-Based Attribute Profiles on LIDAR Data for Land Cover Mapping",2019,"10.1109/IGARSS.2019.8899129","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077720196&doi=10.1109%2fIGARSS.2019.8899129&partnerID=40&md5=bc2b72f8850a3c62741dcd3c6118c61c","This paper deals with strategies for LiDAR data analysis. While a large majority of studies first rasterize 3D point clouds onto regular 2D grids and then use 2D image processing tools for characterizing data, our work rather suggests to keep as long as possible the 3D structure by computing features on 3D data and rasterize later in the process. By this way, the vertical component is still taken into account. In practice, a voxelization step of raw data is performed in order to exploit mathematical tools defined on regular volumes. More precisely, we focus on attribute profiles that have been shown to be very efficient features to characterize remote sensing scenes. They require the computation of an underlying hierarchical structure (through a Max-Tree). Experimental results obtained on urban LiDAR data classification support the performances of this strategy compared with an early rasterization process. © 2019 IEEE."
"57195958231;8211380400;56594344600;8950138100;56707853300;56403904000;","Drought Impacts on Secondary Organic Aerosol: A Case Study in the Southeast United States",2019,"10.1021/acs.est.8b04842","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85058785445&doi=10.1021%2facs.est.8b04842&partnerID=40&md5=22f5f18679e1ef547f4ebe85d9726b91","Secondary organic aerosol (SOA) is a significant component of fine particulate matter, and it has increased during past drought periods in the U.S. Here, we use the Community Multiscale Air Quality (CMAQ) model to characterize the complex effects of drought on SOA through a case study comparing a drought period (June 2011) and a wet period (June 2013) over the southeast U.S. The model simulates a 68% (1.7 μg/m 3 ) higher SOA concentration at the surface during drought and attributes 98% of this increase to biogenic SOA. Through model sensitivity simulations, the SOA increase associated with drought is attributed to 54% from accelerated gas-phase reactions oxidizing volatile organic compounds (VOCs) to SOA, 45% from higher emissions of biogenic VOCs, 18% from enhanced acid-catalyzed production of isoprene SOA in aerosol water due to changing sulfate, 3% from enhanced in-cloud aqueous phase chemistry. Because the higher SOA levels overwhelm the reduced precipitation, there is an increase in wet deposition flux in the drought month which offsets 20% of the total SOA increase. If anthropogenic emissions are held constant, anthropogenic SOA is 51% higher during drought, highlighting the importance of meteorological impacts on chemistry. © 2018 American Chemical Society."
"14523438100;22935689600;","Statistical methods for multiscale analysis of interplanetary magnetic field fluctuations",2019,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85091404074&partnerID=40&md5=8fa45e097bfe990247c85eee7e3bfd53","An ICME event can be observed between DOY 23.958 - DOY 24.854, 2001, its signatures being analyzed in this paper considering the data from Ulysses/VHM and SWOOPS instruments. The presence of a magnetic cloud in the interval DOY 23.958 - DOY 24.665 is also analyzed by means of the minimum variance analysis (MVA). The technique based on differencing of the original time series over a range of temporal scales is applied for the study of statistical properties of the interplanetary magnetic field fluctuations along a period of three days, starting on DOY 23, 2001. The intermittency, that is connected with sudden occurrence of large amplitude variations of magnetic field intensity, is usually pointed out as a departure of the probability distribution functions (PDFs) from a Gaussian distribution. For the studied period of time, the fluctuations of the magnetic field magnitude (B), and the corresponding RTN components (Br, Bt, Bn) at larger scales are less intermittent than at small scales. Also, their behavior at different scales is quantitatively described by the PDFs and generalized structure functions. © 2020 The Authors. Journal of Virus Eradication published by Mediscript"
"56434851400;7004978125;55176818100;","Effects of rotation on the multiscale organization of convection in a global 2D cloud-resolving model",2019,"10.1175/JAS-D-19-0041.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85075545993&doi=10.1175%2fJAS-D-19-0041.1&partnerID=40&md5=fd1f20d4d3a9dd058511997c28319aa3","Atmospheric convection exhibits distinct spatiotemporal variability at different latitudes. A good understanding of the effects of rotation on the multiscale organization of convection from the mesoscale to synoptic scale to planetary scale is still lacking. Here cloud-resolving simulations with fixed surface fluxes and radiative cooling are implemented with constant rotation in a two-dimensional (2D) planetary domain to simulate multiscale organization of convection from the tropics to midlatitudes. All scenarios are divided into three rotation regimes (weak, order-one, and strong) to represent the idealized ITCZ region (0°–6°N), the Indian monsoon region (6°–20°N), and the midlatitude region (20°–45°N), respectively. In each rotation regime, a multiscale asymptotic model is derived systematically and used as a diagnostic framework for energy budget analysis. The results show that planetary-scale organization of convection only arises in the weak rotation regime, while synoptic-scale organization dominates (vanishes) in the order-one (strong) rotation regime. The depletion of planetary-scale organization of convection as the magnitude of rotation increases is attributed to the reduced planetary kinetic energy of zonal winds, mainly due to the decreasing acceleration effect by eddy zonal momentum transfer from mesoscale convective systems (MCSs) and the increasing deceleration effect by the Coriolis force. Similarly, the maintenance of synoptic-scale organization is related to the acceleration effect by MCSs. Such decreasing acceleration effects by MCSs on both planetary and synoptic scales are further attributed to less favorable conditions for convection provided by weaker background vertical shear of the zonal winds, resulting from the increasing magnitude of rotation. © 2019 American Meteorological Society."
"36705265400;56533742600;36339753800;","Pair correlations and spatial statistics of deep convection over the Tropical Atlantic",2019,"10.1175/JAS-D-18-0326.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85075529254&doi=10.1175%2fJAS-D-18-0326.1&partnerID=40&md5=cbc960c66eac716e57de3eee320e82c6","Over the tropical oceans, the large-scale, meridional circulation drives the accumulation of moist and warm air, leading to a relatively narrow, convectively active band. Therein, deep moist convection interacts with its heterogeneous environment—the intertropical convergence zone (ITCZ)—and organizes into multiscale structures that strongly impact Earth’s hydrological cycle and radiation budget. Understanding the spatial correlations and interactions among deep convective clouds is important, but challenging. These clouds are investigated in this study with the help of large-domain, storm-resolving simulations over the tropical Atlantic. Based on vertically integrated mass flux fields, deep convective updraft cells are identified with object-based techniques and analyzed with respect to their structural behavior and spatial arrangement. The pair-correlation method, which compares simulated pair numbers as a function of pair distance to an appropriately chosen reference, is applied and extended to allow for spatial statistics in a heterogeneous environment (i.e., the ITCZ). Based on pair-correlation analysis, the average probability is enhanced to find an updraft cell pair within 100 km compared to a random distribution. Additionally, the spatial arrangement of larger or stronger cells deviates more from randomness compared to smaller or weaker cells, which might be related to their stronger dynamical interaction mechanisms. Using simplified equilibrium statistics of interacting cells, several spatial characteristics of the storm-resolving simulations can be reproduced. © 2019 American Meteorological Society."
"24335361400;57195348393;6603566335;35613452300;","Resolving clouds in a global atmosphere model - A multiscale approach with nested models",2018,"10.1109/eScience.2018.00043","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85061352602&doi=10.1109%2feScience.2018.00043&partnerID=40&md5=d62bfe913d6d55d8f73d2ca60f1e90ad",[No abstract available]
"57205398436;55577486600;56134173900;","A method for multiscale estimation of leaf area index from time-series multi-source remote sensing data",2018,"10.1109/IGARSS.2018.8518373","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063136040&doi=10.1109%2fIGARSS.2018.8518373&partnerID=40&md5=9201ca00bb33de08c2018531092fcd99","Satellite observations are affected by clouds, aerosol and other factors, resulting in temporal discontinuities and spatial incompleteness in leaf area index (LAI) products. Furthermore, the currently available LAI products are generally retrieved from mono-temporal remote sensing data acquired by a single sensor, without comprehensive utilization of multi-source satellite observations. This paper proposes a new data assimilation method to retrieve temporally continuous LAI at different spatial scales from time-series multi-source remote sensing data with different spatial resolutions using an ensemble multiscale tree model (EnMsT). A dynamic model was constructed to describe the change rule of LAI in time series. At each time-step, the forecast of LAI from the dynamic model was used to construct an initial EnMsT. Then, satellite surface reflectance data with different spatial resolutions were used to update the LAI at each node of the EnMsT using an ensemble multiscale filter (EnMsF) technique. The final results demonstrate that this new method can estimate temporally continuous LAI at different spatial scales and the retrieved LAI values are in good agreement with the field measurements. © 2018 IEEE."
"55910516500;7005496535;","Quantifying the interplay between gravity and magnetic field in molecular clouds - A possible multiscale energy equipartition in NGC 6334",2018,"10.1093/mnras/stx2827","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042595290&doi=10.1093%2fmnras%2fstx2827&partnerID=40&md5=7f9bf8f882e4691c51a61f774723b51c","The interplay between gravity, turbulence and the magnetic field determines the evolution of the molecular interstellar medium (ISM) and the formation of the stars. In spite of growing interests, there remains a lack of understanding of the importance of magnetic field over multiple scales. We derive the magnetic energy spectrum - a measure that constraints the multiscale distribution of the magnetic energy, and compare it with the gravitational energy spectrum derived in Li &amp; Burkert. In our formalism, the gravitational energy spectrum is purely determined by the surface density probability density distribution (PDF), and the magnetic energy spectrum is determined by both the surface density PDF and the magnetic field-density relation. If regions have density PDFs close to P(Σ) ~ Σ-2 and a universal magnetic field-density relation B ~ ρ1/2, we expect a multiscale near equipartition between gravity and the magnetic fields. This equipartition is found to be true in NGC 6334, where estimates of magnetic fields over multiple scales (from 0.1 pc to a few parsec) are available. However, the current observations are still limited in sample size. In the future, it is necessary to obtain multiscale measurements of magnetic fields from different clouds with different surface density PDFs and apply our formalism to further study the gravity-magnetic field interplay. © 2017 The Author(s)."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051550379&partnerID=40&md5=ed71fe7d86fc29f0e162a0d85c14d004","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051539222&partnerID=40&md5=e176f02568c21b41b4006d530de65a22","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051522778&partnerID=40&md5=cccdfa832f8f7ddd1e5628c98af03e66","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051498772&partnerID=40&md5=c3b4f0b082b8a7ad5ee670214711c15d","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051496973&partnerID=40&md5=ad89e8ed8193dcfc1bcc3a44ba385872","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051494596&partnerID=40&md5=6f4586713f7aa25e12caee4f564f0cf2","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051480891&partnerID=40&md5=5dc50cd27f178a53415851e150ecaccc","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051444228&partnerID=40&md5=ea179e1f32f83194af685d173785185f","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051437017&partnerID=40&md5=b69aa24ccaead6da661ff2935d80feea","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051429716&partnerID=40&md5=a57fbd134128767256adb25e8594cd3e","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051428653&partnerID=40&md5=fce0e5379bf947bca755ee6f3d8fc3ce","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051420716&partnerID=40&md5=f9983de890ed66ce4ed57bcb7431aa3d","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051420664&partnerID=40&md5=a6b2c16f2a36f60345e186737cd14ba5","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051413377&partnerID=40&md5=57d0a55b0f719b631d6154bc1323a40a","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051402886&partnerID=40&md5=327cebb0b050cfbc6b681f48155f54ae","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Sustainable Construction Materials and Technologies",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051400581&partnerID=40&md5=51d7f0a8986658a0cd53d045e53e50cb","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051378032&partnerID=40&md5=02a197a8ef3341e992357dd00b3e20ec","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051375567&partnerID=40&md5=9dcd9796c700a4ff88b0517c72c7da1f","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
[No author id available],"Proceedings of the International Astronautical Congress, IAC",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85051372273&partnerID=40&md5=2d544ca81c88c1cb8d0c1ebafa6d81b0","The proceedings contain 1436 papers. The topics discussed include: the study on space-flight induced DNA damage in arabidopsis thaliana and the protective effect of hydrogen; anthropomorphic robots for cosmonauts support on space stations and space exploration applying prospects; reliability-based orbital design optimization for a earth observation satellite; potential scientific, practical, and cultural implications of discovering life in our solar system; Exomars 2020 mission: progress report on sample preparation and distribution system (SPDS) development; evolution of fragmentation cloud in highly eccentric orbit using representative objects; autonomy and operational concept for self-removal of spacecraft: status detection, removal triggering and passivation; axially displaced ellipse reflector antenna design and analysis using multilevel fast multipole accelerated method of moments solution of electric field integral equation; drones with stereo vision and robotic arms for assisting astronauts: a patent landscape and visualization analysis; an innovative modularized smartphone satellite with foldable configuration; kinematic steering enabling speed-constrained three-axes attitude control; heterogeneous multiscale methods for orbital dynamics; using additive/subtractive processing in the freeform fabrication of bi-metallic components; increasing the accuracy of electric sail mission performance estimates; fields experiment: lessons learned from a new tethered system for spacecraft docking; the first commercial airlock module: building the commercial space market; using a space flown relic to approach space to basic education schools and foster space culture; a fuzzy PID controller for solar sailing CubeSat; and making space for women: a more inclusive space policy in this Unispace+50."
"30667482600;57200082625;57188759509;55790615000;55575368100;","A scalable, automated system for photochemical modeling on the cloud",2017,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85039148284&partnerID=40&md5=afef899402a6440a6447cfce886f074b","Three-dimensional photochemical models are extensively used in air quality research and planning, including for the preparation of State Implementation Plans (SIPs) and the evaluation of the impact of new or expanded sources on O3 and PM2.5. However, running the variety of models and preprocessors necessary to prepare the inputs for photochemical modeling is complex and labor intensive. Here we present a scalable, cloud-based system that automates most of the needed steps for photochemical modeling: collecting the needed inputs from publically available sources or in-house archives; running the model; and performing some automatic analysis and quality checks on the output. This system, named AQcast, can currently be run for any region in the continental US. It consists of a meteorological component based on the Weather Research and Forecasting (WRF) model, an emissions component based on the US EPA 2011 National Emission Inventory (NEI) modeling platform, and a chemical transport model component based on the Community Multiscale Air Quality (CMAQ) model and the associated pre-processors. The system has been configured to run on cloud computing architectures, thus allowing an arbitrarily large number of simulations to be performed simultaneously. Furthermore, the input options for all components are read from a single XML file, thereby allowing both novice and expert users to submit their own photochemical modeling jobs to be run on the system. We will present modeling results from AQcast and describe our plans to expand the system to perform photochemical modeling over any region of the globe."
"55910516500;7005496535;","Constructing multiscale gravitational energy spectra from molecular cloud surface density PDF - interplay between turbulence and gravity",2016,"10.1093/mnras/stw1544","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84983740970&doi=10.1093%2fmnras%2fstw1544&partnerID=40&md5=b1521a094db346c4ee577a77ae4983e3","Gravity is believed to be important on multiple physical scales in molecular clouds. However, quantitative constraints on gravity are still lacking. We derive an analytical formula which provides estimates on multiscale gravitational energy distribution using the observed surface density probability distribution function (PDF). Our analytical formalism also enables one to convert the observed column density PDF into an estimated volume density PDF, and to obtain average radial density profile ρ(r). For a region with Ncol ∼ N-γN , the gravitational energy spectra is Ep(k) ∼ k-4(1-1/-γN). We apply the formula to observations of molecular clouds, and find that a scaling index of -2 of the surface density PDF implies that ρ ∼ r-2 and Ep(k) ∼ k-2. The results are valid from the cloud scale (a few parsec) to around ∼0.1 pc. Because of the resemblance the scaling index of the gravitational energy spectrum and the that of the kinetic energy power spectrum of the Burgers turbulence (where E ∼ k-2), our result indicates that gravity can act effectively against turbulence over a multitude of physical scales. This is the critical scaling index which divides molecular clouds into two categories: clouds like Orion and Ophiuchus have shallower power laws, and the amount of gravitational energy is too large for turbulence to be effective inside the cloud. Because gravity dominates, we call this type of cloud g-type clouds. On the other hand, clouds like the California molecular cloud and the Pipe nebula have steeper power laws, and turbulence can overcome gravity if it can cascade effectively from the large scale. We call this type of cloud t-type clouds. The analytical formula can be used to determine if gravity is dominating cloud evolution when the column density PDF can be reliably determined. © 2016 The Authors."
"6603735862;","Turbulence and waves in the upper troposphere and lower stratosphere",2016,"10.1007/978-3-319-23630-8_20","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85017090971&doi=10.1007%2f978-3-319-23630-8_20&partnerID=40&md5=abb28b4b36f50b923728c5c557597fd3","The generation mechanisms and physical characteristics of jet stream turbulence, mountain, and inertia-gravity waves in the upper troposphere and lower stratosphere (UTLS) are investigated for real atmospheric conditions. To resolve multi-scale physical processes of wave breaking and laminated structures in the UTLS region, vertical nesting and adaptive vertical gridding have been developed and applied in nested, high-resolution, coupled mesoscale-microscale simulations. The fully three-dimensional, moist, compressible Navier-Stokes equations are solved with a stretched, adaptive grid in the vertical and improved resolution in the UTLS region. For verification purposes, real-case simulations are conducted for the Terrain-Induced Rotor Experiment (T-REX) campaign of measurements and selected cases from pilot reports (PIREPs). Comparisons with observational datasets highlight significant benefits of nested computational techniques that take into account the shear-stratified turbulence physics of the UTLS. Localized sharp shear layers characterized by stiff gradients of potential temperature and strong alternating vertical velocity patches are resolved in the tropopause region within the embedded microscale nest. We describe fully three-dimensional multiscale dynamics of laminated structures and nonlinear processes in turbulent layers observed in the UTLS region. Depending on atmospheric conditions, the gravity waves might be trapped at the altitude of the jet stream and break or propagate into higher altitudes acquiring characteristics of inertia-gravity waves. Threedimensional instabilities in nonparallel shear-stratified flows such as those induced by mountain and polarized inertia-gravity waves in UTLS are characterized by a polarized Richardson number. © Springer International Publishing Switzerland 2016."
"6508333712;24398842400;","Spatial and temporal variability of clouds and precipitation over Germany: Multiscale simulations across the ""gray zone""",2015,"10.5194/acpd-15-17135-2015","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042580284&doi=10.5194%2facpd-15-17135-2015&partnerID=40&md5=c6af381654beb2992da9595601c297ca","This paper assesses the resolution dependance of clouds and precipitation over Germany by numerical simulations with the COnsortium for Small-scale MOdeling (COSMO) model. Six intensive observation periods of the HOPE (HD(CP)2 Observational Prototype Experiment) measurement campaign conducted in spring 2013 and one summer day of the same year are simulated. By means of a series of grid-refinement resolution tests (horizontal grid spacing 2.8, 1 km, 500 and 250 m), the applicability of the COSMO model to real weather events in the terra incognita, i. e. the scale ranging between the mesoscale limit (no turbulence resolved) and the large-eddy simulation limit (energy-containing turbulence resolved), is tested. It is found that although the representation of a number of processes is enhanced with resolution (e. g. boundary-layer thermals, low-level convergence zones, gravity waves), their influence on the temporal evolution of precipitation is rather weak. However, rain intensities may vary with resolution, leading to differences in the total rain amount of up to +48 %. Furthermore, the location of rain is similar for the springtime cases with moderate and strong synoptic forcing, whereas significant differences are obtained for the summertime case with air mass convection. Probability density functions of convection-related parameters are analyzed to investigate their dependance on model resolution and their impact on cloud formation and subsequent precipitation. © Author(s) 2015."
"56367751900;57211721709;55521761000;6507905123;","Three dimensional simulation of hydraulic fracturing on fault using lattice element method",2015,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85044190957&partnerID=40&md5=5d2218fb1dd55949c8c511a0025c43fd","Hydraulic fracturing (HF) is a mulit-scale and multi-physics process which makes numerical modelling challenging. Conventional numerical models focus on multi-physics nature of HF but the multiscale nature is compromised by idealization of reservoir to be continuous, homogeneous and isotropic. However, natural fractures take a significant role in the success of HF for exploration of unconventional resources like Shale gas. Advancement in microseismic monitoring provides useful data for simulation in a much greater details. There is an urgent need to develop a suitable numerical tool for multi-scale threedimensional simulation to better understand the roles of discontinuities and heterogeneity in reservoir and its interaction with HF, especially to address the environmental concerns such as induced seismicity. In this paper, a simple discontinuum numerical method - Lattice Element Method (LEM) is proposed to model HF in a large scale three-dimensional model. A reservoir is modelled as a lattice network composed of 1D Hookean's spring. Fracturing is modelled simply by removing lattices that meet a specified threshold as determined by the critical energy release rate of the rock. By introducing disorder in the model, mesh dependency in modelling fracture growth is minimized. Fluid flow is simplified as flow in pipe network and the permeability of pipe is related to fracture aperture by cubic flow law. Therefore, fracture flow and rock deformation are fully coupled. In this paper, four simulations of the same configuration except with different degrees of reservoir heterogeneity are presented. Fractures formed are diffusive and two groups of fracture are identified - connected fractures and isolated fracture without clear spatial correlation. The former forms a 'fracture cloud' and contributes to fluid flow and modeled by pipe network. The flow of fluid is highly tortuous and pipe network is sparely connected. The degree of reservoir heterogeneity controls the growth of 'fracture cloud' and pipe network. Microseismic monitoring often shows diffusive fracturing during HF on site and hence the outcome of the proposed model can be compared to such monitoring results. © 2015 by the Canadian Institute of Mining, Metallurgy & Petroleum and ISRM."
"12143775300;57198810433;","Numerical experiments of meso-α-scale precipitation systems under Baiu-front-like idealized environments",2015,"10.2151/sola.2015-034","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85037167657&doi=10.2151%2fsola.2015-034&partnerID=40&md5=31bbc43dc961cbe8685166a7095c2a34","To investigate the variability of the structure and evolution of meso-α-scale precipitation systems generated in the Baiu frontal zone, numerical experiments using a cloud-resolving non-hydrostatic model were performed with idealized Baiu-front-like environments. The environment was constructed based on hydrostatic and geostrophic balances, and temperature and relative humidity were designed by using Gaussian functions to realize the frontal structure and moist conveyor belt in the lower atmosphere. In order to generate meso-α-scale precipitation systems, temperature perturbation associated with a shallow depression was introduced. Long-lived band-shaped meso-α-scale precipitation systems with the internal multiscale structures as are often observed in the Baiu frontal zone were simulated under the given simplified environments. The variability of features of the meso-α-scale precipitation systems with respect to relative humidity in the middle troposphere in the Baiu frontal zone was examined as an example. The moister environment produced the more rainfall. Additionally, rainfall was intensified under a specific humidity condition. © 2015, the Meteorological Society of Japan."
"55713364700;56025123300;","Software engineering for scientific application: Effort report on the community land model within the earth system modeling framework",2014,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-84911888796&partnerID=40&md5=911979deb462e90aa1cd3b7ab14f7b54","One key factor in the improved understanding of earth system science is the development and improvement of high fidelity models. Along with the deeper understanding of earth system processes, the software complexity of those modelling systems becomes a barrier for further rapid model improvements and validation. In this paper, we present our experience on better understanding of the community land model (CLM) within an earth system modeling framework. After the science and software background of CLM, we represent three groups of CLM software engineering practices, which aim to 1) better understand the software system for rapid software system development on future computing platforms; 2) facilitate new model development via model-data comparison at field measurement level; 3) engage broad user communities via web services and cloud computing. Since better software engineering practices are much needed for general scientific software systems as we are adapting the integrated environmental modeling methodology, we hope those considerations can be beneficial to many other environmental modeling research programs involving multiscale system dynamics."
[No author id available],"International Workshop on Geoinformation Advances, GeoAdvances 2012",2013,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-85037059508&partnerID=40&md5=18b972f4eecf38a280d6ed76ec63e521","The proceedings contain 15 papers. The special focus in this conference is on Geoinformation Advances. The topics include: A review and conceptual framework for generalization of maps; Methods for georeferencing point cloud of building from static TLS: A review; CityGML for architectural heritage; Towards efficient putrajaya 3D SDI using schema-aware compressor for cityGML; Representing the dual of objects in a four-dimensional GIS; calibration and accuracy assessment of leica scanstation C10 terrestrial laser scanner; A methodology for processing raw LiDAR data to support urban flood modelling framework: Case study-Kuala Lumpur Malaysia; Potential of multiscale texture polarization ratio of C-band SAR for forest biomass estimation; reliability of a high accuracy image-based system for 3D modelling of the medial longitudinal arch during gait; WorldView-2 satellite imagery and airborne LiDAR data for object-based forest species classification in a cool temperate rainforest environment; unmanned aerial vehicle photogrammetric results using different real time kinematic global positioning system approaches; towards enhancing geometry textures of 3D city elements; preface."
"55425076500;7004923474;6508099535;","Global multiscale hydrologic web services",2012,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-84894195711&partnerID=40&md5=af49bf9d6d1d2c11cac1b4e096ac0ded","There are two problems slowing widespread adoption of spatially enabled hydrologic analysis, accessibility of data, and ease of use. This paper will describe and illustrate a system for sharing hydrologic analyses (geoprocessing) services and workflows that empowers GIS professionals, scientists, and citizens by making water data and its analysis accessible to a wide audience. The system leverages recent evolutions and standards in the information technology and GIS industries, particularly web services accessed through simple geospatial browser applications, cloud computing, and the increasing amount of elevation and hydrologic observations data. The GIS foundation of the system includes a high cartographic quality base map, an attributed vector hydrologic network, a hydrologically conditioned DEM, and linkage to temporal observation data. The system will provide a set of analytic services bound to best-available, authoritative data, and include tools and workflow documentation to enable others to more easily build similar systems. A key feature of the system is the development and serving of hydrologically conditioned elevation data at multiple scales. These datasets are the basis of geoprocessing services for interactive watershed delineation and flow tracing. Geoprocessing overlay services combine these areas with descriptive landscape information to explain or predict water quantity and quality. Extensive national and global datasets exist for land cover, soils, precipitation, and water observations, and are combined to provide hydrologic information in a highly accessible and interactive way. This system of web services is useful for GIS professional who may lack the time or skills needed to assemble and process all the needed data layers. But more importantly the system is critical to a large community of scientists, professionals, and citizens who want or need more detailed and useful water information in an easily accessible way."
"36238323500;","Linking the formation of molecular clouds and high-mass stars: A multitracer and multiscale study",2012,"10.1086/666496","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84863322332&doi=10.1086%2f666496&partnerID=40&md5=4d0b4a8d685e129ebd86b9358038fd06",[No abstract available]
"55242339000;55957630400;6505520345;","A three-scale domain decomposition method for the simulation of delamination and buckling interaction in composites",2011,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-84894149916&partnerID=40&md5=d50895503a5b8500af2b7aa7ed2607f7","A LaTIn-based mixed domain decomposition method for the study of the interactions between delaminations and buckling in composites is here presented. The need for the accurate prediction of the quasi-static response of industrial laminate plates requires using fine descriptions of the structure, especially when nonlinearities such as debonding and large displacements are involved. Hence, the computation of these structures results in very large numerical problems. In this paper, a nonlinear finite-element formulation together with a parallel iterative scheme is used for the computation of a 3D mesoscale model. The extension of the multiscale strategy to deal with both delamination and buckling is not straightforward, recent improvements to ensure the scalability of the method are presented. © Civil-Comp Press, 2011."
"15836894400;55665002100;","Parallel paradigm for ultraparallel multi-scale brain blood flow simulations",2011,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-84894131069&partnerID=40&md5=5b51a3cc9bf21b4b55d0be730d0dd693","We describe a computational framework for coupling an array of parallel numerical solvers, each designed to tackle a flow problem at different spatial and temporal scale. Specifically, we describe an architecture of the ultraparallel metasolver NεκTαrG for multiscale blood flow simulations. We focus on the multi-level communicating interface (MCI) which provides an efficient communication between hundreds of thousands of computer processors used by the solvers. Performance is evaluated using specifically designed benchmark problems and also a ""real-life"" simulation of a blood flow in the arterial network of the brain. © Civil-Comp Press, 2011."
"37006171300;57196403563;","Segmentation of trees and ground by multi-scale local density from airborne laser scanning data in forest areas",2010,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-84886684410&partnerID=40&md5=f2ad3e15efee7b09ec872f9b4fae950d","Airborne laser scanning technique has became a reliable and accurate means for fast acquisition the three dimensional data of the landscape. The generation of complex 3D models is time-consuming work with many manual adjustments, therefore it is important to study how different types of data processing methods could ease the work, ideally, it is desirable to automatically generate the 3D-models using laser data, different types of objects, such as buildings, trees, roads, etc. However, there are still some challenging difficulties in the interpretation of the data acquired, and the modeling of different objects is not automatically. This paper focus on the extraction of trees and ground from airborne laser scanning points in forest area, we proposed a new method based on the multi-scale local density algorithm to segment trees and ground points, our algorithm can be divided into three steps, they are multi-scale neighbor searching, filtering, multi-scale segmentation. In the multi-scale neighborhood searching phase, we use the ANN method presented by Songrit Manee et al to search neighborhood of each reference point. We project the 3D scanned points to the horizontal plan to generate the 2D neighbors of each reference point. The 3D neighbors of each point are generated by directly searching points with 3D information. The number of points in each neighbor is determined by the radius used in searching phase and this radius is called scale. The multi-scale neighborhoods are generated by changing the radius increasingly. In the filtering step, statistical analysis of height values of points in each scale neighborhood is carried out. We find that there would be a break point in the height histogram of the neighbors if there is a tree above the ground and the height break points hold in some continuous scales. This characteristic is the basis for the filtering process. In the multi-scale segmentation step, we can use the height break characteristic to filter the ground points from the data set. We label the height of points below height correspond to the break point as the ground points and points above the height as unlabeled ones. This step is very useful to avoid the effect of ground points. Our process won't stop until all the unlabeled points are segmented to the ground data set and tree data set. Our test result has shown that our method has robust performance in the condition of complicated tree objects."
"6507400558;7003704096;7005453346;6603561402;6603613067;","Tropical multiscale convective systems: Theory, modeling, and observations",2009,"10.1175/2008BAMS2565.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-65549111408&doi=10.1175%2f2008BAMS2565.1&partnerID=40&md5=fb4b1fbd4309730c1cde690e8775534e","A 5-day meeting was held at the University of Victoria in British Columbia Canada to further explain the behavior of the Madden Julian Oscillation (MJO). The MJO is poorly represented in contemporary general circulation models due to inadequacy of treatment across multiple spatial scales of the interaction of the associated hierarchy of organized structures. The event brought together 25 graduate students and post doctoral fellows from across North America with senior observationalists, theorists, and climate modelers. Topics that are included in the lecture and short course presentation are cloud microphysics, large-scale dynamics, internal waves, gravity currents and instabilities, convective organization, and global-scale dynamics."
"7004909806;6701561763;","A simple strategy for linearizing complex moist convective schemes",2009,"10.1002/qj.427","https://www.scopus.com/inward/record.uri?eid=2-s2.0-70149083901&doi=10.1002%2fqj.427&partnerID=40&md5=aa455f3d97dcb198ff88cdf936cc309f","Variational data assimilation methods and related applications depend on the validity of the tangent-linear approximation, which is truly challenging when applied to deep moist convection. A simple strategy for linearizing complex moist convective schemes in numerical weather prediction models is proposed. This strategy represents a trade-off between code development and maintenance on the one hand and expected benefit on the other hand. The generic linearized scheme described hereafter can be used in conjunction with any nonlinear moist convective scheme, thus eliminating the need to linearize complex codes. The universality of the scheme stems from the fact that conditional triggers and cloud vertical extent are supplied by the trajectory of the nonlinear scheme. In active columns, the convective tendencies cancel the largescale dynamical tendencies. Potential uses of the scheme include variational data assimilation and diagnostic studies such as tropical singular vectors and key analysis errors with precipitation. The relevance of the methodology is examined with the Global Environmental Multiscale model using the Kain-Fritsch mass-flux scheme that is operational at the Canadian Meteorological Centre. It is shown that the tangent-linear approximation is improved when compared to a linearized convection scheme having its own trigger functions. The improvement is particularly noticeable for the partition between stratiform and convective components of surface precipitation. Finally the examination of adjoint sensitivities of surface precipitation with the simplified linearized scheme triggered by the Kain-Fritsch scheme reveals a more pronounced sensitivity to midlatitude baroclinic instability and less predictability for tropical systems when compared to a Kuo-type scheme. Copyright © 2009 Royal Meteorological Society and Crown in the Right of Canada."
"6506131859;57198693222;7007108728;56000281400;6603734019;7004319487;","Goes sub-pixel analysis using AIRS-1.5 remote sensors",2004,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-2442503340&partnerID=40&md5=c5a33e774db7999d613bef1dfff90c5e","The Areal Vicinity Icing and Snow Advisor (AVISA), which is an experimental system for diagnosing and forecasting winter weather hazards for a given location, is discussed. The February 19 case shows that low level GOES/Global Environmental Multiscale (GEM) cloud tops heights can easily be contaminated by multi-layer clouds or instability from fronts. The comparison with vertically pointing X-band radar (VPR) reflectivity provides clues for determining when contamination is happening. AVISA attempts to combine sensors and model data to resolve different estimates of cloud top height."
"7003266200;6602378790;6701787960;6507667879;","Evaluation of predicted visual range using the community multiscale air quality modeling system",2000,"10.1016/s0021-8502(00)90055-7","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0034271339&doi=10.1016%2fs0021-8502%2800%2990055-7&partnerID=40&md5=1edaf13b5ec2c39e73638b12ba7f2b72","Simulations of visual range for locations in the eastern United States using Community Multiscale Air Quality (CMAQ) modelling system of EPA are compared with observed values. The model predicts the number, surface area, and species mass for particulate matter in atmosphere."