Author(s) ID,Title,Year,DOI,Link,Abstract
"7405763496;7003495982;13608035400;","A revised approach to ice microphysical processes for the bulk parameterization of clouds and precipitation",2004,"10.1175/1520-0493(2004)132<0103:ARATIM>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-1842587750&doi=10.1175%2f1520-0493%282004%29132%3c0103%3aARATIM%3e2.0.CO%3b2&partnerID=40&md5=8c0b474652c53d5041b5da9aa9a8c04d","A revised approach to cloud microphysical processes in a commonly used bulk microphysics parameterization and the importance of correctly representing properties of cloud ice are discussed. Several modifications are introduced to more realistically simulate some of the ice microphysical processes. In addition to the assumption that ice nuclei number concentration is a function of temperature, a new and separate assumption is developed in which ice crystal number concentration is a function of ice amount. Related changes in ice microphysics are introduced, and the impact of sedimentation of ice crystals is also investigated. In an idealized thunderstorm simulation, the distribution of simulated clouds and precipitation is sensitive to the assumptions in microphysical processes, whereas the impact of the sedimentation of cloud ice is small. Overall, the modifications introduced to microphysical processes play a role in significantly reducing cloud ice and increasing snow at colder temperatures and slightly increasing cloud ice and decreasing snow at warmer temperatures. A mesoscale simulation experiment for a heavy rainfall case indicates that impact due to the inclusion of sedimentation of cloud ice is not negligible but is still smaller than that due to the microphysics changes. Together with the sedimentation of ice, the new microphysics reveals a significant improvement in high-cloud amount, surface precipitation, and large-scale mean temperature through a better representation of the ice cloud-radiation feedback. © 2004 American Meteorological Society."
"57214576588;8701353900;15919465200;6603679007;6507439946;56228193100;","Operational convective-scale numerical weather prediction with the COSMO model: Description and sensitivities",2011,"10.1175/MWR-D-10-05013.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79960533068&doi=10.1175%2fMWR-D-10-05013.1&partnerID=40&md5=81d9f8400edeb870532121ad93fcaa5e","Since April 2007, the numerical weather prediction model, COSMO (Consortium for Small Scale Modelling), has been used operationally in a convection-permitting configuration, named COSMO-DE, at the Deutscher Wetterdienst (DWD; German weather service). Here the authors discuss the model changes that were necessary for the convective scale, and report on the experience from the first years of operational application of the model. For COSMO-DE the ability of the numerical solver to treat small-scale structures has been improved by using a Runge-Kutta method, which allows for the use of higher-order upwind advection schemes. The one-moment cloud microphysics parameterization has been extended by a graupel class, and adaptations for describing evaporation of rain and stratiform precipitation processes were made. Comparisons with a much more sophisticated two-moment scheme showed only minor differences in most cases with the exception of strong squall-line situations. Whereas the deep convection parameterization was switched off completely, small-scale shallow convection was still parameterized by the appropriate part of the Tiedtke scheme. During the first year of operational use, convective events in synoptically driven situations were satisfactorily simulated. Also the daily cycles of summertime 10-m wind and 1-h precipitation sums were well captured. However, it became evident that the boundary layer description had to be adapted to enhance convection initiation in airmass convection situations. Here the asymptotic Blackadar length scale l∞ had proven to be a sensitive parameter. © 2011 American Meteorological Society."
"7103158465;7202162685;6701324864;","A new double-moment microphysics parameterization for application in cloud and climate models. Part I: Description",2005,"10.1175/JAS3446.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-14744300799&doi=10.1175%2fJAS3446.1&partnerID=40&md5=3459942d755612dda75a95ce09d38316","A new double-moment bulk microphysics scheme predicting the number concentrations and mixing ratios of four hydrometeor species (droplets, cloud ice, rain, snow) is described. New physically based parameterizations are developed for simulating homogeneous and heterogeneous ice nucleation, droplet activation, and the spectral index (width) of the droplet size spectra. Two versions of the scheme are described: one for application in high-resolution cloud models and the other for simulating grid-scale cloudiness in larger-scale models. The versions differ in their treatment of the supersaturation field and droplet nucleation. For the high-resolution approach, droplet nucleation is calculated from Kohler theory applied to a distribution of aerosol that activates at a given supersaturation. The resolved supersaturation field and condensation/deposition rates are predicted using a semianalytic approximation to the three-phase (vapor, ice, liquid) supersaturation equation. For the large-scale version of the scheme, it is assumed that the supersaturation field is not resolved and thus droplet activation is parameterized as a function of the vertical velocity and diabatic cooling rate. The vertical velocity includes a subgrid component that is parameterized in terms of the eddy diffusivity and mixing length. Droplet condensation is calculated using a quasi-steady, saturation adjustment approach. Evaporation/deposition onto the other water species is given by nonsteady vapor diffusion allowing excess vapor density relative to ice saturation. © 2005 American Meteorological Society."
"7004134577;25953950400;7202619120;7202784114;","New RAMS cloud microphysics parameterization part I: the single-moment scheme",1995,"10.1016/0169-8095(94)00087-T","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029414242&doi=10.1016%2f0169-8095%2894%2900087-T&partnerID=40&md5=6703f25926863b4b5e1b3d6bd41672bd","A new cloud microphysical parameterization is described. Features of this new scheme include: the use of generalized gamma distributions as the basis function for all hydrometeor species; the use of a heat budget equation for hydrometeor classes, allowing heat storage and mixed phase hydrometeors; partitioning hydrometeors into seven classes (including separate graupel and hail categories); the use of stochastic collection rather than continuous accretion approximations and extension of the ice nucleation scheme to include homogeneous nucleation of ice from haze particles and cloud droplets. The versatility and credibility of the new scheme is explored, using sensitivity experiments for a simple two-dimensional convective cloud simulation. © 1995."
"7202619120;7004134577;7202784114;25953950400;","New RAMS cloud microphysics parameterization. Part II: The two-moment scheme",1997,"10.1016/S0169-8095(97)00018-5","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0031428710&doi=10.1016%2fS0169-8095%2897%2900018-5&partnerID=40&md5=f5daf40636d8ead5cce081c16ed2772c","This paper is the second in a series of articles describing the new microphysics scheme in the Regional Atmospheric Modeling System (RAMS). In this part, a new two-moment microphysical parameterization is described. The proposed scheme predicts the mixing ratio and number concentration of rain, pristine ice crystals, snow, aggregates, graupel and hail. The general gamma distribution is the basis function used for hydrometeor size in each category. Additional features include: use of stochastic collection for number concentration tendency; breakup of rain droplets formulated into the collection efficiency; diagnosis of ice crystal habit dependent on temperature and saturation; evaporation and melting of each species assuming that the smallest particles completely disappear first; and more complex shedding formulations which take into account the amount of water mass on the coalesced hydrometeor. Preliminary sensitivity testing of the new microphysical scheme in an idealized convective simulation shows that the two-moment prediction scheme allows more flexibility of the size distribution enabling the mean diameter to evolve in contrast to the one-moment scheme. Sensitivity to the prescribed input parameters such as cloud droplet concentrations and the shape parameter ν is demonstrated in the model results. © 1997 Elsevier Science B.V."
"9239331500;7006864972;","A multimoment bulk microphysics parameterization. Part I: Analysis of the role of the spectral shape parameter",2005,"10.1175/JAS3534.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-27744577273&doi=10.1175%2fJAS3534.1&partnerID=40&md5=9e721478ce704f4c4b52a92979311e88","With increasing computer power, explicit microphysics schemes are becoming increasingly important in atmospheric models. Many schemes have followed the approach of Kessler in which one moment of the hydrometeor size distribution, proportional to the mass content, is predicted. More recently, the two-moment method has been introduced in which both the mass and the total number concentration of the hydrometeor categories are independently predicted. In bulk schemes, the size spectrum of each hydrometeor category is often described by a three-parameter gamma distribution function, N(D) = N0Dαe-λD. Two-moment schemes generally treat N0 and λ as prognostic parameters while holding α constant. In this paper, the role of the spectral shape parameter, α, is investigated by examining its effects on sedimentation and microphysical growth rates. An approach is introduced for a two-moment scheme where α is allowed to vary diagnostically as a function of the mean-mass diameter. Comparisons are made between calculations using various bulk approaches - a one-moment, a two-moment, and a three-moment method - and an analytic bin model. It is found that the size-sorting mechanism, which exists in a bulk scheme when different fall velocities are applied to advect the different predicted moments, is significantly different amongst the schemes. The shape parameter plays an important role in determining the rate of size sorting. Likewise, instantaneous growth rates related to the moments are shown to be significantly affected by this parameter. © 2005 American Meteorological Society."
"8701353900;6603340224;","A two-moment cloud microphysics parameterization for mixed-phase clouds. Part 1: Model description",2006,"10.1007/s00703-005-0112-4","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33244472609&doi=10.1007%2fs00703-005-0112-4&partnerID=40&md5=4bcae7c981a5541a959d369fbf743999","A two-moment microphysical parameterization for mixed-phase clouds was developed to improve the explicit representation of clouds and precipitation in mesoscale atmospheric models. The scheme predicts the evolution of mass as well as number densities of the five hydrometeor types cloud droplets, raindrops, cloud ice, snow and graupel. Since the number concentrations of all these hydrometeors are calculated explicitly, all relevant homogenous and heterogenous nucleation processes have been parameterized including the activation of cloud condensation nuclei, which is not predicted in most state-of-the-art cloud resolving models. Therefore the new scheme can discriminate between continental and maritime conditions and can be used for investigations of aerosol effects on the precipitation formation in mixed-phase clouds. In addition, the scheme includes turbulence effects on droplet coalescence, collisional breakup of raindrops and size-dependent collision efficiencies. A new general approximation of the collection kernels and the corresponding collision integrals is introduced. © Springer-Verlag 2005."
"9239331500;7006864972;","A multimoment bulk microphysics parameterization. Part II: A proposed three-moment closure and scheme description",2005,"10.1175/JAS3535.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-27744444728&doi=10.1175%2fJAS3535.1&partnerID=40&md5=5e740b12e56a975a1be1f72e579db579","Many two-moment bulk schemes use a three-parameter gamma distribution of the form N(D) = N0Dαe-λD to describe the size spectrum of a given hydrometeor category. These schemes predict changes to the ass content and the total number concentration thereby allowing N0 and λ to vary as prognostic parameters while fixing the shape parameter, α. As was shown in Part I of this study, the shape parameter, which represents the relative dispersion of the hydrometeor size spectrum, plays an important role in the computation of sedimentation and instantaneous growth rates in bulk microphysics schemes. Significant improvement was shown by allowing α to vary as a diagnostic function of the predicted moments rather than using a fixed-value approach. Ideally, however, α should be an independent prognostic parameter. In this paper, a closure formulation is developed for calculating the source and sink terms of a third moment of the size distribution - the radar reflectivity. With predictive equations for the mass content, total number concentration, and radar reflectivity, α becomes a fully prognostic variable and a three-moment parameterization becomes feasible. A new bulk microphysics scheme is presented and described. The full version of the scheme predicts three moments for all precipitating hydrometeor categories. Simulations of an idealized hailstorm in the context of a 1D kinematic cloud model employing the one-moment, two-moment, and three-moment versions of the scheme are compared. The vertical distribution of the hydrometeor mass contents using the two-moment version with diagnostic-α relations are much closer to the three-moment than the one-moment simulation. However, the evolution of the surface precipitation rate is notably different between the three-moment and two-moment schemes. © 2005 American Meteorological Society."
"7005212820;7202208382;7005461477;","Liquid and ice cloud microphysics in the CSU general circulation model. Part I: Model description and simulated microphysical processes",1996,"10.1175/1520-0442(1996)009<0489:LAICMI>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029774487&doi=10.1175%2f1520-0442%281996%29009%3c0489%3aLAICMI%3e2.0.CO%3b2&partnerID=40&md5=8ea06fd6acf05ffc02c90fce3ce3daff","Microphysical processes responsible for the formation and dissipation of water and ice clouds have been incorporated into the Colorado State University General Circulation Model in order to 1) yield a more physically based representation of the components of the atmospheric moisture budget, 2) link the distribution and optical properties of the model-generated clouds to the predicted cloud water and ice amounts, and 3) produce more realistic simulations of cloudiness and the earth's radiation budget. The bulk cloud microphysics scheme encompasses five prognostic variables for the mass of water vapor, cloud water, cloud ice, rain, and snow. Graupel and hail are neglected. Cloud water and cloud ice are predicted to form through large-scale condensation and deposition processes and also through detrainment at the tops of cumulus towers. The production of rain and snow occur through autoconversion of cloud water and cloud ice. Rain drops falling through clouds can grow by collecting cloud water, and falling snow can collect both cloud water and cloud ice. These collection processes are formulated using the continuous collection equation. Evaporation of cloud water, cloud ice, rain, and snow are allowed in subsaturated layers. Melting and freezing are included. We also provide a coupling between convective clouds and stratiform anvils through the detrainment of cloud water and cloud ice at the tops of cumulus towers. Interactive cloud optical properties provide the link between the cloud microphysics and radiation parameterizations; the optical depths and infrared emissivities of large-scale stratiform clouds are parameterized in terms of the cloud water and cloud ice paths. Two annual-cycle numerical simulations are performed to assess the impact of cloud microphysics on the hydrological cycle. In the ""EAULIQ"" run, large-scale moist processes and cloud optical properties are driven by the bulk cloud microphysics parameterization. In the ""CONTROL"" run, condensed water is immediately removed from the atmosphere in the form of rain, which may evaporate as it falls through subsaturated layers. Stratiform ice clouds are not considered in CONTROL. When clouds are present, cloud optical depths and cloud infrared emissivities are dependent on the mean cloud temperatures. Results are presented in terms of January and July monthly averages. Emphasis is placed on the spatial distributions of cloud water, cloud ice, rain, and snow produced by the cloud microphysics scheme. In EAULIQ, cloud water and cloud ice are more abundant in the middle latitudes than in the Tropics, suggesting that large-scale condensation contributes a major part to the production of condensed water. Comparisons between the simulated vertically integrated cloud water and the columnar cloud water retrievals from satellite microwave measurements over the global oceans indicate a reasonable agreement. Interactions between the cloud microphysics and cumulus convection parameterizations lead to smaller, more realistic precipitation rates. In particular, the cumulus precipitation rate is strongly reduced when compared to CONTROL."
"7103119050;55087038900;7102018821;6506933473;","Improvements of an ice-phase microphysics parameterization for use in numerical simulations of tropical convection",1995,"10.1175/1520-0450-34.1.281","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029104142&doi=10.1175%2f1520-0450-34.1.281&partnerID=40&md5=daa4370505d05a82293ce6e9245dac39","It is important to properly simulate the extent and ice water content of tropical anvil clouds in numerical models that explicitly include cloud formation because of the significant effects that these clouds have on the radiation budget. For this reason, a commonly used bulk ice-phase microphysics parameterization was modified to more realistically simulate some of the microphysical processes that occur in tropical anvil clouds. Cloud ice growth by the Bergeron process and the associated formation of snow were revised. The characteristics of graupel were also modified in accord with a previous study. Numerical simulations of a tropical squall line demonstrate that the amount of cloud ice and the extent of anvil clouds are increased to more realistic values by the first two changes. (Authors)"
"7006270084;7003666669;36538539800;7003777379;7101909551;7004575544;6602973136;7202048112;7103023423;6603268269;","MIRAGE: Model description and evaluation of aerosols and trace gases",2004,"10.1029/2004JD004571","https://www.scopus.com/inward/record.uri?eid=2-s2.0-19944426337&doi=10.1029%2f2004JD004571&partnerID=40&md5=9cd1f53e411baa2b5b8b2cf41a1a918e","The Model for Integrated Research on Atmospheric Global Exchanges (MIRAGE) modeling system, designed to study the impacts of anthropogenic aerosols on the global environment, is described. MIRAGE consists of a chemical transport model coupled online with a global climate model. The chemical transport model simulates trace gases, aerosol number, and aerosol chemical component mass (sulfate, methane sulfonic acid (MSA), organic matter, black carbon (BC), sea salt, and mineral dust) for four aerosol modes (Aitken, accumulation, coarse sea salt, and coarse mineral dust) using the modal aerosol dynamics approach. Cloud-phase and interstitial aerosol are predicted separately. The climate model, based on Community Climate Model, Version 2 (CCM2), has physically based treatments of aerosol direct and indirect forcing. Stratiform cloud water and droplet number are simulated using a bulk microphysics parameterization that includes aerosol activation. Aerosol and trace gas species simulated by MIRAGE are presented and evaluated using surface and aircraft measurements. Surface-level SO2 in North American and European source regions is higher than observed. SO 2 above the boundary layer is in better agreement with observations, and surface-level SO2 at marine locations is somewhat lower than observed. Comparison with other models suggests insufficient SO2 dry deposition; increasing the deposition velocity improves simulated SO2. Surface-level sulfate in North American and European source regions is in good agreement with observations, although the seasonal cycle in Europe is stronger than observed. Surface-level sulfate at high-latitude and marine locations, and sulfate above the boundary layer, are higher than observed. This is attributed primarily to insufficient wet removal; increasing the wet removal improves simulated sulfate at remote locations and aloft. Because of the high sulfate bias, radiative forcing estimates for anthropogenic sulfur given in 2001 by S. J. Ghan and colleagues are probably too high. Surface-level dimethyl sulfide (DMS) is ∼40% higher than observed, and the seasonal cycle shows mo much DMS in local winter, partially caused by neglect of oxidation by NO3. Surface-level MSA at marine locations is ∼80% higher than observed, also attributed to insufficient wet removal. Surface-level BC is ∼ 50% lower than observed in the United States and ∼40% lower than observed globally. Treating BC as initially hydrophobic would lessen this bias. Surface-level organic matter is lower than observed in the United States, similar to BC, but shows no bias in the global comparison. Surface-level sea salt concentrations are ∼30% lower than observed, partly caused by low temporal variance of the model's 10 m wind speeds. Submicrometer sea salt is strongly underestimated by the emissions parameterization. Dust concentrations are within a factor of 3 at most sites but tend to be lower than observed, primarily because of neglect of very large particles and underestimation of emissions and vertical transport under high-wind conditions. Accumulation and Aitken mode number concentrations and mean sizes at the surface over ocean, and condensation nuclei concentrations aloft over the Pacific, are in fair agreement with observations. Concentrations over land are generally higher than observations, with mean sizes correspondingly lower than observations, especially at some European locations. Increasing the assumed size of emitted particles produces better agreement at the surface over land, and reducing the particle nucleation rate improves the agreement aloft over land. Copyright 2004 by the American Geophysical Union."
"8511991900;57200702127;7102084129;55717074000;","Review of aerosol-cloud interactions: Mechanisms, significance, and challenges",2016,"10.1175/JAS-D-16-0037.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84994128820&doi=10.1175%2fJAS-D-16-0037.1&partnerID=40&md5=dd9192fd64bbcb582393bfd509b2efa5","Over the past decade, the number of studies that investigate aerosol-cloud interactions has increased considerably. Although tremendous progress has been made to improve the understanding of basic physical mechanisms of aerosol-cloud interactions and reduce their uncertainties in climate forcing, there is still poor understanding of 1) some of the mechanisms that interact with each other over multiple spatial and temporal scales, 2) the feedbacks between microphysical and dynamical processes and between local-scale processes and large-scale circulations, and 3) the significance of cloud-aerosol interactions on weather systems as well as regional and global climate. This review focuses on recent theoretical studies and important mechanisms on aerosol-cloud interactions and discusses the significances of aerosol impacts on radiative forcing and precipitation extremes associated with different cloud systems. The authors summarize the main obstacles preventing the science from making a leap-for example, the lack of concurrent profile measurements of cloud dynamics, microphysics, and aerosols over a wide region on the observation side and the large variability of cloud microphysics parameterizations resulting in a large spread of modeling results on the modeling side. Therefore, large efforts are needed to escalate understanding. Future directions should focus on obtaining concurrent measurements of aerosol properties and cloud microphysical and dynamic properties over a range of temporal and spatial scales collected over typical climate regimes and closure studies, as well as improving understanding and parameterizations of cloud microphysics such as ice nucleation, mixed-phase properties, and hydrometeor size and fall speed. © 2016 American Meteorological Society."
"8701353900;6603340224;","A two-moment cloud microphysics parameterization for mixed-phase clouds. Part 2: Maritime vs. continental deep convective storms",2006,"10.1007/s00703-005-0113-3","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33244491917&doi=10.1007%2fs00703-005-0113-3&partnerID=40&md5=4871cfb4b9e575f0ee7f37aac15923ec","A systematic modeling study investigates the effects of cloud condensation nuclei (CCNs) on the evolution of mixed-phase deep convective storms. Following previous studies the environmental conditions like buoyancy and vertical wind shear are varied to simulate different storm types like ordinary single cells, multicells and supercells. In addition, the CCN characteristics are changed from maritime to continental conditions. The results reveal very different effects of continentality on the cloud microphysics and dynamics of the different storms. While a negative feedback on total precipitation and maximum updraft velocity is found for ordinary single cells and supercell storms, a positive feedback exists for multicell cloud systems. The most important link between CCN properties, microphysics and dynamics is the release of latent heat of freezing. © Springer-Verlag 2005."
"57193882808;","Toward cloud resolving modeling of large-scale tropical circulations: A simple cloud microphysics parameterization",1998,"10.1175/1520-0469(1998)055<3283:TCRMOL>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033232464&doi=10.1175%2f1520-0469%281998%29055%3c3283%3aTCRMOL%3e2.0.CO%3b2&partnerID=40&md5=4a72dba4eb71dd1abd8c3df76c9ef780","This paper discusses cloud microphysical essential for large-scale tropical circulation and the tropical climate, as well as the strategy to include them in large-scale modelsi that resolve cloud dynamics. The emphasis is on the ice microphysics, which traditional cloud models consider in a fair complex manner and where a simplified approach is desirable. An extension of the classical warm rain bulk parameterization is presented. The proposed scheme retains simplicity of the warm rain parameterization (e.g., only two classes of condensed water are considered) but introduces two important modifications for temperatures well below freezing: 1) the saturation conditions are prescribed based on saturation with respect to ice, not water; and 2) growth characteristics and terminal velocities of precipition particles are representative for ice particle, not raindrops. Numerical tests suggest that, despite its simplicity, the parametrization is able to capture essential aspects of the cloud microphsics important for the interaction between convection and large-scale evironment. As an example of the application of this parameterization, preliminary results of the two-dimensional cloud-resoulving simulation of a Walker-like circulation are presented."
"55545601500;8258673100;7403282069;35779178900;56158622800;7403508241;35263384600;25928347900;","Occurrence, liquid water content, and fraction of supercooled water clouds from combined CALIOP/IIR/MODIS measurements",2010,"10.1029/2009JD012384","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77958185165&doi=10.1029%2f2009JD012384&partnerID=40&md5=b0e69c49c948acae1375a2e39ddb4473","The CALIOP depolarization measurements, combined with backscatter intensity measurements, are effective in discriminating between water clouds and ice clouds. The same depolarization measurements can also be used for estimating liquid water content information. Using cloud temperature information from the collocated infrared imaging radiometer measurements and cloud water paths from collocated MODIS measurements, this study compiles global statistics of the occurrence frequency, liquid water content, liquid water path, and their temperature dependence. For clouds with temperatures between -40°C and 0°C, the liquid phase fractions and liquid water paths are significantly higher than the ones from previous studies using passive remote sensing measurements. At midlatitudes, the occurrence of liquid phase clouds at temperatures between -40°C and 0°C depends jointly on both cloud height and cloud temperature. At high latitudes, more than 95% of low-level clouds with temperatures between -40°C and 0°C are water clouds. Supercooled water clouds are mostly observed over ocean near the storm-track regions and high-latitude regions. Supercooled water clouds over land are observed in the Northern Hemisphere over Europe, East Asia, and North America, and these are the supercooled water clouds with highest liquid water contents. The liquid water content of all supercooled water clouds is characterized by a Gamma (Γ) distribution. The mode values of liquid water content are around 0.06 g/m 3 and are independent of cloud temperature. For temperatures warmer than -15°C, mean value of the liquid water content is around 0.14 g/m 3. As the temperature decreases, the mean cloud liquid water content also decreases. These results will benefit cloud models and cloud parameterizations used in climate models in improving their ice-phase microphysics parameterizations and the aviation hazard forecast."
"7402379980;7102080550;9239331500;7006864972;","Comparison of evaporation and cold pool development between single-moment and multimoment bulk microphysics schemes in idealized simulations of tornadic thunderstorms",2010,"10.1175/2009MWR2956.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77953029093&doi=10.1175%2f2009MWR2956.1&partnerID=40&md5=1280d70deb3a72ff8139da370d7d87f8","Idealized simulations of the 3 May 1999 Oklahoma tornadic supercell storms are conducted at various horizontal grid spacings ranging from 1km to 250 m, using a sounding extracted from a prior 3-km grid spacing real-data simulation. A sophisticated multimoment bulk microphysics parameterization scheme capable of predicting up to three moments of the particle or drop size distribution (DSD) for several liquid and ice hydrometeor species is evaluated and compared with traditional single-moment schemes. The emphasis is placed on the impact of microphysics, specifically rain evaporation and size sorting, on cold pool strength and structure, and on the overall reflectivity structure of the simulated storms. It is shown through microphysics budget analyses and examination of specific processes within the low-level downdraft regions that the multimoment scheme has important advantages, which lead to a weaker and smaller cold pool and better reflectivity structure, particularly in the forward-flank region of the simulated supercells. Specifically, the improved treatment of evaporation and size sorting, and their effects on the predicted rain DSDs by the multimoment scheme helps to control the cold bias often found in the simulations using typical single-moment schemes. The multimoment results are more consistent with observed (from both fixed and mobile mesonet platforms) thermodynamic conditions within the cold pools of the discrete supercells of the 3 May 1999 outbreak. © 2010 American Meteorological Society."
"7403282069;7202208382;","Explicit simulation of cumulus ensembles with the GATE Phase III data: Comparison with observations",1996,"10.1175/1520-0469(1996)053<3710:ESOCEW>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0030324233&doi=10.1175%2f1520-0469%281996%29053%3c3710%3aESOCEW%3e2.0.CO%3b2&partnerID=40&md5=a29d065526a70622052f8337a7ffe989","The macroscopic behavior of cumulus convection and its mesoscale organization during Phase III of the Global Atmospheric Research Program's (GARP) Atlantic Tropical Experiment (GATE) is simulated with a two-dimensional (2D) cloud ensemble model. The model includes a three-phase bulk microphysics parameterization, a third-moment turbulence closure and an interactive, radiative transfer parameterization. The observed large-scale, horizontal advective effects and large-scale vertical velocity are imposed on the model's thermodynamic equations uniformly in the horizontal. The simulated, domain-averaged horizontal wind components are nudged toward the observed winds. A detailed comparison with available observations is made in this study. The observed time variations of the surface precipitation rate, surface evaporation rate, outgoing longwave radiation flux, and the vertical distributions of temperature, water vapor mixing ratio, and relative humidity are successfully reproduced by the model, as well as the vertical structure and time evolution of major convective systems. The most significant result is that the model is able to reproduce the negative correlation between the intensity of convection and the convective available potential energy. The simulated total cloud amount compares favorably with the whole-sky camera observations of Holle et al., but the low-level cloud amount is significantly underestimated. In spite of its success, sensitivity tests suggest that the 2D model has stronger inhibiting effects on convection and is more efficient in vertical transports than is observed when the vertical wind shear is strong. The CEM also produces smaller amplitudes of the daily fluctuations in cloud amount and precipitable water than observed, due possibly to the shortcomings of the microphysics parameterization."
"7005742394;6603340224;7005729142;35572096100;35607774000;7003886299;7103213900;7101752236;57192174561;7004559579;6505932008;35572026100;","Representation of microphysical processes in cloud-resolving models: Spectral (bin) microphysics versus bulk parameterization",2015,"10.1002/2014RG000468","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84937438125&doi=10.1002%2f2014RG000468&partnerID=40&md5=010c740ed839b4a592563d2dd978b75c","Most atmospheric motions of different spatial scales and precipitation are closely related to phase transitions in clouds. The continuously increasing resolution of large-scale and mesoscale atmospheric models makes it feasible to treat the evolution of individual clouds. The explicit treatment of clouds requires the simulation of cloud microphysics. Two main approaches describing cloud microphysical properties and processes have been developed in the past four and a half decades: bulk microphysics parameterization and spectral (bin) microphysics (SBM). The development and utilization of both represent an important step forward in cloud modeling. This study presents a detailed survey of the physical basis and the applications of both bulk microphysics parameterization and SBM. The results obtained from simulations of a wide range of atmospheric phenomena, from tropical cyclones through Arctic clouds using these two approaches are compared. Advantages and disadvantages, as well as lines of future development for these methods are discussed. Key Points Review of concepts of microphysical methods Analysis of errors in representation of microphysical processes Comparison of results obtained by different methods ©2015. American Geophysical Union. All Rights Reserved."
"55087038900;7103119050;7102018821;","Interactions of radiation and convection in simulated tropical cloud clusters",1995,"10.1175/1520-0469(1995)052<1310:ioraci>2.0.co;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029503698&doi=10.1175%2f1520-0469%281995%29052%3c1310%3aioraci%3e2.0.co%3b2&partnerID=40&md5=28a42559416fe017c72d873ca009e108","A two-dimensional cumulus ensemble model is used to study the interactions of radiation and convection in tropical squall cloud clusters. The model includes cloud-scale and mesoscale dynamics, an improved bulk ice microphysics parameterization, and an advanced interactive radiative transfer scheme. The life cycle of a tropical squall line is simulated over a 12-h period using thermodynamic and kinematic initial conditions as well as large-scale advective forcing typical of a GATE Phase III squall cluster environment. The focus is on the interaction and feedback between longwave (or IR) radiation and cloud processes. -from Authors"
"7601492669;","An explicit simulation of tropical cyclones with a triply nested movable mesh primitive equation model: TCM3. Part II: Model refinements and sensitivity to cloud microphysics parameterization",2002,"10.1175/1520-0493(2002)130<3022:AESOTC>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036965890&doi=10.1175%2f1520-0493%282002%29130%3c3022%3aAESOTC%3e2.0.CO%3b2&partnerID=40&md5=943fd42732c3be236f3a1e6197bf945f","It has been long known that cloud microphysics can have a significant impact on the simulations of precipitation; however, there have been few studies so far that have investigated the effect of cloud microphysics on tropical cyclones. In the most advanced simulation of tropical cyclones by numerical models, the use of explicit cloud microphysics becomes more and more attractive with cumulus parameterization by passed at very high resolutions. In this study, the sensitivity of the simulated tropical cyclone structure and intensity to the choice and details of cloud microphysics parameterization is investigated using the triply nested movable mesh tropical cyclone model TCM3 described in Part I but with several refinements. Three different cloud microphysics parameterization schemes are tested, including the warm-rain-only cloud microphysics scheme (WMRN) and two mixed-ice-phase cloud microphysics schemes, one of which has three ice species (cloud ice-snow-graupel: CTRL) while the other has hail instead of graupel (HAIL). It is shown that, although the cloud structures of the simulated tropical cyclone can be quite different with different cloud microphysics schemes, intensification rate and final intensity are not very sensitive to the details of the cloud microphysics parameterizations. This occurs because all of the schemes produce similar vertical heating profiles and similar levels of rainbands, stratiform clouds, and downdrafts. The latter are found to be prohibitive factors to tropical cyclone intensification and intensity. Both evaporation of rain and melting of snow and graupel are responsible for the generation of downdrafts and rainbands. This is demonstrated using two extra experiments in which the evaporation of rain and melting of snow and graupel are removed from WMRN or CTRL experiments. In these two extreme cases, neither significant rainbands nor downdrafts were generated. As a result, the storm developed much more rapidly and reached an intensity that was much stronger than those in the experiments with both evaporation of rain and melting of ice species. In comparison with the substantial sensitivity of simulated tropical cyclones to different cumulus parameterization schemes found in previous studies, the weak sensitivity of the simulated tropical cyclone intensity to cloud microphysics parameterizations from this study indicates the potential advantage in using explicit cloud microphysics in tropical cyclone models to improve the intensity forecasting."
"7409792174;35364149600;7403077486;7201888941;7003495982;","High-resolution simulations of wintertime precipitation in the Colorado headwaters region: Sensitivity to physics parameterizations",2011,"10.1175/MWR-D-11-00009.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84862907703&doi=10.1175%2fMWR-D-11-00009.1&partnerID=40&md5=d9e36132429dd3967c6216b2f479ddc7","An investigation was conducted on the effects of various physics parameterizations on wintertime precipitation predictions using a high-resolution regional climate model. The objective was to evaluate the sensitivity of cold-season mountainous snowfall to cloud microphysics schemes, planetary boundary layer (PBL) schemes, land surface schemes, and radiative transfer schemes at a 4-km grid spacing applicable to the next generation of regional climate models. The results indicated that orographically enhanced precipitation was highly sensitive to cloud microphysics parameterizations. Of the tested 7 parameterizations, 2 schemes clearly outperformed the others that overpredicted the snowfall amount by asmuch as;30%-60% on the basis of snowtelemetry observations. Significant differences among these schemes were apparent in domain averages, spatial distributions of hydrometeors, latent heating profiles, and cloud fields. In comparison, model results showed relatively weak dependency on the land surface, PBL, and radiation schemes, roughly in the order of decreasing level of sensitivity. © 2011 American Meteorological Society."
"7003926380;7004198777;7101899854;6603372665;6603768446;8519022900;7005485117;35203432500;56157800800;7101675442;7103294028;7102962393;7003283811;7005729142;7004814501;57198363065;7003729315;6602638061;7202715936;7006874359;35263854800;7006510465;35396858200;","The Saharan air layer and the fate of African easterly waves: NASA's AMMA field study of tropical cyclogenesis",2009,"10.1175/2009BAMS2728.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-70450189629&doi=10.1175%2f2009BAMS2728.1&partnerID=40&md5=79be7fe87210358a8dd1688123e33475","National Aeronautics and Space Administration's (NASA) African Monsoon Multidisciplinary Analysis (AMMA), NAMMA, is a large international project that aims to improve the understanding of the West African monsoon, especially the African easterly waves (AEW). The project also aims to gain an improved understanding of the linkage between AEWs, the Saharan air layer (SAL), and tropical cyclogenesis. The seven AEWs sampled during the NAMMA field campaign has represented the best validation database ever obtained in the eastern North Atlantic, providing an opportunity to evaluate the latest remote sensing retrieval algorithms, and dynamics and microphysics parameterizations used in numerical models. It also gives an insight into how weak disturbances intensify and the role played by the structure and evolution of the SAL, with main development area for tropical cyclones in the Atlantic basin."
"7201687375;35569011300;9233435600;57199389293;7201356364;7003890696;","Development of a coupled groundwater-atmosphere model",2011,"10.1175/2010MWR3392.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79951649712&doi=10.1175%2f2010MWR3392.1&partnerID=40&md5=b1cd208750a9c7468ccb34834aa1de8a","Complete models of the hydrologic cycle have gained recent attention as research has shown interdependence between the coupled land and energy balance of the subsurface, land surface, and lower atmosphere. PF.WRF is a new model that is a combination of the Weather Research and Forecasting (WRF) atmospheric model and a parallel hydrology model (ParFlow) that fully integrates three-dimensional, variably saturated subsurface flow with overland flow. These models are coupled in an explicit, operator-splitting manner via the Noah land surface model (LSM). Here, the coupled model formulation and equations are presented and a balance of water between the subsurface, land surface, and atmosphere is verified. The improvement in important physical processes afforded by the coupled model using a number of semi-idealized simulations over the Little Washita watershed in the southernGreat Plains is demonstrated. These simulations are initialized with a set of offline spinups to achieve a balanced state of initial conditions. To quantify the significance of subsurface physics, comparedwith other physical processes calculated inWRF, these simulations are carried out with two different surface spinups and three different microphysics parameterizations inWRF. These simulations illustrate enhancements to coupled model physics for two applications: water resources and wind-energy forecasting. For the water resources example, it is demonstrated how PF.WRF simulates explicit rainfall and water storage within the basin and runoff. Then the hydrographs predicted by different microphysics schemes withinWRF are compared. Because soil moisture is expected to impact boundary layer winds, the applicability of the model to wind-energy applications is demonstrated by using PF.WRF and WRF simulations to provide estimates of wind and wind shear that are useful indicators of wind-power output. © 2011 American Meteorological Society."
"22980035400;7006446865;","The impact of size sorting on the polarimetric radar variables",2012,"10.1175/JAS-D-11-0125.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84864844233&doi=10.1175%2fJAS-D-11-0125.1&partnerID=40&md5=cc6d88bcaea3c42135ce79505021af8f","Differential sedimentation of precipitation occurs because heavier hydrometeors fall faster than lighter ones. Updrafts and vertical wind shear can maintain this otherwise transient size sorting, resulting in prolonged regions of ongoing particle sorting in storms. This study quantifies the impact of size sorting on the S-band polarimetric radar variables (radar reflectivity factor at horizontal polarization Z H, differential reflectivity Z DR, specific differential phase K DP, and the copolar cross-correlation coefficient phv). These variables are calculated from output of two idealized bin models: a one-dimensional model of pure raindrop fallout and a two-dimensional rain shaft encountering vertical wind shear. Additionally, errors in the radar variables as simulated by single-, double-, and triple-moment bulk microphysics parameterizations are quantified for the same size sorting scenarios. Size sorting produces regions of sparsely concentrated large drops with a lack of smaller drops, causing Z DR enhancements as large as 1 dB in areas of decreased Z H, often along a Z H gradient. Such areas of enhanced Z DR are offset from those of high Z H and K DP. Illustrative examples of polarimetric radar observations in a variety of precipitation regimes demonstrate the widespread occurrence of size sorting and are consistent with the bin model simulations. Single-moment schemes are incapable of size sorting, leading to large underestimations in Z DR (&gt;2 dB) compared to the bin model solution. Double-moment schemes with a fixed spectral shape parameter produce excessive size sorting by incorrectly increasing the number of large raindrops, overestimating Z DR by 2-3 dB. Three-moment schemes with variable shape parameters better capture the narrowing drop size distribution resulting from size sorting but can underestimate Z DR and overestimate K DP by as much as 20%. Implications for polarimetric radar data assimilation into storm-scale numerical weather prediction models are discussed. © 2012 American Meteorological Society."
"7003495982;7405763496;26532919500;","A new method for representing mixed-phase particle fall speeds in bulk microphysics parameterizations",2008,"10.2151/jmsj.86A.33","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77149148650&doi=10.2151%2fjmsj.86A.33&partnerID=40&md5=78830779350c24c2f4f8edef37d5dc12","Here we present a simple method of improving bulk mixed-phase microphysical schemes to allow for a more realistic representation of partially rimed particles. The new procedure unifies the snow and graupel particles by assigning a single fal lspeed to both that is weighted by the mixing ratios, and applying that fall speed to both sedimentation and accretion processes. This avoids the problem of the species separating out by sedimentation as graupel forms, and the further problem of graupel then accreting snow too quickly because of its high relative fall speed. Instead the unified graupel/snow moves together and evolves in its relative ratio due to riming, behaving as intermediate or partially rimed particles. Tests of the new method were carried out using the Weather Research and Forecasting (WRF) Single- Moment 6-class (WSM6) microphysics scheme in a high-resolution idealized simulation, and mesoscale heavy precipitation events in the summer and winter over Korea. The effect of the new accretion rates on cloud structure and precipitation was found to be greater than that of the changed sedimentation alone. Verification of these tests showed a much-reduced production of graupel and more snow, influencing the cloud structure and surface precipitation fields. The scheme shows promise in improving precipitation intensity and precipitation type forecasts. © 2008, Meteorological Society of Japan."
"57201725986;7006329926;7401559815;","Dominant cloud microphysical processes in a tropical oceanic convective system: A 2D cloud resolving modeling study",2002,"10.1175/1520-0493(2002)130<2481:DCMPIA>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036795433&doi=10.1175%2f1520-0493%282002%29130%3c2481%3aDCMPIA%3e2.0.CO%3b2&partnerID=40&md5=6efe768a0b354b22c56b7d22a57d7c9f","Dominant cloud microphysical processes associated with a tropical oceanic convective system are investigated based on a 2D cloud resolving simulation. The model is forced by the zonal-mean vertical velocity, zonal wind, sea surface temperature, and horizontal temperature and moisture advections measured and derived from the TOGA COARE period. The analysis of cloud microphysics budgets shows that cloud water forms due to vapor condensation, but most of the conversion of cloud water to precipitation occurs primarily through two mechanisms, depending on the temperature when they occur: through riming of cloud water onto precipitation ice (snow or graupel) at colder than 0°C and collection of cloud water by rain at warmer temperatures. Processes involving the liquid phase are dominant during the early stages of convection development. The collection process produces rain, and the riming process enhances ice clouds. Ice processes are more dominant during the later stages. The melting of precipitation ice and vapor deposition become important in producing rain and ice clouds, respectively. Based on the analysis of dominant cloud microphysical processes, a simplified set of cloud microphysics parameterization schemes are proposed. Simulations with the simplified and original sets show similar thermodynamic evolution and cloud properties."
"7005869171;6603381720;","A bulk microphysics parameterization with multiple ice precipitation categories",2005,"10.1175/JAM2211.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-19144362100&doi=10.1175%2fJAM2211.1&partnerID=40&md5=65c32cd2ffffba94dbf1a24bad7769e9","A single-moment bulk microphysics scheme with multiple ice precipitation categories is described. It has 2 liquid hydrometeor categories (cloud droplets and rain) and 10 ice categories that are characterized by habit, size, and density-two ice crystal habits (column and plate), rimed cloud ice, snow (ice crystal aggregates), three categories of graupel with different densities and intercepts, frozen drops, small hail, and large hail. The concept of riming history is implemented for conversions among the graupel and frozen drops categories. The multiple precipitation ice categories allow a range of particle densities and fall velocities for simulating a variety of convective storms with minimal parameter tuning. The scheme is applied to two cases-an idealized continental multicell storm that demonstrates the ice precipitation process, and a small Florida maritime storm in which the warm rain process is important. © 2005 American Meteorological Society."
"25926762100;6701333444;8859530100;19337612500;6508293603;7006783796;6506582181;57206029166;57198616562;","The role of cloud microphysics parameterization in the simulation of mesoscale convective system clouds and precipitation in the tropical western Pacific",2013,"10.1175/JAS-D-12-0104.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84877637605&doi=10.1175%2fJAS-D-12-0104.1&partnerID=40&md5=936dbfdba798fe7ef537cafe6cf5bd01","This paper presents a detailed analysis of convection-permitting cloud simulations, aimed at increasing the understanding of the role of parameterized cloud microphysics in the simulation of mesoscale convective systems (MCSs) in the tropical western Pacific (TWP). Simulations with three commonly used bulk microphysics parameterizations with varying complexity have been compared against satellite-retrieved cloud properties. An MCS identification and tracking algorithm was applied to the observations and the simulations to evaluate the number, spatial extent, and microphysical properties of individual cloud systems. Different from many previous studies, these individual cloud systems could be tracked over larger distances because of the large TWP domain studied. The analysis demonstrates that the simulation of MCSs is very sensitive to the parameterization of microphysical processes. The most crucial element was found to be the fall velocity of frozen condensate. Differences in this fall velocity between the experiments were more related to differences in particle number concentrations than to fall speed parameterization. Microphysics schemes that exhibit slow sedimentation rates for ice aloft experience a larger buildup of condensate in the upper troposphere. This leads to more numerous and/or larger MCSs with larger anvils. Mean surface precipitation was found to be overestimated and insensitive to the microphysical schemes employed in this study. In terms of the investigated properties, the performances of complex two-moment schemes were not superior to the simpler one-moment schemes, since explicit prediction of number concentration does not necessarily improve processes such as ice nucleation, the aggregation of ice crystals into snowflakes, and their sedimentation characteristics. © 2013 American Meteorological Society."
"7103158465;7202162685;7003663305;7005035762;","A new double-moment microphysics parameterization for application in cloud and climate models. Part II: Single-column modeling of arctic clouds",2005,"10.1175/JAS3447.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-13244276117&doi=10.1175%2fJAS3447.1&partnerID=40&md5=bb133b7dd08a2af035e57e90bb851efc","The new double-moment microphysics scheme described in Part I of this paper is implemented into a single-column model to simulate clouds and radiation observed during the period 1 April-15 May 1998 of the Surface Heat Budget of the Arctic (SHEBA) and First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment-Arctic Clouds Experiment (FIRE-ACE) field projects. Mean predicted cloud boundaries and total cloud fraction compare reasonably well with observations. Cloud phase partitioning, which is crucial in determining the surface radiative fluxes, is fairly similar to ground-based retrievals. However, the fraction of time that liquid is present in the column is somewhat underpredicted, leading to small biases in the downwelling shortwave and longwave radiative fluxes at the surface. Results using the new scheme are compared to parallel simulations using other microphysics parameterizations of varying complexity. The predicted liquid water path and cloud phase is significantly improved using the new scheme relative to a single-moment parameterization predicting only the mixing ratio of the water species. Results indicate that a realistic treatment of cloud ice number concentration (prognosing rather than diagnosing) is needed to simulate arctic clouds. Sensitivity tests are also performed by varying the aerosol size, solubility, and number concentration to explore potential cloud-aerosol-radiation interactions in arctic stratus. © 2005 American Meteorological Society."
"56168891900;7004462778;7003578890;","Surface characteristics of observed cold pools",2008,"10.1175/2008MWR2528.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-64149125840&doi=10.1175%2f2008MWR2528.1&partnerID=40&md5=441b39a45c7187b699408ccb1f787c53","Cold pools are a key element in the organization of precipitating convective systems, yet knowledge of their typical surface characteristics is largely anecdotal. To help to alleviate this situation, cold pools from 39 mesoscale convective system (MCS) events are sampled using Oklahoma Mesonet surface observations. In total, 1389 time series of surface observations are used to determine typical rises in surface pressure and decreases in temperature, potential temperature, and equivalent potential temperature associated with the cold pool, and the maximum wind speeds in the cold pool. The data are separated into one of four convective system life cycle stages: first storms, MCS initiation, mature MCS, and MCS dissipation. Results indicate that the mean surface pressure rises associated with cold pools increase from 3.2 hPa for the first storms' life cycle stage to 4.5 hPa for the mature MCS stage before dropping to 3.3 hPa for the dissipation stage. In contrast, the mean temperature (potential temperature) deficits associated with cold pools decrease from 9.5 (9.8) to 5.4 K (5.6 K) from the first storms to the dissipation stage, with a decrease of approximately 1 K associated with each advance in the life cycle stage. However, the daytime and early evening observations show mean temperature deficits over 11 K. A comparison of these observed cold pool characteristics with results from idealized numerical simulations of MCSs suggests that observed cold pools likely are stronger than those found in model simulations, particularly when ice processes are neglected in the microphysics parameterization. The mean deficits in equivalent potential temperature also decrease with the MCS life cycle stage, starting at 21.6 K for first storms and dropping to 13.9 K for dissipation. Mean wind gusts are above 15 m sa1 for all life cycle stages. These results should help numerical modelers to determine whether the cold pools in high-resolution models are in reasonable agreement with the observed characteristics found herein. Thunderstorm simulations and forecasts with thin model layers near the surface are also needed to obtain better representations of cold pool surface characteristics that can be compared with observations. © 2008 American Meteorological Society."
"7201398636;7103126833;7005868133;7102369927;7102101132;","Impact of physics representations in the HWRFX on simulated hurricane structure and pressure-wind relationships",2012,"10.1175/MWR-D-11-00332.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84867977277&doi=10.1175%2fMWR-D-11-00332.1&partnerID=40&md5=e832a736e27020d3cea85e6dcab41b4e","Aseries of idealized experiments with theNOAAExperimentalHurricaneWeatherResearch and Forecasting Model (HWRFX) are performed to examine the sensitivity of idealized tropical cyclone (TC) intensification to various parameterization schemes of the boundary layer (BL), subgrid convection, cloud microphysics, and radiation. Results from all the experiments are compared in terms of the maximum surface 10-m wind (VMAX) and minimum sea level pressure (PMIN)-operational metrics of TC intensity-as well as the azimuthally averaged temporal and spatial structure of the tangential wind and its material acceleration. The conventional metrics of TC intensity (VMAX and PMIN) are found to be insufficient to reveal the sensitivity of the simulated TC to variations in model physics. Comparisons of the sensitivity runs indicate that (i) different boundary layer physics parameterization schemes for vertical subgrid turbulence mixing lead to differences not only in the intensity evolution in terms of VMAX and PMIN, but also in the structural characteristics of the simulated tropical cyclone; (ii) the surface drag coefficient is a key parameter that controls the VMAX-PMIN relationship near the surface; and (iii) different microphysics and subgrid convection parameterization schemes, because of their different realizations of diabatic heating distribution, lead to significant variations in the vortex structure. The quantitative aspects of these results indicate that the current uncertainties in the BL mixing, surface drag, and microphysics parameterization schemes have comparable impacts on the intensity and structure of simulated TCs. The results also indicate that there is a need to include structural parameters in the HWRFX evaluation. © 2012 American Meteorological Society."
"22954771200;35578543700;","On the height of the warm core in tropical cyclones",2012,"10.1175/JAS-D-11-010.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84864847963&doi=10.1175%2fJAS-D-11-010.1&partnerID=40&md5=fd41f25d6ccdaf1c3f045efe6092cf96","The warm-core structure of tropical cyclones is examined in idealized simulations using the Weather Research and Forecasting (WRF) Model. The maximum perturbation temperature in a control simulation occurs in the midtroposphere (5-6 km), in contrast to the upper-tropospheric (>10 km) warm core that is widely believed to be typical. This conventional view is reassessed and found to be largely based on three case studies, and it is argued that the ""typical"" warm-core structure is actually not well known. In the control simulation, the height of the warm core is nearly constant over a wide range of intensities. From additional simulations in which either the size of the initial vortex or the microphysics parameterization is varied, it is shown that the warm core is generally found at 4-8 km. A secondary maximumoften develops near 13-14 km but is almost always weaker than the primary warm core. It is demonstrated that microwave remote sensing instruments are of insufficient resolution to detect this midlevel warm core, and the conclusions of some studies that have utilized these instruments may not be reliable. Using simple arguments based on thermal wind balance, it is shown that the height of the warm core is not necessarily related to either the height where the vertical shear of the tangential winds is maximized or the height where the radial temperature gradient is maximized. In particular, changes in the height of the warm core need not imply changes in either the intensity of the storm or in the manner in which the winds in the eyewall decay with height. © 2012 American Meteorological Society."
"9239331500;6602351024;","Sedimentation-induced errors in bulk microphysics schemes",2010,"10.1175/2010JAS3541.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-78651095249&doi=10.1175%2f2010JAS3541.1&partnerID=40&md5=9940927306407282d44e538e348976b1","The computation of hydrometeor sedimentation in one-moment, two-moment, and three-moment bulk microphysics parameterizations is examined in the context of a 1D model, with no other microphysical processes active. The solution from an analytic bin model is used as a reference against which the bulk model simulations are compared. Errors in the computed (nonprognostic) moments from 0 to 7 from the bulk model runs are examined. In addition to the commonly used predicted variables (number concentration, mass, and reflectivity), bulk scheme configurations with alternative combinations of prognostic moments are considered. While the extra degree of freedom in a two-moment scheme adds realism to the simulation of sedimentation over a one-moment scheme, the standard practice of imposing a constant relative dispersion in the particle size distribution results in considerable errors in some of the computed moments. The error can be shifted to different moments by selecting different prognostic moments. For three-moment schemes, the error is considerably reduced over a wide range of computed moments and there is much less sensitivity to the choice of prognostic variables. Two alternative approaches are proposed for modifying the computation of sedimentation in two-moment schemes to reduce problems associated with excess size sorting. The first approach uses a diagnostic relative dispersion (shape) parameter, generalized for any pair of prognostic moments. The second involves progressively reducing the differential fall velocities between the moments and is therefore applicable for schemes that hold the shape parameter constant. Both approaches greatly reduce the errors in the computed moments, including those on which microphysical process rates depend, and are easily applied to existing two-moment schemes. © 2010 American Meteorological Society."
"6701873414;7003468747;25953950400;","Analytical solutions to the collection growth equation: comparison with approximate methods and application to cloud microphysics parameterization schemes",1990,"10.1175/1520-0469(1990)047<2871:ASTTCG>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0025593415&doi=10.1175%2f1520-0469%281990%29047%3c2871%3aASTTCG%3e2.0.CO%3b2&partnerID=40&md5=0ff777d4fab61026438e2622f714a766","A closed form solution for the collection growth equation as used in bulk microphysical parameterizations is derived. Although the general form is mathematically complex, it can serve as a benchmark for testing a variety of approximations. Two special cases that can immediately be implemented in existing cloud models are also presented. This solution is used to evaluate two commonly used approximations. The effect of the selection of different basis functions is also investigated. -Authors"
"16246205000;55738957800;","Microphysics parameterization for convective clouds in a global climate model: Description and single-column model tests",2011,"10.1029/2010JD014833","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79251603439&doi=10.1029%2f2010JD014833&partnerID=40&md5=abadfc0569434b178f66e1e2485c58ca","An efficient two-moment microphysics parameterization scheme for convective clouds is developed to improve the representation of convective clouds and its interactions with stratiform clouds and aerosol in global climate models (GCMs). The scheme explicitly treats mass mixing ratio and number concentration of four hydrometeor species (cloud water, cloud ice, rain, and snow) and describes several microphysical processes, including autoconversion, self-collection, collection between hydrometeor species, freezing, cloud ice nucleation, droplet activation, and sedimentation. Thus this physically based scheme is suitable for investigating the interaction between convection and aerosol and the indirect aerosol effect on climate. An evaluation of the scheme in the single-column version of NCAR Community Atmospheric Model version 3.5 (CAM3.5) with the Tropical Warm Pool-International Cloud Experiment (TWP-ICE) data shows that the simulation of cloud microphysical properties in convective core is significantly improved, indicating that the new parameterization describes the microphysical processes in convection reasonably well. The contribution from convective detrainment to large-scale cloud ice and liquid water budgets is enhanced greatly. With more realistic convective cloud microphysical properties and their detrainment, the surface stratiform precipitation, which is seriously underestimated in the model, is increased by a factor of roughly 2.5, and therefore is much closer to the observations. In addition, the simulations of net surface shortwave radiation flux, OLR, specific humidity, and temperature are also improved to some extent. Sensitivity experiments show that the microphysics scheme is moderately sensitive to model vertical resolution, updraft vertical velocity, and numerics, but less so to the lower boundary conditions of hydrometeor budget equations. The experiments with climatological aerosol distribution show that convective precipitation is suppressed with increasing aerosol amount, consistent with some available observations. Copyright 2011 by the American Geophysical Union."
"55441669800;6507113463;7006095466;","Simulation of a Himalayan cloudburst event",2006,"10.1007/BF02702044","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33746375337&doi=10.1007%2fBF02702044&partnerID=40&md5=74e0eb9ecf78d604908a55812d0ff2fb","Intense rainfall often leads to floods and landslides in the Himalayan region even with rainfall amounts that are considered comparatively moderate over the plains; for example, 'cloudbursts', which are devastating convective phenomena producing sudden high-intensity rainfall (∼10 cm per hour) over a small area. Early prediction and warning of such severe local weather systems is crucial to mitigate societal impact arising from the accompanying flash floods. We examine a cloudburst event in the Himalayan region at Shillagarh village in the early hours of 16 July 2003. The storm lasted for less than half an hour, followed by flash floods that affected hundreds of people. We examine the fidelity of MM5 configured with multiple-nested domains (81, 27, 9 and 3km grid-resolution) for predicting a cloudburst event with attention to horizontal resolution and the cloud microphysics parameterization. The MM5 model predicts the rainfall amount 24 hours in advance. However, the location of the cloudburst is displaced by tens of kilometers. © Printed in India."
"7005212820;7202208382;","Liquid and ice cloud microphysics in the CSU general circulation model. Part II: Impact on cloudiness, the earth's radiation budget, and the general circulation of the atmosphere",1996,"10.1175/1520-0442(1996)009<0530:LAICMI>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029768949&doi=10.1175%2f1520-0442%281996%29009%3c0530%3aLAICMI%3e2.0.CO%3b2&partnerID=40&md5=a549e7e8b0e0bb5ec23505c89a688765","A prognostic equation for the mass of condensate associated with large-scale cloudiness introduces a direct coupling between the atmospheric moisture budget and the radiation budget through interactive cloud amounts and cloud optical properties. We have compared the cloudiness, the top-of-the-atmosphere and surface radiation budgets, the radiative forcing of clouds, and the atmospheric general circulation simulated with the Colorado State University general circulation model with and without such a prognostic cloud parameterization. In the EAULIQ run, the radiative effects of cloud water, cloud ice, and snow are considered; those of rain are omitted. The cloud optical depth and cloud infrared emissivity depend on the cloud water, cloud ice, and snow paths predicted by a bulk cloud microphysics parameterization. In the CONTROL run, a conventional large-scale condensation scheme is used. Cloud optical properties depend on the mean cloud temperatures. Results are presented in terms of January and July means. Comparisons with data from the International Satellite Cloud Climatology Project and the Earth Radiation Budget Experiment show that EAULIQ yields improved simulations of the geographical distributions of the simulated cloudiness, the top-of-the-atmosphere radiation budget, and the longwave and shortwave cloud radiative forcings. Differences between EAULIQ and CONTROL are largest in the Tropics and are mostly due to a decrease, in the EAULIQ run, in the amount and optical thickness of upper-tropospheric clouds. In particular, the cold bias in the outgoing longwave radiation and the overestimation of the planetary albedo obtained in the CONTROL run over the tropical convective regions are substantially reduced. Differences in the radiative and latent heating rates between EAULIQ and CONTROL lead to some improvements in the atmospheric general circulation simulated by EAULIQ when compared against statistics on the observed circulation assembled by the European Centre for Medium-Range Weather Forecasts. When compared to CONTROL, EAULIQ yields a warmer troposphere except below 8 km between 30°N and 30°S. The mean meridional circulation is significantly weakened in the EAULIQ run."
"7403590856;6701873414;7410372222;6701701444;","Dynamical and microphysical retrievals from Doppler radar observations of a deep convective cloud",2000,"10.1175/1520-0469(2000)057<0262:DAMRFD>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0034651146&doi=10.1175%2f1520-0469%282000%29057%3c0262%3aDAMRFD%3e2.0.CO%3b2&partnerID=40&md5=81685f7e0d78bd8e9fae255a72e6dc26","A four-dimensional variational data assimilation system consisting of a three-dimensional time-dependent cloud model with both liquid and ice phase microphysics parameterization was used to assimilate radar data into a cloud model. Data of a severe thunderstorm observed during the Cooperative Huntsville Meteorological Experiment project were assimilated and results compared to a conventional analysis. The analysis system was able to retrieve all the prominent features of the storm, but differed in some of the details. However, the consistency of this retrieval dataset lent credence to the results. It was found that the algorithm was very sensitive to several coefficients in the microphysical and turbulence parameterizations. Simulations proved to be unable to reproduce the evolution of the observed storm even with parameterization coefficients set at values that produce reasonable storm evolutions. This result has implications for short-range forecasting of convective events. Such forecasts require initial fields that currently can only be derived from observations such as used in this study. The problems with assimilating radar observations point to additional work to design parameterizations that allow models to more accurately simulate actual observed storms.A four-dimensional variational data assimilation system consisting of a three-dimensional time-dependent cloud model with both liquid and ice phase microphysics parameterization was used to assimilate radar data into a cloud model. Data of a severe thunderstorm observed during the Cooperative Huntsville Meteorological Experiment project were assimilated and results compared to a conventional analysis. The analysis system was able to retrieve all the prominent features of the storm, but differed in some of the details. However, the consistency of this retrieval dataset lent credence to the results. It was found that the algorithm was very sensitive to several coefficients in the microphysical and turbulence parameterizations. Simulations proved to be unable to reproduce the evolution of the observed storm even with parameterization coefficients set at values that produce reasonable storm evolutions. This result has implications for short-range forecasting of convective events. Such forecasts require initial fields that currently can only be derived from observations such as used in this study. The problems with assimilating radar observations point to additional work to design parameterizations that allow models to more accurately simulate actual observed storms."
"26530857000;57197319901;7004593510;","Numerical simulations of Mediterranean heavy precipitation events with the WRF model: A verification exercise using different approaches",2015,"10.1016/j.atmosres.2015.05.010","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84936124965&doi=10.1016%2fj.atmosres.2015.05.010&partnerID=40&md5=8e77fd1d3d442ab1ec0bacc5ca5d7833","An intercomparison of eight different microphysics parameterization schemes available in the Weather Research and Forecasting (WRF) model and an analysis of the sensitivity of predicted precipitation to horizontal resolution are presented in this paper. Three different case studies, corresponding to severe rainfall events occurred over the Liguria region (Italy) between October 2010 and November 2011, have been considered. In all the selected cases, the formation of a quasi-stationary mesoscale convective system over the Ligurian Sea interacting with local dynamical effects (orographically-induced low-level wind and temperature gradients) played a crucial role in the generation of severe precipitations. The data set used to evaluate model performances has been extracted from the official regional network, composed of about 150 professional WMO-compliant stations. Two different strategies have been exploited to assess the model skill in forecasting precipitation: a traditional approach, where forecasts and observations are matched on a point-by-point basis, and an object-based method where model success is based on the correct localization and intensity of precipitation patterns. This last method overcomes the known fictitious models performance degradation for increasing spatial resolution. As remarkable results of this analysis, a clear role of horizontal resolution on the model performances accompanied by the identification of a set of best-performing parameterization schemes emerge. The outcomes presented here offer important suggestions for operational weather prediction systems under potentially dangerous heavy precipitations triggered by the mechanisms discussed throughout the paper. © 2015 Elsevier B.V."
"7103158465;7402584913;","Intercomparison of bulk cloud microphysics schemes in mesoscale simulations of springtime Arctic mixed-phase stratiform clouds",2006,"10.1175/MWR3154.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33746929061&doi=10.1175%2fMWR3154.1&partnerID=40&md5=d5c15a7fca7ae0b352d6b2bf1b2349ff","A persistent, weakly forced, horizontally extensive mixed-phase boundary layer cloud observed on 4-5 May 1998 during the Surface Heat Budget of the Arctic Ocean (SHEBA)/First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment-Arctic Clouds Experiment (FIRE-ACE) is modeled using three different bulk microphysics parameterizations of varying complexity implemented into the polar version of the fifth-generation Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model (MM5). The two simpler schemes predict mostly ice clouds and very little liquid water, while the complex scheme is able to reproduce the observed persistence and horizontal extent of the mixed-phase stratus deck. This mixed-phase cloud results in radiative warming of the surface, the development of a cloud-topped, surface-based mixed layer, and an enhanced precipitation rate. In contrast, the optically thin ice clouds predicted by the simpler schemes lead to radiative cooling of the surface, a strong diurnal cycle in the boundary layer structure, and very weak precipitation. The larger surface precipitation rate using the complex scheme is partly balanced by an increase in the turbulent flux of water vapor from the surface to the atmosphere. This enhanced vapor flux is attributed to changes in the surface and boundary layer characteristics induced by the cloud itself, although cloud-surface interactions appear to be exaggerated in the model compared with reality. The prediction of extensive mixed-phase stratus by the complex scheme is also associated with increased surface pressure and subsidence relative to the other simulations. Sensitivity tests show that the detailed treatment of ice nucleation and prediction of snow particle number concentration in the complex scheme suppresses ice particle concentration relative to the simpler schemes, reducing the vapor deposition rate (for given values of bulk ice mass and ice supersaturation) and leading to much greater amounts of liquid water and mixed-phase cloudiness. These results suggest that the treatments of ice nucleation and the snow intercept parameter in the simpler schemes, which are based upon midlatitude observations, are inadequate for simulating the weakly forced mixed-phase clouds endemic to the Arctic. © 2006 American Meteorological Society."
"9239331500;7006864972;","A multimoment bulk microphysics parameterization. Part IV: Sensitivity experiments",2006,"10.1175/JAS3817.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33846120616&doi=10.1175%2fJAS3817.1&partnerID=40&md5=2da46d0df29cd1c5252ef67546e535bd","This is the fourth in a series of papers exploring the effects of the number of predicted moments in bulk microphysics schemes. In Part III, the three-moment version of a new multimoment scheme was used to simulate a severe hailstorm. The model successfully reproduced many of the observed gross characteristics, including the reflectivity structure and the maximum hail sizes at the ground. In this paper, the authors compare a series of sensitivitv experiments using various one- and two-moment versions of the scheme with the three-moment version to explore the effects of predicting additional moments on the simulated hydrometeor fields, precipitation, and storm dynamics. Six sensitivity runs were performed. They varied in their ability to reproduce the precipitation pattern, storm structure, and peak values of microphysical fields of the control simulation. The two-moment simulations, which used diagnostic relations to prescribe the relative dispersion parameter, α, closely reproduced the spatial pattern, quantity, and phase of the precipitation at the surface as well as the overall storm structure, propagation speed, and peak values of several hydrometeor fields. The two-moment simulations, which used fixed values of α, on the other hand, differed more from the control. The runs using one-moment versions of the scheme were considerably different from each other and were poor at reproducing the control simulation. The results suggest that there is a dramatic improvement in the simulation moving from one- to two-moment schemes. For the case studied, it was found that if maximum particle size is not of concern, a two-moment scheme with a diagnostic dispersion parameter can reproduce most of the important aspects in a hailstorm simulation with a three-moment scheme. © 2006 American Meteorological Society."
"8723504500;57215311656;57207238566;55582769600;7103158465;","Modeling convective-stratiform precipitation processes on a Mei-Yu front with the Weather Research and Forecasting model: Comparison with observations and sensitivity to cloud microphysics parameterizations",2010,"10.1029/2010JD013873","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77957556463&doi=10.1029%2f2010JD013873&partnerID=40&md5=fc0315bcfff63def4a725b224d647c20","Deep convective-scale simulations of the linear mesoscale convective systems (MCSs) formed on a Mei-Yu front over the Huai River basin in China on 7-8 July 2007 were conducted using the Advanced Research Weather Research and Forecasting model to investigate impacts of cloud microphysics parameterizations on simulated convective-stratiform precipitation processes. Eight simulations were performed with identical configurations, except for differences in the cloud microphysics parameterizations. Measurements from rain gauges, ground-based weather radars, and the Tropical Rainfall Measuring Mission satellite Precipitation Radar were used to quantitatively evaluate the model results. While all of the simulations largely capture the observed large-scale characteristics of the precipitation event, notable differences among the simulations are found in the morphology and evolution of the MCSs at mesoscale and cloud scale. Significant influences on the coupling between dynamical and microphysical processes at the resolved deep convective scale by the various microphysical parameterizations are evident. On the one hand, the different microphysical schemes produce not only substantial differences in intensity of convective precipitation but also distinguishable vertical distributions of latent heating and condensate loading in the deep convective regions, which in turn results in significant differences in the vertical distributions of vertical air velocity and in the heights and strength of detrainment from deep convective regions. Consequently, detrainment of hydrometeors and positively buoyant air from the deep convective regions to the stratiform regions is significantly different, which impacts the formation and growth of ice-phase hydrometeors at the upper levels and thus surface rainfall rates in the stratiform regions. On the other hand, prediction of rain size distribution significantly impacts the simulated rain evaporation rates and mass-weighted rain fall speeds, and hence rain flux. Improper determination of the intercept parameter of rain size distribution can result in unrealistic features in the morphology of the storm and can have substantial impacts on precipitation distribution and evolution. Copyright 2010 by the American Geophysical Union."
"7003666669;7006270084;","Computationally efficient approximations to stratiform cloud microphysics parameterization",1992,"10.1175/1520-0493(1992)120<1572:CEATSC>2.0.CO;2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0027039505&doi=10.1175%2f1520-0493%281992%29120%3c1572%3aCEATSC%3e2.0.CO%3b2&partnerID=40&md5=0b1b1b0a892f360b9d4dd25431477cc7","By diagnosing rather than predicting rain and snow concentrations and by assuming instantaneous melting of snow, we have found that the permissible time step is increased tenfold (to 2-6 min) with little loss in accuracy for vertical motions and time scales characteristic of those resolved by general circulation models (GCMs). Such time steps are sufficiently long to permit application of bulk cloud microphysical parameterizations to GCMs for multiyear global simulations. However, we also find that the vertical resolution must be considerably finer (100-200m) than that currently employed in GCMs. -from Authors"
"56000281400;9239331500;","Microphysical observations and mesoscale model simulation of warm fog case during FRAM project",2007,"10.1007/s00024-007-0212-9","https://www.scopus.com/inward/record.uri?eid=2-s2.0-34547601695&doi=10.1007%2fs00024-007-0212-9&partnerID=40&md5=28feaccf6286cb94f3eaa36f663d7f82","The objective of this work is to apply a new microphysical parameterization for fog visibility for potential use in numerical weather forecast simulations, and to compare the results with ground-based observations. The observations from the Fog Remote Sensing And Modeling (FRAM) field which took place during the winter of 2005 - 2006 over southern Ontario, Canada (Phase I) were used in the analysis. The liquid water content (LWC), droplet number concentration (Nd), and temperature (T) were obtained from the fog measuring device (FMD) spectra and Rosemount probe, correspondingly. The visibility (Vis) from a visibility meter, liquid water path from microwave radiometers (MWR), and inferred fog properties such as mean volume diameter, LWC, and Nd were also used in the analysis. The results showed that Vis is nonlinearly related to both LWC and Nd. Comparisons between newly derived parameterizations and the ones already in use as a function of LWC suggested that if models can predict the total Nd and LWC at each time step using a detailed microphysics parameterization, Vis can then be calculated for warm fog conditions. Using outputs from the Canadian Mesoscale Compressible Community (MC2) model, being tested with a new multi-moment bulk microphysical scheme, the new Vis parameterization resulted in more accurate Vis values where the correction reached up to 20-50%. © Birkhäuser Verlag, Basel, 2007."
"7409792174;7006095466;","Sensitivity of cloud-resolving simulations of warm-season convection to cloud microphysics parameterizations",2007,"10.1175/MWR3437.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-34548257816&doi=10.1175%2fMWR3437.1&partnerID=40&md5=62bcf988b8ce10c2e03df1958227e6e8","This paper investigates the effects of cloud microphysics parameterizations on simulations of warm-season precipitation at convection-permitting grid spacing. The objective is to assess the sensitivity of summertime convection predictions to the bulk microphysics parameterizations (BMPs) at fine-grid spacings applicable to the next generation of operational numerical weather prediction models. Four microphysical parameterization schemes are compared: simple ice (Dudhia), four-class mixed phase (Reisner et al.), Goddard five-class mixed phase (Tao and Simpson), and five-class mixed phase with graupel (Reisner et al.). The experimentation involves a 7-day episode (3-9 July 2003) of U.S. midsummer convection under moderate large-scale forcing. Overall, the precipitation coherency manifested as eastward-moving organized convection in the lee of the Rockies is insensitive to the choice of the microphysics schemes, and the latent heating profiles are also largely comparable among the BMPs. The upper-level condensate and cloudiness, upper-level radiative cooling/ heating, and rainfall spectrum are the most sensitive, whereas the domain-mean rainfall rate and areal coverage display moderate sensitivity. Overall, the three mixed-phase schemes outperform the simple ice scheme, but a general conclusion about the degree of sophistication in the microphysics treatment and the performance is not achievable. © 2007 American Meteorological Society."
"35316923500;7102712173;7401539646;7102080550;57205302128;","Application of object-based time-domain diagnostics for tracking precipitation systems in convection-allowing models",2014,"10.1175/WAF-D-13-00098.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84902212483&doi=10.1175%2fWAF-D-13-00098.1&partnerID=40&md5=855a9a5a53b7b3344bc162c03e0f9265","Meaningful verification and evaluation of convection-allowing models requires approaches that do not rely on point-to-point matches of forecast and observed fields. In this study, one such approach-a beta version of the Method for Object-Based Diagnostic Evaluation (MODE) that incorporates the time dimension [known asMODEtime-domain (MODE-TD)]-was applied to 30-h precipitation forecasts from four 4-km grid-spacing members of the 2010 Storm-Scale Ensemble Forecast system with different microphysics parameterizations. Including time in MODE-TD provides information on rainfall system evolution like lifetime, timing of initiation and dissipation, and translation. The simulations depicted the spatial distribution of time-domain precipitation objects across the United States quite well. However, all simulations overpredicted the number of objects, with the Thompson microphysics scheme overpredicting the most and theMorrison method the least. For the smallest smoothing radius and rainfall threshold used to define objects [8 km and 0.10 in. (1 in. 5 2.54 cm), respectively], the most common object duration was 3 h in both models and observations. With an increased smoothing radius and rainfall threshold, the most common duration became shorter. The simulations depicted the diurnal cycle of object frequencies well, but overpredicted object frequencies uniformly across all forecast hours. The simulations had spurious maxima in initiating objects at the beginning of the forecast and a corresponding spurious maximum in dissipating objects slightly later. Examining average object velocities, a slow bias was found in the simulations, which was most pronounced in the Thompson member. These findings should aid users and developers of convection-allowing models and motivate future work utilizing time-domain methods for verifying high-resolution forecasts. © 2014 American Meteorological Society."
"34881780600;7202048112;7006432091;6506328135;20433705700;57188966058;57195922668;8511991900;","Structure and Evolution of Mesoscale Convective Systems: Sensitivity to Cloud Microphysics in Convection-Permitting Simulations Over the United States",2018,"10.1029/2018MS001305","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050487942&doi=10.1029%2f2018MS001305&partnerID=40&md5=9fe0eeb572cf5f1851c98c0fa65ff57b","Regional climate simulations over the continental United States were conducted for the 2011 warm season using the Weather Research and Forecasting model at convection-permitting resolution (4 km) with two commonly used microphysics parameterizations (Thompson and Morrison). Sensitivities of the simulated mesoscale convective system (MCS) properties and feedbacks to large-scale environments are systematically examined against high-resolution geostationary satellite and 3-D mosaic radar observations. MCS precipitation including precipitation amount, diurnal cycle, and distribution of hourly precipitation intensity are reasonably captured by the two simulations despite significant differences in their simulated MCS properties. In general, the Thompson simulation produces better agreement with observations for MCS upper level cloud shield and precipitation area, convective feature horizontal and vertical extents, and partitioning between convective and stratiform precipitation. More importantly, Thompson simulates more stratiform rainfall, which agrees better with observations and results in top-heavier heating profiles from robust MCSs compared to Morrison. A stronger dynamical feedback to the large-scale environment is therefore seen in Thompson, wherein an enhanced mesoscale vortex behind the MCS strengthens the synoptic-scale trough and promotes advection of cool and dry air into the rear of the MCS region. The latter prolongs the MCS lifetimes in the Thompson relative to the Morrison simulations. Hence, different treatment of cloud microphysics not only alters MCS convective-scale dynamics but also has significant impacts on their macrophysical properties such as lifetime and precipitation. As long-lived MCSs produced 2–3 times the amount of rainfall compared to short-lived ones, cloud microphysics parameterizations have profound impact in simulating extreme precipitation and the hydrologic cycle. ©2018. The Authors."
"55717074000;7401936984;7401974644;7402064802;55542833500;7410041005;8859530100;7003666669;8373634800;25629339800;6506424404;","Testing cloud microphysics parameterizations in NCAR CAM5 with ISDAC and M-PACE observations",2011,"10.1029/2011JD015889","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84855322273&doi=10.1029%2f2011JD015889&partnerID=40&md5=7916886317a304d4249a0d8efed39652","Arctic clouds simulated by the National Center for Atmospheric Research (NCAR) Community Atmospheric Model version 5 (CAM5) are evaluated with observations from the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Indirect and Semi-Direct Aerosol Campaign (ISDAC) and Mixed-Phase Arctic Cloud Experiment (M-PACE), which were conducted at its North Slope of Alaska site in April 2008 and October 2004, respectively. Model forecasts for the Arctic spring and fall seasons performed under the Cloud-Associated Parameterizations Testbed framework generally reproduce the spatial distributions of cloud fraction for single-layer boundary-layer mixed-phase stratocumulus and multilayer or deep frontal clouds. However, for low-level stratocumulus, the model significantly underestimates the observed cloud liquid water content in both seasons. As a result, CAM5 significantly underestimates the surface downward longwave radiative fluxes by 20-40 W m -2. Introducing a new ice nucleation parameterization slightly improves the model performance for low-level mixed-phase clouds by increasing cloud liquid water content through the reduction of the conversion rate from cloud liquid to ice by the Wegener-Bergeron-Findeisen process. The CAM5 single-column model testing shows that changing the instantaneous freezing temperature of rain to form snow from-5°C to-40°C causes a large increase in modeled cloud liquid water content through the slowing down of cloud liquid and rain-related processes (e.g., autoconversion of cloud liquid to rain). The underestimation of aerosol concentrations in CAM5 in the Arctic also plays an important role in the low bias of cloud liquid water in the single-layer mixed-phase clouds. In addition, numerical issues related to the coupling of model physics and time stepping in CAM5 are responsible for the model biases and will be explored in future studies. Copyright 2011 by the American Geophysical Union."
"56147558700;35586100500;6507082261;","Influence of cloud-radiative forcing on tropical cyclone structure",2014,"10.1175/JAS-D-13-0265.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84899768573&doi=10.1175%2fJAS-D-13-0265.1&partnerID=40&md5=865238857035fd71e8248308f31dc74c","The authors demonstrate how and why cloud-radiative forcing (CRF), the interaction of hydrometeors with longwave and shortwave radiation, can influence tropical cyclone structure through ""semi idealized""integrations of the Hurricane Weather Research and Forecasting model (HWRF) and an axisymmetric cloud model. Averaged through a diurnal cycle, CRF consists of pronounced cooling along the anvil top and weak warming through the cloudy air, which locally reverses the large net cooling that occurs in the troposphere under clear-sky conditions. CRF itself depends on the microphysics parameterization and represents one of the major reasons why simulations can be sensitive to microphysical assumptions. By itself, CRF enhances convective activity in the tropical cyclone's outer core, leading to a wider eye, a broader tangential wind field, and a stronger secondary circulation. This forcing also functions as a positive feedback, assisting in the development of a thicker and more radially extensive anvil than would otherwise have formed. These simulations clearly show that the weak (primarily longwave) warming within the cloud anvil is the major component of CRF, directly forcing stronger upper-tropospheric radial outflow as well as slow, yet sustained, ascent throughout the outer core. In particular, this ascent leads to enhanced convective heating, which in turn broadens the wind field, as demonstrated with dry simulations using realistic heat sources. As a consequence, improved tropical cyclone forecasting in operational models may depend on proper representation of cloud-radiative processes, as they can strongly modulate the size and strength of the outer wind field that can potentially influence cyclone track as well as the magnitude of the storm surge. © 2014 American Meteorological Society."
"8067118800;7202899330;13402835300;56162305900;6701752471;10241462700;8918407000;","Evaluation of the warm rain formation process in global models with satellite observations",2015,"10.1175/JAS-D-14-0265.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84944955162&doi=10.1175%2fJAS-D-14-0265.1&partnerID=40&md5=31519f73467ef714734722762e6f9a5d","This study examines the warm rain formation process over the global ocean in global climate models. Methodologies developed to analyze CloudSat and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations are employed to investigate the cloud-to-precipitation process of warm clouds and are applied to the model results to examine how the models represent the process for warm stratiform clouds. Despite a limitation of the present study that compares the statistics for stratiform clouds in climate models with those from satellite observations, including both stratiform and (shallow) convective clouds, the statistics constructed with the methodologies are compared between the models and satellite observations to expose their similarities and differences. A problem common to some models is that they tend to produce rain at a faster rate than is observed. These model characteristics are further examined in the context of cloud microphysics parameterizations using a simplified one-dimensional model of warm rain formation that isolates key microphysical processes from full interactions with other processes in global climate models. The one-dimensional model equivalent statistics reproduce key characteristics of the global model statistics when corresponding autoconversion schemes are assumed in the one-dimensional model. The global model characteristics depicted by the statistics are then interpreted as reflecting behaviors of the autoconversion parameterizations adopted in the models. Comparisons of the one-dimensional model with satellite observations hint at improvements to the formulation of the parameterization scheme, thus offering a novel way of constraining key parameters in autoconversion schemes of global models. © 2015 American Meteorological Society."
"57200702127;8511991900;7404865816;7202048112;8877858700;","Improving bulk microphysics parameterizations in simulations of aerosol effects",2013,"10.1002/jgrd.50432","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880304412&doi=10.1002%2fjgrd.50432&partnerID=40&md5=8fc1e9d3b39a15227ef1edc10e845e2d","To improve the microphysical parameterizations for simulations of the aerosol effects in regional and global climate models, the Morrison double-moment bulk microphysical scheme presently implemented in the Weather Research and Forecasting model is modified by replacing the prescribed aerosols in the original bulk scheme (Bulk-OR) with a prognostic double-moment aerosol representation to predict both aerosol number concentration and mass mixing ratio (Bulk-2M). Sensitivity modeling experiments are performed for two distinct cloud regimes: maritime warm stratocumulus clouds (Sc) over southeast Pacific Ocean from the VOCALS project and continental deep convective clouds in the southeast of China. The results from Bulk-OR and Bulk-2M are compared against atmospheric observations and simulations produced by a spectral bin microphysical scheme (SBM). The prescribed aerosol approach (Bulk-OR) produces unreliable aerosol and cloud properties throughout the simulation period, when compared to the results from those using Bulk-2M and SBM, although all of the model simulations are initiated by the same initial aerosol concentration on the basis of the field observations. The impacts of the parameterizations of diffusional growth and autoconversion of cloud droplets and the selection of the embryonic raindrop radius on the performance of the bulk microphysical scheme are also evaluated by comparing the results from the modified Bulk-2M with those from SBM simulations. Sensitivity experiments using four different types of autoconversion schemes reveal that the autoconversion parameterization is crucial in determining the raindrop number, mass concentration, and drizzle formation for warm stratocumulus clouds. An embryonic raindrop size of 40 μm is determined as a more realistic setting in the autoconversion parameterization. The saturation adjustment employed in calculating condensation/evaporation in the bulk scheme is identified as the main factor responsible for the large discrepancies in predicting cloud water in the Sc case, suggesting that an explicit calculation of diffusion growth with predicted supersaturation is necessary to improve the bulk microphysics scheme. Lastly, a larger rain evaporation rate below clouds is found in the bulk scheme in comparison to the SBM simulation, which may contribute to a lower surface precipitation in the bulk scheme. © 2013. American Geophysical Union. All Rights Reserved."
"9239331500;7006864972;","A multimoment bulk microphysics parameterization. Part III: Control simulation of a hailstorm",2006,"10.1175/JAS3816.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33846143501&doi=10.1175%2fJAS3816.1&partnerID=40&md5=bd395d9a13e1ad291c580cc71f2509c6","With continuous increase in the resolution of operational numerical weather prediction models, grid-scale saturation schemes that model cloud microphysics are becoming increasingly important. In Parts I and II of this study, the importance of the relative dispersion of the hydrometeor size distribution in bulk microphysics parameterizations was demonstrated and a closure approach for a three-moment scheme was proposed. In this paper, the full three-moment version of the new multimoment scheme is tested in a 3D simulation of a severe hailstorm. The modeled microphysical fields are examined, with particular attention paid to the simulated hail fields including the maximum hail sizes at the ground. A mesoscale model was initialized using synoptic analyses and successively nested to a resolution of 1 km. When compared to observations of the real storm from a nearby radar, the simulated storm reproduced several of the observed characteristics including the direction and speed of propagation, a bounded weak echo region, hook echo, mesocyclone, and a suspended overhang region. The magnitudes of radar reflectivity and surface precipitation are also well simulated. The mass contents, total number concentrations, equivalent reflectivities, and mean mass diameters of each hydrometeor category in the model were examined. The spatial distributions of the various hydrometeors throughout the storm appeared realistic and their values were consistent with published observations from other storms. Using the three predicted parameters of the gamma size distribution for hail, a method was introduced to determine the maximum hail size simulated from a bulk scheme that is physically observable. The observed storm produced golf ball-sized hail while the simulation produced walnut-sized hail at approximately the same time and location. The results suggest that because of the additional information provided about the size distribution, there is added value in prognosing the relative dispersion parameter of a given hydrometeor category in a bulk scheme. © 2006 American Meteorological Society."
"8511991900;57195922668;42062523800;7103158465;56611485900;6603431534;55723061900;7401796996;8658386900;7005742394;55258548500;6603381720;9239331500;56439778100;7403077486;57200702127;","Cloud-resolving model intercomparison of an MC3E squall line case: Part I—Convective updrafts",2017,"10.1002/2017JD026622","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85030116117&doi=10.1002%2f2017JD026622&partnerID=40&md5=628d4b6cb5191f4bf315b8cccf2aecf0","An intercomparison study of a midlatitude mesoscale squall line is performed using the Weather Research and Forecasting (WRF) model at 1 km horizontal grid spacing with eight different cloud microphysics schemes to investigate processes that contribute to the large variability in simulated cloud and precipitation properties. All simulations tend to produce a wider area of high radar reflectivity (Ze &gt; 45 dBZ) than observed but a much narrower stratiform area. The magnitude of the virtual potential temperature drop associated with the gust front passage is similar in simulations and observations, while the pressure rise and peak wind speed are smaller than observed, possibly suggesting that simulated cold pools are shallower than observed. Most of the microphysics schemes overestimate vertical velocity and Ze in convective updrafts as compared with observational retrievals. Simulated precipitation rates and updraft velocities have significant variability across the eight schemes, even in this strongly dynamically driven system. Differences in simulated updraft velocity correlate well with differences in simulated buoyancy and low-level vertical perturbation pressure gradient, which appears related to cold pool intensity that is controlled by the evaporation rate. Simulations with stronger updrafts have a more optimal convective state, with stronger cold pools, ambient low-level vertical wind shear, and rear-inflow jets. Updraft velocity variability between schemes is mainly controlled by differences in simulated ice-related processes, which impact the overall latent heating rate, whereas surface rainfall variability increases in no-ice simulations mainly because of scheme differences in collision-coalescence parameterizations. Published 2017."
"7405273411;7102080550;7202487479;7402379980;","Diagnosing the intercept parameter for exponential raindrop size distribution based on video disdrometer observations: Model development",2008,"10.1175/2008JAMC1876.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-65349100612&doi=10.1175%2f2008JAMC1876.1&partnerID=40&md5=db0ecba2dd0b52905d937516a77254fa","The exponential distribution N(D) = N0 exp(-ΛD) with a fixed intercept parameter N0 is most commonly used to represent raindrop size distribution (DSD) in rainfall estimation and in single-moment bulk microphysics parameterization schemes. Disdrometer observations show that the intercept parameter is far from constant and systematically depends on the rain type and intensity. In this study, a diagnostic relation of N0 as a function of rainwater content W is derived based on two-dimensional video disdrometer (2DVD) measurements. The data reveal a clear correlation between N0 and W in which N0 increases as W increases. To minimize the effects of sampling error, a relation between two middle moments is used to derive the N0-W relation. This diagnostic relation has the potential to improve rainfall estimation and bulk microphysics parameterizations. A parameterization scheme for warm rain processes based on the diagnostic N0 DSD model is formulated and presented. The diagnostic N0-based parameterization scheme yields less evaporation and accretion for stratiform rain than that using fixed N0. © 2008 American Meteorological Society."
"8979277400;","The interaction of cumulus convection with soil moisture distribution: an idealized simulation",1998,"10.1029/98JD00426","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032571693&doi=10.1029%2f98JD00426&partnerID=40&md5=7203a16f9fedbfd8efb3d1eeffcb9770","In order to investigate the interaction between cumulus convection and soil moisture distribution, two-dimensional numerical experiments using a regionsl atmospheric model are performed. The model roughly resolves each convective cell and represents cloud processes by a microphysics parameterization. Two long-term (60-day) integrations with relatively dry and wet conditions are made with the atmosphere-land system in a quasi-equilibrium state. Though the initial and boundary conditions are horizontally homogeneous, horizontal contrasts in soil moisture spontaneously develop due to the spotty nature of convective events are initiated by the upward motion of this local circulation over the dry region. They mostly occur in th afternoon (1300-1700 LT), while convection that forms over regions that are wet throughout may occur at any time during the day. the intense precipiation over the dry region 'overdamps' the soil moisture contrast, which reults in the maintenance of a heterogeneous distribution of soil moisture."
"55793507700;57212816521;57076830500;","Validation of simulated hurricane drop size distributions using polarimetric radar",2016,"10.1002/2015GL067278","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84958060899&doi=10.1002%2f2015GL067278&partnerID=40&md5=c00f4a694b396c61a4db34c1096e3c28","Recent upgrades to the U.S. radar network now allow for polarimetric measurements of landfalling hurricanes, providing a new data set to validate cloud microphysical parameterizations used in tropical cyclone simulations. Polarimetric radar reflectivity and differential reflectivity simulated by the Weather Research and Forecasting model were compared with real radar observations from 2014 in Hurricanes Arthur and Ana. Six different microphysics parameterizations were tested that were able to capture the major features of both hurricanes, including accurate tracks, precipitation asymmetry, and the approximate intensity of the storms. A high correlation between simulated intensity and rainfall across schemes suggests an intimate link between the latent heating produced by the microphysics and the storm dynamics. Most of the parameterizations produced a higher frequency of larger raindrops than observed. The Thompson aerosol-aware bulk and explicit spectral bin microphysical schemes showed the best fidelity to the observations at a higher computational cost. © 2016. American Geophysical Union. All Rights Reserved."
"16246205000;55738957800;9249239700;","Evaluation of microphysics parameterization for convective clouds in the NCAR community atmosphere model CAM5",2012,"10.1175/JCLI-D-11-00563.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84865463788&doi=10.1175%2fJCLI-D-11-00563.1&partnerID=40&md5=be76f34957ef3f957ce31b36d0f5dc41","A physically based two-moment microphysics parameterization scheme for convective clouds is implemented in the NCAR Community Atmosphere Model version 5 (CAM5) to improve the representation of convective clouds and their interaction with large-scale clouds and aerosols. The explicit treatment of mass mixing ratio and number concentration of cloud and precipitation particles enables the scheme to account for the impact of aerosols on convection. The scheme is linked to aerosols through cloud droplet activation and ice nucleation processes and to stratiform cloud parameterization through convective detrainment of cloud liquid/ice water content (LWC/IWC) and droplet/crystal number concentration (DNC/CNC). A 5-yr simulation with the new convective microphysics scheme shows that both cloud LWC/IWC and DNC/CNC are in good agreement with observations, indicating the scheme describes microphysical processes in convection well. Moreover, the microphysics scheme is able to represent the aerosol effects on convective clouds such as the suppression of warm rain formation and enhancement of freezing when aerosol loading is increased. With more realistic simulations of convective cloud microphysical properties and their detrainment, the mid- and low-level cloud fraction is increased significantly over the ITCZ-southern Pacific convergence zone (SPCZ) and subtropical oceans, making it much closer to the observations. Correspondingly, the serious negative bias in cloud liquid water path over subtropical oceans observed in the standard CAM5 is reduced markedly. The large-scale precipitation is increased and precipitation distribution is improved as well. The long-standing precipitation bias in the western Pacific is significantly alleviated because of microphysics- thermodynamics feedbacks. © 2012 American Meteorological Society."
"7003666669;7202048112;55605773361;","Application of cloud microphysics to NCAR community climate model",1997,"10.1029/97jd00703","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0031399538&doi=10.1029%2f97jd00703&partnerID=40&md5=91f2b1e8d98e44cbef587f84e0692589","The Colorado State University Regional Atmospheric Modeling System bulk cloud inicrophysics parameterization has been applied to the treatment of stratiform clouds in the National Center for Atmospheric Research community climate model. Predicted cloud properties are mass concentrations of cloud water, cloud ice, rain, and snow and number concentration of ice. Microphysical processes treated include condensation of water vapor and evaporation of cloud water and rain, nucleation of ice crystals, vapor deposition and sublimation of cloud ice and snow, autoconversion and accretion of cloud water, aggregation and collection of cloud ice, melting of ice and snow, riming on ice and snow, and gravitational settling of ice, rain, and snow. Although the parameterization is more detailed and hence more computationally demanding than other cloud microphysics parameterizations in climate models, it treats the Bergeron-Findeisen process explicitly and hence does not require an ad hoc parameterization to distinguish liquid water and ice. A variety of simulations were performed, testing sensitivity to horizontal and vertical resolution, the treatment of ice number, droplet number, and parameterization of cumulus convection. The simulated planetary radiation balance is found to be particularly sensitive to the treatment of ice number and cumulus convection."
"8877858700;","A warm rain microphysics parameterization that includes the effect of turbulence",2008,"10.1175/2007JAS2556.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-45849096503&doi=10.1175%2f2007JAS2556.1&partnerID=40&md5=9c9b3e533c9a272abaf6534fee5b469c","A warm rain parameterization has been developed by solving the stochastic collection equation with the use of turbulent collision kernels. The resulting parameterizations for the processes of autoconversion, accretion, and self-collection are functions of the turbulent intensity of the flow and are applicable to turbulent cloud conditions ranging in dissipation rates of turbulent kinetic energy from 100 to 1500 cm2 s-3. Turbulence has a significant effect on the acceleration of the drop size distribution and can reduce the time to the formation of raindrops. When the stochastic collection equation is solved with the gravitational collision kernel for an initial distribution with a liquid water content of 1 g m-3 and 240 drops cm-3 with a mean volume radius of 10 μm, the amount of mass that is transferred to drop sizes greater than 40 μm in radius after 20 min is 0.9% of the total mass. When the stochastic collec6on equation is solved with a turbulent collision kernel for collector drops in the range of 10-30 μm with a dissipation rate of turbulent kinetic energy equal to 100 cm2 s-3, this percentage increases to 21.4. Increasing the dissipation rate of turbulent kinetic energy to 500, 1000, and 1500 cm2 s-3 further increases the percentage of mass transferred to radii greater than 40 μm after 20 min to 41%, 52%, and 58%, respectively, showing a substantial acceleration of the drop size distribution when a turbulent collision kernel that includes both turbulent and gravitational forcing replaces the purely gravitational kernel. The warm rain microphysics parameterization has been developed from direct numerical simulation (DNS) results that are characterized by Reynolds numbers that are orders of magnitude smaller than those of atmospheric turbulence. The uncertainty involved with the extrapolation of the results to high Reynolds numbers, the use of gravitational collision efficiencies, and the range of the droplets for which the effect of turbulence has been included should all be considered when interpreting results based on these new microphysics parameterizations. © 2008 American Meteorological Society."
"7005920812;6701752471;55017656900;25953950400;","Supplying local microphysics parameterizations with information about subgrid variability: Latin hypercube sampling",2005,"10.1175/JAS3624.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-26444563231&doi=10.1175%2fJAS3624.1&partnerID=40&md5=d2a932e43745984b347b2de20c3cb247","One problem in computing cloud microphysical processes in coarse-resolution numerical models is that many microphysical processes are nonlinear and small in scale. Consequently, there are inaccuracies if microphysics parameterizations are forced with grid box averages of model fields, such as liquid water content. Rather, the model needs to determine information about subgrid variability and input it into the microphysics parameterization. One possible solution is to assume the shape of the family of probability density functions (PDFs) associated with a grid box and sample it using the Monte Carlo method. In this method, the microphysics subroutine is called repeatedly, once with each sample point. In this way, the Monte Carlo method acts as an interface between the host model's dynamics and the microphysical parameterization. This avoids the need to rewrite the microphysics subroutines. A difficulty with the Monte Carlo method is that it introduces into the simulation statistical noise or variance, associated with the finite sample size. If the family of PDFs is tractable, one can sample solely from cloud, thereby improving estimates of in-cloud processes. If one wishes to mitigate the noise further, one needs a method for reduction of variance. One such method is Latin hypercube sampling, which reduces noise by spreading out the sample points in a quasi-random fashion. This paper formulates a sampling interface based on the Latin hypercube method. The associated family of PDFs is assumed to be a joint normal/ lognormal (i.e., Gaussian/lognormal) mixture. This method of variance reduction has a couple of advantages. First, the method is general: the same interface can be used with a wide variety of microphysical parameterizations for various processes. Second, the method is flexible: one can arbitrarily specify the number of hydrometeor categories and the number of calls to the microphysics parameterization per grid box per time step. This paper performs a preliminary test of Latin hypercube sa mpling. As a prototypical microphysical formula, this paper uses the Kessler autoconversion formula. The PDFs that are sampled are extracted diagnostically from large-eddy simulations (LES). Both stratocumulus and cumulus boundary layer cases are tested. In this diagnostic test, the Latin hypercube can produce somewhat less noisy time-averaged estimates of Kessler autoconversion than a traditional Monte Carlo estimate, with no additional calls to the microphysics parameterization. However, the instantaneous estimates are no less noisy. This paper leaves unanswered the question of whether the Latin hypercube method will work well in a prognostic, interactive cloud model, but this question will be addressed in a future manuscript. © 2005 American Meteorological Society."
"7103158465;7003663305;7202162685;","Modeling clouds observed at SHEBA using a bulk microphysics parameterization implemented into a single-column model",2003,"10.1029/2002jd002229","https://www.scopus.com/inward/record.uri?eid=2-s2.0-1642497645&doi=10.1029%2f2002jd002229&partnerID=40&md5=740c51c1da8f60a3f06da4d8431d8390","A single-column model coupled to a bulk microphysics parameterization (with prognostic cloud liquid water, cloud ice, rain, and snow mixing ratios) is evaluated using cloud properties retrieved at the Surface Heat Budget of the Arctic Ocean experiment (SHEBA) during the period of 1 April to 16 May 1998. Overall, the model accurately simulates the cloud boundaries and total cloud fraction, but has difficulty correctly partitioning the cloud phases and predicting the condensed water contents and paths. In particular, the mean liquid water path (LWP) is underestimated by 76%. This bias is attributed to underpredicting the liquid cloud fraction, that is, underpredicting the frequency of liquid- or mixed-phase clouds. The mean ice water path (IWP) is underestimated by 42%. Glaciation in the model occurs primarily through the preferential depositional growth of pristine ice initiated by deposition-condensation nucleation at the expense of liquid water, in contrast to glaciation mechanisms inferred from observations. Sensitivity tests are conducted to elucidate the relative importance of various microphysical parameters on the modeled cloud properties and processes. The liquid cloud fraction and mean LWP are most sensitive to uncertainties in the ice crystal number concentration, while the mean IWP is sensitive to several cloud ice/snow microphysical parameters, including the collection efficiency for riming and terminal fall velocities. The model evaluation is also discussed in the context of the spatial resolution and the approach to cloud scale separation. The unique spatial scales (particularly in the vertical) associated with Arctic stratiform clouds must be taken into account in order to correctly simulate the observed cloud properties."
"57188537991;24587207000;7402379980;7102080550;","Comparison of simulated polarimetric signatures in idealized supercell storms using two-moment bulk microphysics schemes in WRF",2016,"10.1175/MWR-D-15-0233.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84961391590&doi=10.1175%2fMWR-D-15-0233.1&partnerID=40&md5=0e34d6bffb067c2367bdba89dfc6c88a","Microphysics parameterization becomes increasingly important as the model grid spacing increases toward convection-resolving scales. The performance of several partially or fully two-moment (2M) schemes within the Weather Research and Forecasting (WRF) Model, version 3.5.1, chosen because of their well-documented advantages over one-moment (1M) schemes, is evaluated with respect to their ability in producing the well-known polarimetric radar signatures found within supercell storms. Such signatures include the ZDR and KDP columns, the ZDR arc, the midlevel ZDR and ρHV rings, the hail signature in the forward-flank downdraft, and the KDP foot. Polarimetric variables are computed from WRF Model output using a polarimetric radar simulator. It is found that microphysics schemes with a 1M rimed-ice category are unable to simulate the ZDR arc, despite containing a 2M rain category. It is also found that a hail-like rimed-ice category (in addition to graupel) may be necessary to reproduce the observed hail signature. For the microphysics schemes that only contain a graupel-like rimed-ice category, only very wet graupel particles are able to reach the lowest model level, which did not adequately reduce ZDR in this signature. The most realistic signatures overall are found with microphysics schemes that are fully 2M with a separate hail category. © 2016 American Meteorological Society."
"7102743829;","A cumulus cloud microphysics parameterization for cloud-resolving models",2013,"10.1175/JAS-D-12-0183.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84877319789&doi=10.1175%2fJAS-D-12-0183.1&partnerID=40&md5=1ee8262805f7c99c8b7d2361c03016b6","A microphysical parameterization for shallow cumulus and boundary layer stratocumulus clouds has been developed. Similar to the Khairoutdinov and Kogan parameterization for stratocumulus clouds, the new parameterization is based on an explicit microphysical large-eddy simulation (LES) model as a data source and benchmark for comparison. The predictions of the bulk model using the new parameterization were tested in simulations of shallow cumulus and boundary layer stratocumulus clouds; in both cases the new parameterization matched the predictions of the explicit microphysics LES quite accurately. These results show the importance of the choice of the dataset in parameterization development and the need for it to be balanced by realistic dynamic conditions. The strong sensitivity to representation of rain evaporation is also demonstrated. Accurate formulation of this process, tuned for the case of cumulus convection, has substantially improved precision of rain production. © 2013 American Meteorological Society."
"35766462900;7006422317;6603576275;","Impact of physical parameterization schemes on numerical simulation of super cyclone Gonu",2010,"10.1007/s11069-010-9521-x","https://www.scopus.com/inward/record.uri?eid=2-s2.0-78049326382&doi=10.1007%2fs11069-010-9521-x&partnerID=40&md5=2a6efe75397bcb368a3a43edb71023bc","The objective of this study is to investigate in detail the sensitivity of cumulus, planetary boundary layer and explicit cloud microphysics parameterization schemes on intensity and track forecast of super cyclone Gonu (2007) using the Pennsylvania State University-National Center for Atmospheric Research Fifth-Generation Mesoscale Model (MM5). Three sets of sensitivity experiments (totally 11 experiments) are conducted to examine the impact of each of the aforementioned parameterization schemes on the storm's track and intensity forecast. Convective parameterization schemes (CPS) include Grell (Gr), Betts-Miller (BM) and updated Kain-Fritsch (KF2); planetary boundary layer (PBL) schemes include Burk-Thompson (BT), Eta Mellor-Yamada (MY) and the Medium-Range Forecast (MRF); and cloud microphysics parameterization schemes (MPS) comprise Warm Rain (WR), Simple Ice (SI), Mixed Phase (MP), Goddard Graupel (GG), Reisner Graupel (RG) and Schultz (Sc). The model configuration for CPS and PBL experiments includes two nested domains (90- and 30-km resolution), and for MPS experiments includes three nested domains (90-, 30- and 10-km grid resolution). It is found that the forecast track and intensity of the cyclone are most sensitive to CPS compared to other physical parameterization schemes (i. e., PBL and MPS). The simulated cyclone with Gr scheme has the least forecast track error, and KF2 scheme has highest intensity. From the results, influence of cumulus convection on steering flow of the cyclone is evident. It appears that combined effect of midlatitude trough interaction, strength of the anticyclone and intensity of the storm in each of these model forecasts are responsible for the differences in respective track forecast of the cyclone. The PBL group of experiments has less influence on the track forecast of the cyclone compared to CPS. However, we do note a considerable variation in intensity forecast due to variations in PBL schemes. The MY scheme produced reasonably better forecast within the group with a sustained warm core and better surface wind fields. Finally, results from MPS set of experiments demonstrate that explicit moisture schemes have profound impact on cyclone intensity and moderate impact on cyclone track forecast. The storm produced from WR scheme is the most intensive in the group and closer to the observed strength. The possible reason attributed for this intensification is the combined effect of reduction in cooling tendencies within the storm core due to the absence of melting process and reduction of water loading in the model due to absence of frozen hydrometeors in the WR scheme. We also note a good correlation between evolution of frozen condensate and storm intensification rate among these experiments. It appears that the Sc scheme has some systematic bias and because of that we note a substantial reduction in the rain water formation in the simulated storm when compared to others within the group. In general, it is noted that all the sensitivity experiments have a tendency to unrealistically intensify the storm at the later part of the integration phase. © 2010 Springer Science+Business Media B.V."
"22933265100;35412863900;6701378450;","Sensitivity of the global distribution of cirrus ice crystal concentration to heterogeneous freezing",2010,"10.1029/2010JD014273","https://www.scopus.com/inward/record.uri?eid=2-s2.0-78650278107&doi=10.1029%2f2010JD014273&partnerID=40&md5=526578839b3a09145afe9f42c3901bfa","This study presents the sensitivity of global ice crystal number concentration, N<inf>c</inf>, to the parameterization of heterogeneous ice nuclei (IN). Simulations are carried out with the NASA Global Modeling Initiative chemical and transport model coupled to an analytical ice microphysics parameterization. Heterogeneous freezing is described using nucleation spectra derived from theoretical considerations and empirical data for dust, black carbon, ammonium sulfate, and glassy aerosol as IN precursors. When competition between homogeneous and heterogeneous freezing is considered, global mean N<inf>c</inf> vary by up to a factor of twenty depending on the heterogeneous freezing spectrum used. IN effects on N<inf>c</inf> strongly depend on dust and black carbon concentrations and are strongest under conditions of weak updraft and high temperature. Regardless of the heterogeneous spectrum used, dust is an important contributor of IN over large regions of the Northern Hemisphere. Black carbon however exhibits appreciable effects on N<inf>c</inf> when the freezing fraction is greater than 1%. Compared to in situ observations, N<inf>c</inf> is overpredicted at temperatures below 205 K, even if a fraction of liquid aerosol is allowed to act as glassy IN. Assuming that cirrus formation is forced by weak updraft addressed this overprediction but promoted heterogeneous freezing effects to the point where homogeneous freezing is inhibited for IN concentrations as low as 1 L-1. Chemistry and dynamics must be considered to explain cirrus characteristics at low temperature. Only cloud formation scenarios where competition between homogeneous and heterogeneous freezing is the dominant feature would result in maximum supersaturation levels consistent with observations. Copyright 2010 by the American Geophysical Union."
"35089930100;7005452282;6701873414;15318900900;7203034123;6506545080;7004242319;6602681732;","Millimeter wave scattering from ice crystals and their aggregates: Comparing cloud model simulations with X- and Ka-band radar measurements",2011,"10.1029/2011JD015909","https://www.scopus.com/inward/record.uri?eid=2-s2.0-80053082019&doi=10.1029%2f2011JD015909&partnerID=40&md5=fa37400c563ada2c57ddd434f8c3da93","Arctic clouds are often mixed-phase, such that the radiative properties of the clouds are a strong function of the relative amounts of cloud liquid and ice. Modeling studies have shown that the poorly understood ice phase processes are the regulators of the liquid water fraction. However, evaluating the fidelity of the model ice parameterizations has proven to be a difficult task. This study evaluates results of different ice microphysics representations in a cloud resolving model (CRM) using cloud radar measurements. An algorithm is presented to generate realistic ice crystals and their aggregates from which radar backscattering cross sections may be calculated using a generalized solution for a cluster of spheres. The aggregate is composed of a collection of ice crystals, each of which is constructed from a cluster of tiny ice spheres. Each aggregate satisfies the constraints set by the component crystal type and the mass-dimensional relationship used in the cloud resolving model, but is free to adjust its aspect ratio. This model for calculating radar backscattering is compared to two spherical and two spheroidal (bulk model) representations for ice hydrometeors. It was found that a refined model for representing the ice hydrometeors, both pristine crystals and their aggregates, is required in order to obtain good comparisons between the CRM calculations and the radar measurements. The addition of the radar-CRM comparisons to CRM-in situ measurements comparisons allowed conclusions about the appropriateness of different CRM ice microphysics parameterizations. Copyright 2011 by the American Geophysical Union."
"7202202476;7101844867;57217500410;7102309161;","A mixed-phase cloud scheme based on a single prognostic equation",1996,"10.1034/j.1600-0870.1996.t01-3-00001.x","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0030432257&doi=10.1034%2fj.1600-0870.1996.t01-3-00001.x&partnerID=40&md5=6cb5e7783c3ea4c054630f3de3c40bee","A mixed-phase cloud scheme is proposed. It is derived by considering simplifications from cloud microphysics parameterizations currently used in cloud models. The scheme considers only one prognostic variable (the total water content) partitioned diagnostically into solid and liquid phases at subfreezing temperatures. The scheme preserves the basic microphysical processes characterizing natural mixed-phase clouds and does not include any adjustable (nonphysical) parameter. The proposed approach can be used in mesoscale or large-scale atmospheric models since it is computationally fast and easy to implement. This allows simulations that would have been otherwise impossible with more elaborate cloud microphysics schemes, because of excessive computational load. Numerical experiments with a mesoscale model have shown that mixedphase clouds generated with the scheme are confined to localized regions and are strongly correlated with the intensity of the vertical lifting. The amount of supercooled liquid water (SLW) thus obtained is substantially less than the amount obtained from other schemes using temperature as the only indicator for the appearance of mixed-phase clouds."
"56027675700;25629281900;51863379200;6505791231;7005219614;","The added value of convection permitting simulations of extreme precipitation events over the eastern Mediterranean",2017,"10.1016/j.atmosres.2017.03.002","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85015078257&doi=10.1016%2fj.atmosres.2017.03.002&partnerID=40&md5=ca7af6d03ffb1ab0b85a133ee579d1fe","Climate change is expected to substantially influence precipitation amounts and distribution. To improve simulations of extreme rainfall events, we analyzed the performance of different convection and microphysics parameterizations of the WRF (Weather Research and Forecasting) model at very high horizontal resolutions (12, 4 and 1 km). Our study focused on the eastern Mediterranean climate change hot-spot. Five extreme rainfall events over Cyprus were identified from observations and were dynamically downscaled from the ERA-Interim (EI) dataset with WRF. We applied an objective ranking scheme, using a 1-km gridded observational dataset over Cyprus and six different performance metrics, to investigate the skill of the WRF configurations. We evaluated the rainfall timing and amounts for the different resolutions, and discussed the observational uncertainty over the particular extreme events by comparing three gridded precipitation datasets (E-OBS, APHRODITE and CHIRPS). Simulations with WRF capture rainfall over the eastern Mediterranean reasonably well for three of the five selected extreme events. For these three cases, the WRF simulations improved the ERA-Interim data, which strongly underestimate the rainfall extremes over Cyprus. The best model performance is obtained for the January 1989 event, simulated with an average bias of 4% and a modified Nash-Sutcliff of 0.72 for the 5-member ensemble of the 1-km simulations. We found overall added value for the convection-permitting simulations, especially over regions of high-elevation. Interestingly, for some cases the intermediate 4-km nest was found to outperform the 1-km simulations for low-elevation coastal parts of Cyprus. Finally, we identified significant and inconsistent discrepancies between the three, state of the art, gridded precipitation datasets for the tested events, highlighting the observational uncertainty in the region. © 2017 Elsevier B.V."
"6701873215;57197049993;6507002063;7004835515;","An implicitly balanced hurricane model with physics-based preconditioning",2005,"10.1175/MWR2901.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-18544380366&doi=10.1175%2fMWR2901.1&partnerID=40&md5=3e71bf07eecaa1a9dfe813b1f002f749","A numerical framework for simulating hurricanes based upon solving a nonlinear equation set with an implicitly balanced solution procedure is described in this paper. The physical model is the Navier-Stokes equations plus a highly simplified and differentiable microphysics parameterization package. Because the method is fully implicit, the approach is able to employ time steps that result in Courant-Friedrichs-Lewy (CFL) numbers greater than one for advection, gravity, and sound waves; however, the dynamical time scale of the problem must still be respected for accuracy. The physical model is solved via the Jacobian-free Newton-Krylov (JFNK) method. The JFNK approach typically requires the approximate solution of a large linear system several times per time step. To increase the efficiency of the linear system solves, a physics-based preconditioner has been employed. To quantify the accuracy and efficiency of the new approach against traditional approaches, the implicitly balanced solver was first compared against semi-implicit approaches for the simulation of a precipitating moist bubble. The moist-bubble simulations demonstrated the ability of the implicitly balanced approach to achieve a given level of accuracy in a more efficient manner than either a first-order semi-implicit approach or a traditional leapfrog semi-implicit approach. This behavior is further illustrated in first-of-a-kind three-dimensional implicitly balanced hurricane simulations that reveal the first-order-in-time semi-implicit algorithm needs to take a time step at least 60 times smaller than the implicitly balanced algorithm to produce a comparable accuracy. © 2005 American Meteorological Society."
"7202258620;6701463335;55720332500;9239331500;8067250600;7003298573;35556482500;7003430284;","Modelling aerosol-cloud-meteorology interaction: A case study with a fully coupled air quality model (GEM-MACH)",2015,"10.1016/j.atmosenv.2015.05.062","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84939773088&doi=10.1016%2fj.atmosenv.2015.05.062&partnerID=40&md5=b29d45adc95b573f823000cb88e54176","A fully coupled on-line air quality forecast model, GEM-MACH, was used to study aerosol-cloud interactions for a case of an urban-industrial plume impacting stratocumulus. The aerosol effect on the cloud microphysics was achieved by the use of parameterization of cloud droplet nucleation predicted from the on-line size- and composition-resolved aerosols and coupled with a double-moment cloud microphysics parameterization. The model simulations with and without the on-line aerosol effect on cloud microphysics were compared and evaluated against in-situ aerosol and cloud observations from ICARTT 2004. Inclusion of the on-line aerosol interaction with cloud resulted in an increase in modelled cloud amount and cloud liquid water content (LWC) due to increased cloud droplet number concentration (Nd), a decrease in cloud droplet size and a reduction in warm precipitation. The modelled LWC and Nd agreed more closely with the observations when the on-line aerosol was allowed to affect the cloud than when aerosol effects on cloud were not explicitly simulated. The increased cloud amount due to the aerosol effects reduced the modelled downward shortwave radiative flux and air temperature at the surface, contributing to a decrease in ozone over the region of enhanced cloud and an increase in particle sulphate from an increased capacity for aqueous-phase production. Aerosol activation is shown to have a significant influence on the cloud microphysics and cloud processing of trace gases and aerosols. The importance of reasonable parameterization of cloud updraft speed is demonstrated. © 2015."
"36059595100;8511991900;7202048112;15755995900;55544607500;55476830600;36538539800;57207176515;16246205000;","Investigation of aerosol indirect effects using a cumulus microphysics parameterization in a regional climate model",2014,"10.1002/2013JD020958","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84900620563&doi=10.1002%2f2013JD020958&partnerID=40&md5=a264bc5e18113673404179e0061b28d5","A new Zhang and McFarlane (ZM) cumulus scheme includes a two-moment cloud microphysics parameterization for convective clouds. This allows aerosol effects to be investigated more comprehensively by linking aerosols with microphysical processes in both stratiform clouds that are explicitly resolved and convective clouds that are parameterized in climate models. This new scheme is implemented in the Weather Research and Forecasting model, coupled with the physics and aerosol packages from the Community Atmospheric Model version 5. A case of July 2008 during the East Asian summer monsoon is selected to evaluate the performance of the new ZM and to investigate aerosol effects on monsoon precipitation. The precipitation and radiative fluxes simulated by the new ZM show a better agreement with observations compared to simulations with the original ZM that does not include convective cloud microphysics and aerosol-convective cloud interactions. Detailed analysis suggests that an increase in detrained cloud water and ice mass by the new ZM is responsible for this improvement. Aerosol impacts on cloud properties, precipitation, and radiation are examined by reducing the primary aerosols and anthropogenic emissions to 30% of those in the present (polluted) condition. The simulated surface precipitation is reduced by 9.8% from clean to polluted environment, and the reduction is less significant when microphysics processes are excluded from the cumulus clouds. Cloud fraction is reduced by the increased aerosols due to suppressed convection, except during some heavy precipitation periods when cloud fraction, cloud top height, and rain rate are increased due to enhanced convection. © 2013. American Geophysical Union. All Rights Reserved."
"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."
"36782028900;6602418886;36659097300;6701728368;","Forecast of icing events at a wind farm in Sweden",2014,"10.1175/JAMC-D-13-09.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84897654598&doi=10.1175%2fJAMC-D-13-09.1&partnerID=40&md5=7c88e18fb09d6c28278109977ce54940","This paper introduces a method for identifying icing events using a physical icing model, driven by atmospheric data from the Weather Research and Forecasting (WRF) model, and applies it to a wind park in Sweden. Observed wind park icing events were identified by deviation from an idealized power curve and observed temperature. The events were modeled using a physical icing model with equations for both accretion and ablation mechanisms (iceBlade). The accretion model is based on the Makkonen model but was modified to make it applicable to the blades of a wind turbine rather than a static structure, and the ablation model is newly developed. The results from iceBlade are shown to outperform a 1-day persistence model and standard cylinder model in determining the times when any turbine in the wind park is being impacted by icing. The icing model was evaluated using inputs from simulations using nine different WRF physics parameterization combinations. The combination of the Thompson microphysics parameterization and version 2 of the Mellor-Yamada-Nakanishi-Niino PBL scheme was shown to perform best at this location. The distribution of cloud mass into the appropriate hydrometeor classes was found to be very important for forecasting the correct icing period. One concern with the iceBlade approach was the relatively high false alarm rates at the end of icing events due to the ice not being removed rapidly enough. © 2014 American Meteorological Society."
"55184578800;12766815800;6604020335;7006429360;6603777752;14019788700;16029532400;13407050600;","An investigation of the goshen county, wyoming, tornadic supercell of 5 june 2009 using EnKF assimilation of mobile mesonet and radar observations collected during VORTEX2. Part I: Experiment design and verification of the EnKF analyses",2014,"10.1175/MWR-D-13-00007.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84893828102&doi=10.1175%2fMWR-D-13-00007.1&partnerID=40&md5=c62d173705d41d8e61f7cbe648253c5f","High-resolution Doppler radar velocities and in situ surface observations collected in a tornadic supercell on 5 June 2009 during the second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2) are assimilated into a simulated convective storm using an ensemble Kalman filter (EnKF). A series of EnKF experiments using a 1-km horizontal model grid spacing demonstrates the sensitivity of the cold pool and kinematic structure of the storm to the assimilation of these observations and to different model microphysics parameterizations. An experiment is performed using a finer grid spacing (500m) and the most optimal data assimilation and model configurations from the sensitivity tests to produce a realistically evolving storm. Analyses from this experiment are verified against dual-Doppler and in situ observations and are evaluated for their potential to confidently evaluate mesocyclone-scale processes in the storm using trajectory analysis and calculations of Lagrangian vorticity budgets. In Part II of this study, these analyses will be further evaluated to learn the roles that mesocyclone-scale processes play in tornado formation, maintenance, and decay. The coldness of the simulated low-level outflow is generally insensitive to the choice of certain microphysical parameterizations, likely owing to the vast quantity of kinematic and in situ thermodynamic observations assimilated. The three-dimensional EnKF wind fields and parcel trajectories resemble those retrieved from dual- Doppler observations within the storm, suggesting that realistic four-dimensional mesocyclone-scale processes are captured. However, potential errors are found in trajectories and Lagrangian three-dimensional vorticity budget calculations performed within themesocyclone thatmay be due to the coarse (2min) temporal resolution of the analyses. Therefore, caution must be exercised when interpreting trajectories in this area of the storm. © 2014 American Meteorological Society."
"57217959016;6604020335;12766815800;6603777752;57214650920;","Descending reflectivity cores in supercell thunderstorms observed by mobile radars and in a high-resolution numerical simulation",2009,"10.1175/2008WAF2222116.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-66049144960&doi=10.1175%2f2008WAF2222116.1&partnerID=40&md5=34b7fdd2ae58ba2b9fca8e7c0f513a0f","This paper is motivated by the recent interest in the ""descending reflectivity cores"" (DRCs) that have been observed in some supercell thunderstorms prior to the development or intensification of low-level rotation. The DRCs of interest descend on the right rear flank of the storms and are small in scale, relative to the main radar echo. They are observed to descend from the echo overhang and, upon reaching low levels, have been found to contribute to the formation or evolution of hook echoes, which are perhaps the most familiar radar characteristic of supercells. Herein, observations of DRCs obtained by a mobile Doppler radar at close range are presented. The data afford higher-resolution views of DRCs and their accompanying radial velocity fields than typically are available from operational radars, although one drawback is that some of the larger-scale perspective is sacrificed (e.g., the origin of the DRC and its possible connection to the reflectivity near the updraft summit are within the cone of silence). It is found that it is difficult to generalize a relationship between the observations of DRCs and the subsequent evolution of the low-level wind field. The results of a three-dimensional numerical simulation of a supercell thunderstorm also are presented. DRCs are a common development within the simulation despite the use of a simple (warm rain) microphysics parameterization. The simulation allows for an investigation of the aspects of DRCs that cannot be ascertained using single-Doppler radar observations, for example, DRC formation mechanisms, the relationship between DRCs and the three-dimensional wind field, and the thermodynamic fields that accompany DRCs. Three different mechanisms are identified by which DRCs can develop in the model, not all of which are followed by increases in low-level rotation. This finding might account for the aforementioned difficulty in generalizing associations between DRCs and changes in the low-level wind field observed by mobile radar, as well as the fact that prior studies also have produced somewhat mixed results with respect to the potential of DRC detection to aid in the operational forecasting of tornadogenesis. © 2009 American Meteorological Society."
"16639418500;57203053317;","Introduction of prognostic rain in ECHAM5: Design and single column model simulations",2008,"10.5194/acp-8-2949-2008","https://www.scopus.com/inward/record.uri?eid=2-s2.0-45349102060&doi=10.5194%2facp-8-2949-2008&partnerID=40&md5=3421d2fab72d4d2a4beab5eb73ab8dc2","Prognostic equations for the rain mass mixing ratio and the rain drop number concentration are introduced into the large-scale cloud microphysics parameterization of the ECHAM5 general circulation model (ECHAM5-PROG). To this end, a rain flux from one level to the next with the appropriate fall speed is introduced. This maintains rain water in the atmosphere to be available for the next time step. Rain formation in ECHAM5-PROG is, therefore, less dependent on the autoconversion rate than the standard ECHAM5 but shifts the emphasis towards the accretion rates in accordance with observations. ECHAM5-PROG is tested and evaluated with Single Column Model (SCM) simulations for two cases: the marine stratocumulus study EPIC (October 2001) and the continental mid-latitude ARM Cloud IOP (shallow frontal cloud case &ndash; March 2000). In case of heavy precipitation events, the prognostic equations for rain hardly affect the amount and timing of precipitation at the surface in different SCM simulations because heavy rain depends mainly on the large-scale forcing. In case of thin, drizzling clouds (i.e., stratocumulus), surface precipitation is sensitive to the number of sub-time steps used in the prognostic rain scheme. Cloud microphysical quantities, such as cloud liquid and rain water within the atmosphere, are sensitive to the number of sub-time steps in both considered cases. This results from the decreasing autoconversion rate and increasing accretion rate."
"8067118800;7202899330;12645767500;","Aerosol effect on the warm rain formation process: Satellite observations and modeling",2013,"10.1002/jgrd.50043","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84877979910&doi=10.1002%2fjgrd.50043&partnerID=40&md5=85df091b8980561c71cd57d0505d26b3","This study demonstrates how aerosols influence the liquid precipitation formation process. This demonstration is provided by the combined use of satellite observations and global high-resolution model simulations. Methodologies developed to examine the warm cloud microphysical processes are applied to both multi-sensor satellite observations and aerosol-coupled global cloud-resolving model (GCRM) results to illustrate how the warm rain formation process is modulated under different aerosol conditions. The observational analysis exhibits process-scale signatures of rain suppression due to increased aerosols, providing observational evidence of the aerosol influence on precipitation. By contrast, the corresponding statistics obtained from the model show a much faster rain formation even for polluted aerosol conditions and much weaker reduction of precipitation in response to aerosol increase. It is then shown that this reduced sensitivity points to a fundamental model bias in the warm rain formation process that in turn biases the influence of aerosol on precipitation. A method of improving the model bias is introduced in the context of a simplified single-column model (SCM) that represents the cloud-to-rain water conversion process in a manner similar to the original GCRM. Sensitivity experiments performed by modifying the model assumptions in the SCM and their comparisons to satellite statistics both suggest that the auto-conversion scheme has a critical role in determining the precipitation response to aerosol perturbations and also provide a novel way of constraining key parameters in the auto-conversion schemes of global models. Key Points Satellite observation analysis of aerosol effect on precipitation Global model evaluation of aerosol effect on precipitation Proposing a way of constraining microphysics parameterizations ©2013. American Geophysical Union. All Rights Reserved."
"24081888700;7409080503;","General macro- and microphysical properties of deep convective clouds as observed by MODIS",2010,"10.1175/2009JCLI3136.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77955478282&doi=10.1175%2f2009JCLI3136.1&partnerID=40&md5=049004fa72d206921c7b8305b64e051d","Deep convective clouds (DCCs) are an important player in the climate system. In this paper the authors use remote sensing data mainly from the Moderate Resolution Imaging Spectroradiometer (MODIS) cloud product to investigate a few general cloud macro- and microphysical properties of DCCs. This investigation concentrates on the tallest convective clouds and associated thick anvils that are labeled ""deep convective clouds."" General geographical patterns of DCCs from MODIS data are consistent with previous studies. By examining statistics of optical properties of DCCs over different locations of the globe, it is found that cloud optical depth distribution for DCCs shows little interannual variability for individual regions. These distributions, however, change with geographical regions. DCC ice particle size varies with surface elevation and cloud brightness temperature. DCCs that develop over elevated areas tend to have smaller ice particles at cloud top. There is a positive correlation between ice particle size and brightness temperature. The slope of this correlation has significant regional variations, which can be explained either with a simple thermodynamic consideration or with homogeneous freezing of aerosols. The findings have important implications in studying radiation budget, ice cloud microphysics parameterization, and troposphere-stratosphere water vapor exchange. © 2010 American Meteorological Society."
"56525006400;6603699044;","Impact of microphysics parameterizations on simulations of the 27 october 2010 great Salt Lake-effect snowstorm",2015,"10.1175/WAF-D-14-00060.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84923312087&doi=10.1175%2fWAF-D-14-00060.1&partnerID=40&md5=8ed92d217c32f41c9b9a2b5f1044d15f","Simulations of moist convection at cloud-permitting grid spacings are sensitive to the parameterization of microphysical processes, posing a challenge for operational weather prediction. Here, the Weather Research and Forecasting (WRF) Model is used to examine the sensitivity of simulations of the Great Salt Lake-effect snowstorm of 27 October 2010 to the choice of microphysics parameterization (MP). It is found that the simulated precipitation from fourMP schemes varies in areal coverage, amount, and position. The Thompson scheme (THOM) verifies best against radar-derived precipitation estimates and gauge observations. The Goddard, Morrison, and WRF double-moment 6-class microphysics schemes (WDM6) produce more precipitation than THOM, with WDM6 producing the largest overprediction relative to radar-derived precipitation estimates and gauge observations. Analyses of hydrometeor mass tendencies show that WDM6 creates more graupel, less snow, and more total precipitation than the other schemes. These results indicate that the rate of graupel and snow production can strongly influence the precipitation efficiency in simulations of lake-effect storms, but further work is needed to evaluate MP-scheme accuracy across a wider range of events, including the use of aircraft- and ground-based hydrometeor sampling to validate MP hydrometeor categorization. © 2015 American Meteorological Society."
"25926762100;6701895637;56455165800;","The impact of size distribution assumptions in a bulk one-moment microphysics scheme on simulated surface precipitation and storm dynamics during a low-topped supercell case in Belgium",2011,"10.1175/2010MWR3481.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-79955158709&doi=10.1175%2f2010MWR3481.1&partnerID=40&md5=e32df8f0f67fa15008ecf794ab65d0b9","In this research the impact of modifying the size distribution assumptions of the precipitating hydrometeors in a bulk one-moment microphysics scheme on simulated surface precipitation and storm dynamics has been explored for long-lived low-topped supercells in Belgium. It was shown that weighting the largest precipitating ice species of the microphysics scheme to small graupel results in an increase of surface precipitation because of counteracting effects. On the one hand, the precipitation formation process slowed down, resulting in lower precipitation efficiency. On the other hand, latent heat release associated with freezing favored more intense storms. In contrast to previous studies finding decreased surface precipitation when graupel was present in the microphysics parameterization, storms were rather shallow in the authors' simulations. This left little time for graupel sublimation. The impact of size distribution assumptions of snow was found to be small, but more realistic size distribution assumptions of rain led to the strongest effect on surface precipitation. Cold pools shrunk because of weaker rain evaporation at the cold pool boundaries, leading to a decreased surface rain area. © 2011 American Meteorological Society."
"8977001000;7403282069;","A PDF-based microphysics parameterization for simulation of drizzling boundary layer clouds",2009,"10.1175/2009JAS2944.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-70349300424&doi=10.1175%2f2009JAS2944.1&partnerID=40&md5=1302c0ed6ed87891c37287198907c5de","Formulating the contribution of subgrid-scale (SGS) variability to microphysical processes in boundary layer and deep convective cloud parameterizations is a challenging task because of the complexity of microphysical processes and the lack of subgrid-scale information. In this study, a warm-rain microphysics parameterization that is based on a joint double-Gaussian distribution of vertical velocity, liquid water potential temperature, total water mixing ratio, and perturbation of rainwater mixing ratio is developed to simulate drizzling boundary layer clouds with a single column model (SCM). The probability distribution function (PDF) is assumed, but its parameters evolve according to equations that invoke higher-order turbulence closure. These parameters are determined from the first-, second-, and third-order moments and are then used to derive analytical expressions for autoconversion, collection, and evaporation rates. The analytical expressions show that correlation between rainwater and liquid water mixing ratios of the Gaussians enhances the collection rate whereas that between saturation deficit and rainwater mixing ratios of the Gaussians enhances the evaporation rate. Cases of drizzling shallow cumulus and stratocumulus are simulated with large-eddy simulation (LES) and SCM runs (SCM-CNTL and SCM-M): LES explicitly resolves SGS variability, SCM-CNTL parameterizes SGS variability with the PDF-based scheme, but SCM-M uses the grid-mean profiles to calculate the conversion rates of microphysical processes. SCM-CNTL can well reproduce the autoconversion, collection, and evaporation rates from LES. Comparisons between the two SCM experiments showed improvements in mean profiles of potential temperature, total water mixing ratio, liquid water, and cloud amount in the simulations considering SGS variability. A 3-week integration using the PDF-based microphysics scheme indicates that the scheme is stable for long-term simulations. © 2009 American Meteorological Society."
"6507668215;24830984400;7102018821;6506597259;","Improvements of an ice-phase microphysics parameterization for use of numerical simulations of tropical convection",1995,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-0028810524&partnerID=40&md5=70ef101be91aa583b249ea89f934233f","A commonly used bulk ice-phase microphysics parameterization was modified to more realistically simulate some of the microphysical processes that occur in tropical anvil clouds. Cloud ice growth by the Bergeron process and the associated formation of snow were revised. The characteristics of graupel were also modified in accord with a previous study. Numerical simulations of a tropical squall line demonstrate that the amount of cloud ice and the extent of anvil clouds are increased to more realistic values by the first two changes. -Authors"
"8723504500;7403282069;7103158465;7004242319;","Arctic mixed-phase clouds simulated by a cloud-resolving model: Comparison with ARM observations and sensitivity to microphysics parameterizations",2008,"10.1175/2007JAS2467.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-45849096869&doi=10.1175%2f2007JAS2467.1&partnerID=40&md5=1935a9019caa321c456f0497fe977108","Single-layer mixed-phase stratiform (MPS) Arctic clouds, which formed under conditions of large surface heat flux combined with general subsidence during a subperiod of the Atmospheric Radiation Measurement (ARM) Program's Mixed-Phase Arctic Cloud Experiment (MPACE), are simulated with a cloud-resolving model (CRM). The CRM is implemented with either an advanced two-moment [Morrison et al. (MCK)] or a commonly used one-moment [Lin et al. (LFO)] bulk microphysics scheme and a state-of-the-art radiative transfer scheme. The MCK simulation, which uses the two-moment scheme and observed aerosol size distribution and ice nulei (IN) number concentration, reproduces the magnitudes and vertical structures of cloud liquid water content (LWC), total ice water content (IWC), and number concentration and effective radius of cloud droplets as suggested by the MPACE observations. The simulation underestimates ice crystal number concentrations by an order of magnitude and overestimates effective radius of ice crystals by a factor of 2-3. The LFO experiment, which uses the one-moment scheme, produces values of liquid water path (LWP) and ice plus snow water path (ISWP) that were about 30% and 4 times, respectively, those produced by MCK. The vertical profile of IWC exhibits a bimodal distribution in contrast to the constant distribution of IWC produced in MCK and observations. A sensitivity test that uses the same ice-water saturation adjustment scheme as in LFO produces cloud properties that are more similar to the LFO simulation than MCK. The mean value of the intercept parameter of snow size spectra (Nos) from MCK is one order of magnitude smaller than that assumed in LFO. A sensitivity test that prescribes the larger LFO Nos results in 20% less LWP and 5 times larger snow water path than that in MCK. When an exponential ice size distribution replaces the gamma size distribution in MCK, the ISWP decreases by 70% but the LWP increases by 7% versus that in the MCK. Increasing the IN number concentration from the observed value of 0.16 to 3.2 L-1 forces the MPS clouds to become glaciated and dissipate, but the simulated ice number concentration agrees initially with the observations better. Physical explanations for these quantitative differences are provided. It is further shown that the differences between the LFO and MCK results are larger than those due to the estimated uncertainties in the prescribed surface fluxes. Additional observations and simulations of a variety of cases are required to further narrow down uncertainties in the microphysics schemes. © 2008 American Meteorological Society."
"24764483400;7801353107;23484340400;","How sensitive are aerosol-precipitation interactions to the warm rain representation?",2015,"10.1002/2014MS000422","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84945490310&doi=10.1002%2f2014MS000422&partnerID=40&md5=7c60b1c34e83af04bbb867bc869f0dd5","It is widely acknowledged that aerosol-cloud interactions are a major uncertainty in climate and numerical weather prediction. One of the sources of uncertainty is the sensitivity of the cloud microphysics parameterization to changes in aerosol, in particular the response of precipitation. In this work, we conduct an idealized, dynamically consistent, intercomparison of warm rain microphysics schemes to understand this source of uncertainty. The aims of this investigation are: (i) investigate how sensitive precipitation susceptibility (S0) is to cloud microphysics representation and (ii) use S0 to determine the minimum complexity of microphysics required to produce a consistent precipitation response to changes in cloud drop number concentration (Nd). The main results from this work are: (i) over a large range of liquid water path and Nd, all the bulk schemes, but particularly the single moment schemes, artificially produce rain too rapidly. Relative to a reference bin microphysics scheme, this leads to a low in-cloud S0 and impacts the evolution of S0 over time. (ii) Rain evaporation causes surface S0 from all schemes to be larger than the cloud base S0. The magnitude of the change in S0 with altitude is dependent on the scheme and the representation of the rain drop size distribution. Overall, we show that single-moment schemes produce the largest range in the sensitivity of precipitation to changes in Nd. Modifying rain production parameterization alone does not reduce this spread. Instead, increasing the complexity of the rain representation to double-moment significantly improves this behavior and the overall consistency between schemes. © 2015. The Authors."
"7407663749;8204540500;6602995068;","Time series analysis of regional climate model performance",2005,"10.1029/2004JD005046","https://www.scopus.com/inward/record.uri?eid=2-s2.0-17944377798&doi=10.1029%2f2004JD005046&partnerID=40&md5=02280d31e0c8b3fff245c7540002f88e","Four regional climate models (RegCM2, MM5/BATS, MM5/SHEELS, and MM5/OSU) were intercompared on a fairly small domain covering a relatively homogenous area in Kansas, United States, including the First International Satellite Land Surface Climatology Project (SLSCP) Field Experiment (FIFE) site. The models were integrated for a 2-year period covering 1987 and 1988. The model results are evaluated against data collected during this time period at the Konza Prairie Long-Term Ecological Research (LTER) site as well as over the summer observation periods of FIFE. The models all captured the proper qualitative behavior of the interannual variability, though the magnitudes varied considerably between models. They also found it particularly difficult to reproduce observed changes in the variance of surface variables. No model performed consistently better, with each model displaying particular strengths and weaknesses of its own. RegCM2 could be improved by including an ice phase in the cloud microphysics parameterization. MM5/BATS and MM5/SHEELS need revision of the formulation of stability dependence of the surface drag coefficients, including the coupling to the wind field, as well as using a total soil depth more representative of the area. MM5/OSU simulates too much. resistance to evapotranspiration and fails to close the energy budget. All of the models overestimate runoff and evapotranspiration during winter, creating a dry anomaly which persists throughout the following summer. Development and verification of parameterizations involved in coupling the land surface and atmospheric components of these models together is at least as important as the development and verification of each component individually. Copyright 2005 by the American Geophysical Union."
"55417497600;55173596300;57208121852;7103158465;7403077486;49861577800;","Uncertainty from the choice of microphysics scheme in convection-permitting models significantly exceeds aerosol effects",2017,"10.5194/acp-17-12145-2017","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85031315792&doi=10.5194%2facp-17-12145-2017&partnerID=40&md5=7c7b246e49120deb2c008a2db459c367","This study investigates the hydrometeor development and response to cloud droplet number concentration (CDNC) perturbations in convection-permitting model configurations. We present results from a real-data simulation of deep convection in the Congo basin, an idealised supercell case, and a warm-rain large-eddy simulation (LES). In each case we compare two frequently used double-moment bulk microphysics schemes and investigate the response to CDNC perturbations. We find that the variability among the two schemes, including the response to aerosol, differs widely between these cases. In all cases, differences in the simulated cloud morphology and precipitation are found to be significantly greater between the microphysics schemes than due to CDNC perturbations within each scheme. Further, we show that the response of the hydrometeors to CDNC perturbations differs strongly not only between microphysics schemes, but the inter-scheme variability also differs between cases of convection. Sensitivity tests show that the representation of autoconversion is the dominant factor that drives differences in rain production between the microphysics schemes in the idealised precipitating shallow cumulus case and in a subregion of the Congo basin simulations dominated by liquid-phase processes. In this region, rain mass is also shown to be relatively insensitive to the radiative effects of an overlying layer of ice-phase cloud. The conversion of cloud ice to snow is the process responsible for differences in cold cloud bias between the schemes in the Congo. In the idealised supercell case, thermodynamic impacts on the storm system using different microphysics parameterisations can equal those due to aerosol effects. These results highlight the large uncertainty in cloud and precipitation responses to aerosol in convection-permitting simulations and have important implications not only for process studies of aerosol-convection interaction, but also for global modelling studies of aerosol indirect effects. These results indicate the continuing need for tighter observational constraints of cloud processes and response to aerosol in a range of meteorological regimes. © 2017 Author(s)."
"49362613000;57203405231;7103158465;","Impact of microphysics scheme complexity on the propagation of initial perturbations",2012,"10.1175/MWR-D-12-00005.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84864859667&doi=10.1175%2fMWR-D-12-00005.1&partnerID=40&md5=cb0749c63f57cd7a2e1c04a4986e0ce2","The study of evolution characteristics of initial perturbations is an important subject in four-dimensional variational data assimilation (4DVAR) and mesoscale predictability research. This paper evaluates the impact of microphysical scheme complexity on the propagation of the perturbations in initial conditions for warm-season convections over the central United States. The Weather Research and Forecasting Model (WRF), in conjunction with four schemes of the Morrison microphysics parameterization with varying complexity, was used to simulate convective cases using grids nested to 5-kmhorizontal grid spacing. Results indicate that, on average, the four schemes show similar perturbation evolution in amplitude and spatial pattern during the first 2 h. After that, the simplified schemes introduce significant error in amplitude and spatial pattern. The simplest (liquid only) and most complex schemes show almost the same growth rate of initial perturbations with different amplitudes during 6-h forecast, suggesting that the simplest scheme does not reduce the nonlinearity in the most complex scheme. The evolution of vertical velocity and total condensates is more nonlinear than horizontal wind, temperature, and humidity, which suggest that the observations of cloud variables and vertical velocity should have a shorter time window (less than 1 h) compared to horizontal wind, temperature, and humidity observations. The simplified liquid-only microphysics scheme can be used as an acceptable substitute for the more complex one with a short time window (less than 1 h). © 2012 American Meteorological Society."
"6603333885;7003666669;","Parallel simulations of aerosol influence on clouds using cloud-resolving and single-column models",2005,"10.1029/2004JD005088","https://www.scopus.com/inward/record.uri?eid=2-s2.0-25844494139&doi=10.1029%2f2004JD005088&partnerID=40&md5=04771f6c0e262e2f6c9448422d862355","The influence of the cloud condensation nucleus (CCN) concentration on the properties of low-level clouds under the conditions observed over the north central Oklahoma on 24-25 September 1997 is examined in a series of 18-hour simulations using a single-column model (SCM) and a cloud-resolving model (CM). Both models predict higher droplet concentration, smaller droplet size, and larger liquid water path in a ""polluted"" case (CCN concentration = 1000 cm-3), than in a clean case (CCN concentration = 250 cm-3), suggesting that the first and the second indirect effects act in unison under the considered conditions. A comparison of the simulations using the SCM and CM with the same two-moment bulk microphysics parameterization highlights the dominant effect of the dynamical framework on both microphysical and macrophysical properties of modeled cloud. This effect is much stronger than the variations in each of the models resulting from changing CCN concentrations. However, the relative liquid water path sensitivity to CCN concentration is similar between the SCM and CM simulations. The CM simulations with the size-resolved and the two-moment bulk microphysical parameterization yield nearly identical structure of boundary layer. Even though these simulations are in much closer agreement with each other than they are with the SCM results, the variance from the microphysics treatment is still comparable to the effect of quadrupling CCN concentration."
"57202014408;55403457500;56458847000;7004238247;8980784000;","Simulation of a heavy rainfall event over Chennai in Southeast India using WRF: Sensitivity to microphysics parameterization",2018,"10.1016/j.atmosres.2018.04.005","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85046736798&doi=10.1016%2fj.atmosres.2018.04.005&partnerID=40&md5=a2aa9f235a2ffb23116643a826eaa3fc","Chennai City on the southeast coast of India experienced record heavy rainfall on 1 Dec 2015 during the Northeast Monsoon. In this study, numerical simulations of this event are performed using the Advanced Research and Weather Research and Forecasting (WRF-ARW) model, with a cloud-resolving grid resolution of 1 km. Five simulations are performed to study the model sensitivity to cloud microphysics parameterizations on the heavy rainfall prediction. Model results are compared with the available surface and Doppler weather radar (DWR) observations. Results show that the microphysics significantly influenced the rainfall simulation due to variation in mixing ratios of different hydrometeors and the associated dynamic and thermodynamic parameters. The Thompson scheme, followed by the Morrison scheme captured the location of maximum rainfall, its spatial distribution, and its time of occurrence in close agreement with the observations. All the other schemes simulated the event with lesser intensity and at a later time. Results suggest that the Thomson scheme captured the time evolution of different hydrometeors that led to produce the observed pattern of rainfall both spatially and temporally. It is also found that the Thompson scheme correctly produced high vertical motions associated with high instability, strong mid-level convergence and upper air divergence associated with strong cyclonic vorticity, which led to the observed feature of the intense precipitation over Chennai. © 2018"
"56063751000;6701551871;56063792300;","Simulation of a severe convective storm using a numerical model with explicitly incorporated aerosols",2017,"10.1016/j.atmosres.2017.04.037","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85018300146&doi=10.1016%2fj.atmosres.2017.04.037&partnerID=40&md5=44895f73aca1bc5505a6302f0dbece5d","Despite an important role the aerosols play in all stages of cloud lifecycle, their representation in numerical weather prediction models is often rather crude. This paper investigates the effects the explicit versus implicit inclusion of aerosols in a microphysics parameterization scheme in Weather Research and Forecasting (WRF) – Advanced Research WRF (WRF-ARW) model has on cloud dynamics and microphysics. The testbed selected for this study is a severe mesoscale convective system with supercells that struck west and central parts of Serbia in the afternoon of July 21, 2014. Numerical products of two model runs, i.e. one with aerosols explicitly (WRF-AE) included and another with aerosols implicitly (WRF-AI) assumed, are compared against precipitation measurements from surface network of rain gauges, as well as against radar and satellite observations. The WRF-AE model accurately captured the transportation of dust from the north Africa over the Mediterranean and to the Balkan region. On smaller scales, both models displaced the locations of clouds situated above west and central Serbia towards southeast and under-predicted the maximum values of composite radar reflectivity. Similar to satellite images, WRF-AE shows the mesoscale convective system as a merged cluster of cumulonimbus clouds. Both models over-predicted the precipitation amounts; WRF-AE over-predictions are particularly pronounced in the zones of light rain, while WRF-AI gave larger outliers. Unlike WRF-AI, the WRF-AE approach enables the modelling of time evolution and influx of aerosols into the cloud which could be of practical importance in weather forecasting and weather modification. Several likely causes for discrepancies between models and observations are discussed and prospects for further research in this field are outlined. © 2017 Elsevier B.V."
"7103158465;56893138500;56893881700;","Concurrent sensitivities of an idealized deep convective storm to parameterization of microphysics, horizontal grid resolution, and environmental static stability",2015,"10.1175/MWR-D-14-00271.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84943402452&doi=10.1175%2fMWR-D-14-00271.1&partnerID=40&md5=fc3fec1e5dc64ea800cda76742536a84","This study investigated the sensitivity of idealized deep convective storm simulations to microphysics parameterization, horizontal grid spacing (Δx), and environmental static stability. Three different bulk microphysics schemes in the Weather Research and Forecasting Model were tested for Δx between 0.125 and 2 km and three different environmental soundings, modified by altering static stability above 5 km. Horizontally and temporally averaged condensation and surface precipitation rates and convective updraft mass flux were sensitive to microphysics scheme and Δx for all environmental soundings. Microphysical sensitivities were similar for 0.125 < Δx < 1 km, but they varied for different soundings. Sensitivities of these quantities to Δx were less robust and varied with microphysics scheme. Other statistical convective characteristics, such as the mean updraft width and strength, exhibited similar sensitivities to Δx for all of the microphysics schemes. Microphysical sensitivities were primarily attributed to interactions between microphysics, cold pools, and dynamics that affected the spatial coverage of convective updrafts and hence the horizontally averaged convective mass flux, condensation rate, and surface precipitation. However, these linkages were less clear for the lowest convective available potential energy (CAPE) sounding, and in this case other mechanisms compensated to give a similar spatial coverage of convective updrafts even in simulations without a cold pool. For higher CAPE, there was considerable production of rimed ice from all of the microphysics schemes and its assumed characteristics, especially the fall speed, were important in explaining sensitivity via microphysical impacts on the cold pool. These results highlight the need for continued improvement in representing the production of rimed ice and its characteristics in microphysics schemes. © 2015 American Meteorological Society."
"56008055600;35345247500;55250905500;6701895937;","Analysis of a localized flash-flood event over the central Mediterranean",2016,"10.1016/j.atmosres.2016.08.007","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84982106511&doi=10.1016%2fj.atmosres.2016.08.007&partnerID=40&md5=a7328962d6135b0bfb020c7bd823d837","On 3 July 2006, an exceptionally heavy convective rainfall affected a small area in Calabria, Italy. A rainfall amount of 202 mm was recorded in 2.5 h, producing considerable damage and causing a localized flash flood. The Weather Research and Forecasting (WRF) model was used to analyze the instability present in the event and the related triggering mechanisms. The high-resolution simulation is able to correctly identify the position of the precipitation peak and to clarify the mesoscale processes involved, although it significantly underestimates the total amount of precipitation. Some sensitivity experiments confirm the importance of the choice of planetary boundary layer and microphysics parameterization schemes for a correct simulation of the event, showing a strong sensitivity to these numerical tests. Also, the need for high horizontal resolution emerges clearly: an accurate representation of the orography at small scales, is required to simulate the event in its correct location. Instability indices identified an extremely favorable environment for convection development, with very high values of CAPE and high moisture content at low levels. The low mountains near the rainfall peak play an important role in triggering the release of instability and controlling the location of rainfall; in particular, the peculiar morphology of the orography creates low-level wind convergence and provides the uplift necessary for the air parcels to reach the level of free convection. In this framework, nondimensional parameters, such as the Froude number, have been calculated to better understand the interaction of the flow with the orography. © 2016 Elsevier B.V."
"7201771183;55724460500;7202612588;","Explicit precipitation-type diagnosis from a model using a mixed-phase bulk cloud-precipitation microphysics parameterization",2016,"10.1175/WAF-D-15-0136.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84965006484&doi=10.1175%2fWAF-D-15-0136.1&partnerID=40&md5=d0bc4acd58b7a37bbe1024d69bba588d","The Rapid Refresh (RAP) and High-Resolution Rapid Refresh (HRRR), both operational at NOAA's National Centers for Environmental Prediction (NCEP) use the Thompson et al. mixed-phase bulk cloud microphysics scheme. This scheme permits predicted surface precipitation to simultaneously consist of rain, snow, and graupel at the same location under certain conditions. Here, the explicit precipitation-type diagnostic method is described as used in conjunction with the Thompson et al. scheme in the RAP and HRRR models. The postprocessing logic combines the explicitly predicted multispecies hydrometeor data and other information from the model forecasts to produce fields of surface precipitation type that distinguish between rain and freezing rain, and to also portray areas of mixed precipitation. This explicit precipitation-type diagnostic method is used with the NOAA operational RAP and HRRR models. Verification from two winter seasons from 2013 to 2015 is provided against METAR surface observations. An example of this product from a January 2015 south-central United States winter storm is also shown. © 2016 American Meteorological Society."
"57197147920;7006069664;35768178600;","Impact of parameterization of physical processes on simulation of track and intensity of tropical cyclone Nargis (2008) with WRF-NMM model",2012,"10.1100/2012/671437","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84863754888&doi=10.1100%2f2012%2f671437&partnerID=40&md5=669806341d3f694118bad40c1c4405d2","The present study is carried out to investigate the performance of different cumulus convection, planetary boundary layer, land surface processes, and microphysics parameterization schemes in the simulation of a very severe cyclonic storm (VSCS) Nargis (2008), developed in the central Bay of Bengal on 27 April 2008. For this purpose, the nonhydrostatic mesoscale model (NMM) dynamic core of weather research and forecasting (WRF) system is used. Model-simulated track positions and intensity in terms of minimum central mean sea level pressure (MSLP), maximum surface wind (10m), and precipitation are verified with observations as provided by the India Meteorological Department (IMD) and Tropical Rainfall Measurement Mission (TRMM). The estimated optimum combination is reinvestigated with six different initial conditions of the same case to have better conclusion on the performance of WRF-NMM. A few more diagnostic fields like vertical velocity, vorticity, and heat fluxes are also evaluated. The results indicate that cumulus convection play an important role in the movement of the cyclone, and PBL has a crucial role in the intensification of the storm. The combination of Simplified Arakawa Schubert (SAS) convection, Yonsei University (YSU) PBL, NMM land surface, and Ferrier microphysics parameterization schemes in WRF-NMM give better track and intensity forecast with minimum vector displacement error. © 2012 Sujata Pattanayak et al."
"55899377200;56026680000;55994651900;57021911000;57202997088;6602534418;57195561509;7006894780;","WRF-based simulation of an extreme precipitation event over the Central Himalayas: Atmospheric mechanisms and their representation by microphysics parameterization schemes",2018,"10.1016/j.atmosres.2018.07.016","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050137438&doi=10.1016%2fj.atmosres.2018.07.016&partnerID=40&md5=4a87b1c8ae7a953ede49181c3ab24559","Floods and landslides represent a major risk for the Himalayan region of Nepal and the increasing frequency of intense precipitation events during recent decades leads to an escalating exposure to hazards. A better understanding of the dynamics causing extreme rainfall events is crucial in order to improve their prediction and to minimize the associated impacts. Against the background, that the meso- and micro-scale characteristics of high intensity precipitation events in the Himalayas are not yet well understood, we investigate an extreme precipitation event that led to massive flooding and landslides in western Nepal on 14–15 Aug 2014. During the event, a maximum precipitation amount of 528 mm/24 h was observed at Chisapani station. In order to simulate the atmospheric dynamics during the event, we employ the Weather Research and Forecasting (WRF) model at convection-permitting scale. Aiming at the identification of a suitable model configuration, we conduct sensitivity experiments for 9 cloud microphysics schemes and evaluate each of them against dense network of 222 precipitation stations by means of an object-based diagnostic evaluation (MODE) technique. Subsequently, the meso- and micro-scale dynamics are investigated considering relatively better performing microphysics schemes as a reference. Our results show that the essential features of the extreme event are well simulated by WRF, although the exact location and intensity varies from scheme to scheme. Two third of the considered microphysics schemes are generally able to capture the event, with the Thompson scheme showing the best agreement with observations. The investigation of the regional circulation reveals, that the event was associated with a southward expansion of an upper-level westerly trough and a contemporaneous northward migration of the low-level monsoonal trough towards Himalayan foothills. The interaction of these two systems intensified the low-level moisture fluxes from the Arabian Sea towards the Himalayan foothills. The high atmospheric moisture content, in combination with strong sensible heating of the Indian Plains and the Himalayan foothills provoked a destabilization of the atmosphere. The strong cross barrier flow further initiated the meso-scale convective systems due to the orographic uplift at the windward Himalayan slopes. The above mentioned synoptic conditions can be considered as pre-indicators for high impact precipitation events and thus indicate a certain degree of predictability. However, our results show that the selection of an appropriate microphysics scheme is crucial for the reliable prediction of intense convective rainfall events by means of convection permitting scale NWP models. © 2018"
"25926762100;26031982400;6507121473;36676894700;25647575500;7801592570;6602472532;","Comparison of one-moment and two-moment bulk microphysics for high-resolution climate simulations of intense precipitation",2014,"10.1016/j.atmosres.2014.05.012","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84901987080&doi=10.1016%2fj.atmosres.2014.05.012&partnerID=40&md5=c689ff5ee651ecc010993de860c70acd","As high-resolution climate models become increasingly complex, it should be carefully assessed to what extent the improved physics in such models justifies the large computational cost that the complexity imposes. This paper presents a detailed sensitivity study of convective precipitation characteristics to the number of prognostic moments in bulk microphysics schemes using a high-resolution convection-resolving climate model.It is shown that 1-moment and 2-moment microphysics schemes produce more similar surface precipitation characteristics for a composite of 20 real-case convective simulations in Belgium than for many idealized studies conducted before. In the baseline 2-moment scheme, size sorting of particles is counteracted by collisional drop breakup to produce mean drop sizes that are similar to those in the 1-moment version of the scheme. Hence, fallout, evaporation and surface rain rates are very similar between the two versions of the scheme.Conversely, larger sensitivities of precipitation extremes were found to the treatment of drop breakup and the shape of the particle size distributions. Consistent with previous studies, domain-averaged and peak precipitation increased monotonically with increasing breakup equilibrium diameter Deq. Further, it is shown that a negative exponential size distribution results in excessive radar reflectivities for light rain rates. Surface precipitation and the joint distribution of reflectivity and rain rate are best reproduced by a 2-moment version of the scheme that applies gamma distributions with a diagnostic shape parameter for all particles and a large Deq. However, given the large sensitivities and uncertainties associated with collisional drop breakup and size sorting, it is likely that the full potential of improved physics in a 2-moment scheme will remain underexposed as long as these processes are not better understood. © 2014 Elsevier B.V."
"11939796800;6701439569;","Atmospheric mesoscale conditions during the Boothbay meteotsunami: a numerical sensitivity study using a high-resolution mesoscale model",2014,"10.1007/s11069-014-1055-1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84893165991&doi=10.1007%2fs11069-014-1055-1&partnerID=40&md5=29c6cee0b8c67f05d2d50511d740116f","The article aims to test the sensitivity of high-resolution mesoscale atmospheric model to fairly reproduce atmospheric processes that were present during the Boothbay Harbor meteotsunami on 28 October 2008. The simulations were performed by the Weather and Research Forecasting (WRF) model at 1-km horizontal grid spacing by varying initial conditions (ICs) and lateral boundary conditions (LBCs), nesting strategy, simulation lead time and microphysics and convective parameterizations. It seems that the simulations that used higher-resolution IC and LBC were more successful in reproduction of precipitation zone and surface pressure oscillations caused by internal gravity waves observed during the event. The results were very sensitive to the simulation lead time and to the choice of convective parameterization, while the choice of microphysics parameterization and the type of nesting strategy (one-way or two-way) was less important for reproducibility of the event. The success of the WRF model appears limited to very short-range forecasting, most advanced parameterizations, and very high-resolution grid spacing; therefore, the applicability of present atmospheric mesoscale models to future operational meteotsunami warning systems still has a lot of room for improvements. © 2014, Springer Science+Business Media Dordrecht."
"20733898400;9334234800;6602084752;","New cloud and microphysics parameterisation for use in high-resolution dynamical downscaling: Application for summer extreme temperature over Belgium",2012,"10.1002/joc.2409","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84867952981&doi=10.1002%2fjoc.2409&partnerID=40&md5=8a7b8d6aa0d1d83b28894d6e0e715586","We explore the use of high-resolution dynamical downscaling as a means to simulate extreme values of summer maximum surface air temperature over Belgium (T MAX). We use the limited area version of the ARPEGE-IFS model, ALADIN. Our approach involves a sequence of daily integrations driven by perfect boundary conditions at the lateral boundaries provided by the ERA40 reanalysis. In this study, three different recent past (1961-1990) simulations are evaluated against different station datasets: (1) 40 km spatial resolution (ALD40), (2) 10 km spatial resolution (ALD10), and (3) 4 km spatial resolution (ALR04) using a new parameterisation of deep convection, and microphysics allowing the use of ALADIN at resolutions ranging from a few tens of kilometers down to less than 4 km. The validation of ALD40 reveals a positive summer bias (2.2 °C), even though the considerable spatial resolution enhancement by a factor of 4, ALD10 reduces slightly the warm biases (1.7 °C). This warm bias on T MAX is strongly correlated with cloud cover representation. Result shows an overestimate of clear-sky occurrences by ALD10 and a developing solar radiation overestimate through the diurnal cycle, with 116 W m -2 maximum overestimate at noon. ALR04 reduces considerably the warm biases (-0.2 °C) which suggests of its ability to simulate weakly forced convective cloud in the summer over Belgium. In addition, the Generalized Pareto Distribution (GPD) of the extreme high temperatures produced by the different simulations has been compared to observations of the same period. ALD40 and ALD10 gave a GPD distribution that did not replicate the observed distribution well and, thus, overestimated the extremes. This study shows that the consistent treatment of deep convection and cloud-radiation interaction when increasing the horizontal resolution is very important when studying extremely high temperatures events. © 2011 Royal Meteorological Society."
"55123205100;36867063100;55120842000;6506008020;57214546354;","Numerical simulation of cloud burst event on August 05, 2010, over Leh using WRF mesoscale model",2012,"10.1007/s11069-012-0145-1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84861691533&doi=10.1007%2fs11069-012-0145-1&partnerID=40&md5=7e1d61639ad9b98f8158412b55fc70a1","Localized deep cumulus convective clouds have a capability of giving enormous amount of rainfall over a limited horizontal area, within a short span of time. Such types of extreme rainfall events are most common over the high elevated areas of Northern India during the Southwest monsoon season which causes widespread damage to the property and lives. Therefore, it is necessary to predict such extreme events accurately to avoid damage associated with them. The numerical mesoscale model Weather Research and Forecasting has been used to simulate the cloud burst event of Leh on August 05, 2010, so as to capture the main characteristics of the various parameters associated with this localized mesoscale phenomenon. The model has been integrated with four nested domains keeping Leh and its adjoining area as center. Two cloud microphysics parameterization schemes namely WSM3 and WSM6 have been used for the sensitivity experiments and results have been analyzed to examine the performance of both the schemes in capturing such extreme localized heavy rainfall events. Results show that the WSM6 microphysics was able to simulate the precipitation near to the observation. WSM3 microphysics simulated the location of the circulation near to the observation. In addition, the results also show that the maximum magnitudes of meridional and vertical wind as simulated with WSM3 microphysics are 12 and 4 m/s, respectively. © 2012 Springer Science+Business Media B.V."
"55232897900;36856321600;7402064802;25629055800;6507492100;","The atmospheric hydrologic cycle in the ACME v0.3 model",2018,"10.1007/s00382-017-3803-x","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85026487680&doi=10.1007%2fs00382-017-3803-x&partnerID=40&md5=431ee1df24510b874d3fd1e472cba186","We examine the global water cycle characteristics in the Accelerated Climate Modeling for Energy v0.3 model (a close relative to version 5.3 of the Community Atmosphere Model) in atmosphere-only simulations spanning the years 1980–2005. We evaluate the simulations using a broad range of observational and reanalysis datasets, examine how the simulations change when the horizontal resolution is increased from 1° to 0.25∘, and compare the simulations against models participating in the the Atmosphere Model Intercomparison Project of the 5th Coupled Model Intercomparison Project (CMIP5). Particular effort has been made to evaluate the model using the best available observational estimates and verifying model biases with additional datasets when differences are known to exist among the observations. Regardless of resolution, the model exhibits several biases: global-mean precipitation, evaporation, and precipitable water are too high, light precipitation occurs too frequently, and the atmospheric residence time of water is too short. Many of these biases are shared by the multi-model mean climate of models participating in CMIP5. The reasons behind regional biases in precipitation are discussed by examining how different fields, such as local evaporation and transport of water vapor, contribute to the bias. Although increasing the horizontal resolution does not drastically change the water cycle, it does lead to a few differences: an increase in global mean precipitation rate, an increase in the fraction of total precipitation that falls over land, more frequent heavy precipitation (&gt;30 mm day- 1), and a decrease in precipitable water. One of the most notable changes is the shift of precipitation produced by the convective parameterization to that produced by the large-scale microphysics parameterization. We analyze how changes in moisture and circulation with resolution contribute to this shift in the precipitation partitioning. Because changing horizontal resolution requires some re-tuning, the effect of that tuning was evaluated by performing an additional simulation at 1∘ but using the tunings from the 0.25∘ simulation. The evaluation shows that the more frequent heavy precipitation, the decrease in precipitable water, and the shift from convective to large-scale precipitation are predominantly due to resolution changes, while tuning changes have a major influence on the global mean precipitation and the land/ocean partitioning of precipitation. © 2017, GovernmentEmployee : [Lawrence Livermore National Laboratory]."
"57169470500;35219491500;7405273411;57169013100;57115644400;","Impacts of instrument limitations on estimated raindrop size distribution, radar parameters, and model microphysics during mei-yu season in east China",2017,"10.1175/JTECH-D-16-0225.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85019603016&doi=10.1175%2fJTECH-D-16-0225.1&partnerID=40&md5=c37a564b646842f0ed458d49d04a4750","Instrumentation limitations on measured raindrop size distributions (DSDs) and their derived relations and physical parameters are studied through a comparison of the DSD measurements during mei-yu season in east China by four collocated instruments, that is, a two-dimensional video disdrometer (2DVD), a vertically pointing Micro Rain Radar (MRR), and two laser-optical OTT Particle Size Velocity (PARSIVEL) disdrometers (first generation: OTT-1; second generation: OTT-2). Among the four instruments, the 2DVD provides the most accurate DSD and drop velocity measurements, so its measured rainfall amount has the best agreement with the reference rain gauge. Other instruments tend to miss more small drops (D < 1 mm), leading to inaccurate DSDs and a lower rainfall amount. The low rainfall estimation becomes significant during heavy rainfall. The impacts of instrument limitations on the microphysical processes (e.g., evaporation and accretion rates) and convective storm morphology are evaluated. This is important especially for mei-yu precipitation, which is dominated by a high concentration of small drops. Hence, the instrument limitations need to be taken into account in both QPE and microphysics parameterization. © 2017 American Meteorological Society."
"55626648300;8701353900;","A Lagrangian drop model to study warm rain microphysical processes in shallow cumulus",2015,"10.1002/2015MS000456","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84944906486&doi=10.1002%2f2015MS000456&partnerID=40&md5=94e1c2a7a3af395cb961b4fd09dbf1fc","In this study, we introduce a Lagrangian drop (LD) model to study warm rain microphysical processes in shallow cumulus. The approach combines Large-Eddy Simulations (LES) including a bulk microphysics parameterization with an LD model for raindrop growth. The LD model is one-way coupled with the Eulerian LES and represents all relevant rain microphysical processes such as evaporation, accretion, and selfcollection among LDs as well as dynamical effects such as sedimentation and inertia. To test whether the LD model is fit for purpose, a sensitivity study for isolated shallow cumulus clouds is conducted. We show that the surface precipitation rate and the development of the raindrop size distribution are sensitive to the treatment of selfcollection in the LD model. Some uncertainty remains for the contribution of the subgrid-scale turbulence to the relative velocity difference of a pair of LDs, which appears as a factor in the collision kernel. Sensitivities to other model parameters such as the initial multiplicity or the initial mass distribution are small. Overall, sensitivities of the LD model are small compared to the uncertainties in the assumptions of the bulk rain microphysics scheme, and the LD model is well suited for particle-based studies of raindrop growth and dynamics. This opens up the opportunity to study effects like recirculation, deviations from terminal fall velocity and other microphysical phenomena that so far were not accessible for bin, bulk, or parcel models. © 2015. The Authors."
"9239331500;7101844867;57201566230;","Predicting the snow-to-liquid ratio of surface precipitation using a bulk microphysics scheme",2012,"10.1175/MWR-D-11-00286.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84866341097&doi=10.1175%2fMWR-D-11-00286.1&partnerID=40&md5=50657d5117bb2a6382be095dbd6a3e96","Bulk microphysics parameterizations play an increasingly important role for quantitative precipitation forecasting (QPF) in operational numerical weather prediction (NWP). For wintertime, numerical prediction of snowfall amounts is done by applying an estimated snow-to-liquid ratio to the liquid-equivalent QPF from the NWP model. A method has been developed to use prognostic fields from a detailed bulk scheme to predict the instantaneous snow-to-liquid ratio of precipitating snow. By exploiting aspects of the parameterization of the large crystal/aggregate (snow) category, which allow for a prediction of the mean particle size and a corresponding realistic bulk density, combined with pristine ice and graupel fields, the total volume flux of ice-phase precipitation (excluding hail) is computed, independently from the computation of the total solid mass flux. Ultimately, the accumulated unmelted solid precipitation quantity is thus predicted without having to estimate the average snow-to-liquid ratio for a given event, as is typically done for wintertime QPF. The new technique has been implemented into the two-moment version of the Milbrandt-Yau microphysics scheme, whichwas used in a high-resolution (2.5 and 1 km)NWPmodeling systemover theVancouver- Whistler region of Canada in support of forecasting for the Vancouver 2010 Olympic and Paralympic Games. Experimental fields were produced including the instantaneous snow-to-liquid ratio and the snowfall accumulation predicted directly from the scheme using the new approach. Subjective evaluation indicates that the model can discriminate between low-density and high-density snow for instantaneous precipitation. Comparison of the predicted snow-to-liquid ratio to observed climatologies indicates that the scheme produces a realistic probability distribution."
"55717074000;7401936984;7003666669;","Evaluation of a new mixed-phase cloud microphysics parameterization with CAM3 single-column model and M-PACE observations",2007,"10.1029/2007GL031446","https://www.scopus.com/inward/record.uri?eid=2-s2.0-39049089463&doi=10.1029%2f2007GL031446&partnerID=40&md5=6c09477193924a38ce918f3d5297aff3","Most global climate models generally prescribe the partitioning of condensed water into cloud droplets and cloud ice in mixed-phase clouds according to a temperature-dependent function, which affects modeled cloud phase, cloud lifetime and radiative properties. This study evaluates a new mixed-phase cloud microphysics parameterization (for ice nucleation and water vapor deposition) against the Atmospheric Radiation Measurement (ARM) Mixed-phase Arctic Cloud Experiment (M-PACE) observations using the NCAR Community Atmospheric Model Version 3 (CAM3) single column model (SCAM). It is shown that SCAM with the new scheme produces a more realistic simulation of the cloud phase structure and the partitioning of condensed water into liquid droplets against observations during the M-PACE than the standard SCAM. A sensitivity test indicates that ice number concentration could play an important role in the simulated mixed-phase cloud microphysics, and therefore needs be realistically represented in global climate models. Copyright 2007 by the American Geophysical Union."
"7003957325;7405273411;7410372222;","On the influence of assumed drop size distribution form on radar-retrieved thunderstorm microphysics",2006,"10.1175/JAM2335.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33646255959&doi=10.1175%2fJAM2335.1&partnerID=40&md5=e6a327b46d190f4bf54a19d924a24b74","Polarimetric radar measurements are used to retrieve drop size distributions (DSD) in subtropical thunderstorms. Retrievals are made with the single-moment exponential drop size model of Marshall and Palmer driven by radar reflectivity measurements and with a two-parameter constrained-gamma drop size model that utilizes reflectivity and differential reflectivity. Results are compared with disdrometer observations. Retrievals with the constrained-gamma DSD model gave better representation of total drop concentration, liquid water content, and drop median volume diameter and better described their natural variability. The Marshall-Palmer DSD model, with a fixed intercept parameter, tended to underestimate the total drop concentration in storm cores and to overestimate significantly the concentration in stratiform regions. Rainwater contents in strong convection were underestimated by a factor of 2-3, and drop median volume diameters in stratiform rain were underestimated by 0.5 mm. To determine possible DSD model impacts on numerical forecasts, evaporation and accretion rates were computed using Kessler-type parameterizations. Rates based on the Marshall-Palmer DSD model were lower by a factor of 2-3 in strong convection and were higher by about a factor of 2 in stratiform rain than those based on the constrained-gamma model. The study demonstrates the potential of polarimetric radar measurements for improving the understanding of precipitation processes and microphysics parameterization in numerical forecast models. © 2006 American Meteorological Society."
"57154887200;7004299042;7402260605;","Precipitation parameterization in a simulated Mei-Yu front",2000,"10.3319/TAO.2000.11.2.393(A)","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0034345315&doi=10.3319%2fTAO.2000.11.2.393%28A%29&partnerID=40&md5=84972f7bc7717cd7eab51babae9ade1b","Observational and numerical studies have consistently shown the importance of latent heat release associated with frontal precipitation in the development of a Mei-Yu front. However, a systematic evaluation of precipitation parameterization in the simulation of a Mei-Yu front has been rare in the literature. In order to enhance our understanding on precipitation parameterization of Mei-Yu fronts, this study conducts numerical experiments to evaluate the performance of subgrid-scale cumulus schemes and resolvable-scale microphysics schemes to simulate the Mei-Yu frontal system on 4-5 June 1998 at grid resolutions of 45 km and 15 km, using the Penn State/NCAR mesoscale model MM5. Principal findings are summarized here. • The horizontal extent and intensity of precipitation, the partitioning of precipitation into grid-resolvable and subgrid-scale portions, the vertical thermodynamic profile in the precipitation region and the embedded mesoscale structure are extremely sensitive to the choice of cumulus parameterization schemes. This is true for both the 45-and 15-km grids. • The partitioning of precipitation into subgrid scale and resolvable scale is sensitive to the particular cumulus parameterization that is used in the model, but it is nearly the same on both the 45-and 15-km grids for a given cumulus parameterization. • The detailed ice-phase microphysical processes do not have a significant impact on the rainfall pattern on either the 45-and 15-km grids. However, the inclusion of cloud ice-snow-graupel microphysical processes increases the total surface precipitation amount by 30% compared to the amount with only warm rain processes. • Variations in the subgrid-scale cumulus parameterization have a much larger impact on the distribution and amount of Mei-Yu frontal precipitation than do variations in the resolvable-scale microphysics parameterization at mesoscale grid resolutions of 10-50 km."
"55331697200;7005650812;","An Evaluation of WRF Microphysics Schemes for Simulating the Warm-Type Heavy Rain over the Korean Peninsula",2018,"10.1007/s13143-018-0006-2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85040913417&doi=10.1007%2fs13143-018-0006-2&partnerID=40&md5=7f1df0362efd8732633b5ac589d87ac9","The Korean peninsula is the region of distinctly showing the heavy rain associated with relatively low storm height and small ice water content in the upper part of cloud system (i.e., so-called warm-type heavy rainfall). The satellite observations for the warm-type rain over Korea led to a conjecture that the cloud microphysics parameterization suitable for the continental deep convection may not work well for the warm-type heavy rainfall over the Korean peninsula. Therefore, there is a growing need to examine the performance of cloud microphysics schemes for simulating the warm-type heavy rain structures over the Korean peninsula. This study aims to evaluate the capabilities of eight microphysics schemes in the Weather Research and Forecasting (WRF) model how warm-type heavy rain structures can be simulated, in reference to the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) reflectivity measurements. The results indicate that the WRF Double Moment 6-class (WDM6) scheme simulated best the vertical structure of warm-type heavy rain by virtue of a reasonable collision-coalescence process between liquid droplets and the smallest amount of snow. Nonetheless the WDM6 scheme appears to have limitations that need to be improved upon for a realistic reflectivity structure, in terms of the reflectivity slope below the melting layer, discontinuity in reflectivity profiles around the melting layer, and overestimation of upper-level reflectivity due to high graupel content. © 2018, Korean Meteorological Society and Springer Nature B.V."
"55596887300;7003406400;7102006474;12042092500;7006592026;","Numerical framework and performance of the new multiple-phase cloud microphysics scheme in RegCM4.5: Precipitation, cloud microphysics, and cloud radiative effects",2016,"10.5194/gmd-9-2533-2016","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84979929571&doi=10.5194%2fgmd-9-2533-2016&partnerID=40&md5=ade2a44f87a163830cd95e7ad583a26d","We implement and evaluate a new parameterization scheme for stratiform cloud microphysics and precipitation within regional climate model RegCM4. This new parameterization is based on a multiple-phase one-moment cloud microphysics scheme built upon the implicit numerical framework recently developed and implemented in the ECMWF operational forecasting model. The parameterization solves five prognostic equations for water vapour, cloud liquid water, rain, cloud ice, and snow mixing ratios. Compared to the pre-existing scheme, it allows a proper treatment of mixed-phase clouds and a more physically realistic representation of cloud microphysics and precipitation. Various fields from a 10-year long integration of RegCM4 run in tropical band mode with the new scheme are compared with their counterparts using the previous cloud scheme and are evaluated against satellite observations. In addition, an assessment using the Cloud Feedback Model Intercomparison Project (CFMIP) Observational Simulator Package (COSP) for a 1-year sub-period provides additional information for evaluating the cloud optical properties against satellite data. The new microphysics parameterization yields an improved simulation of cloud fields, and in particular it removes the overestimation of upper level cloud characteristics of the previous scheme, increasing the agreement with observations and leading to an amelioration of a long-standing problem in the RegCM system. The vertical cloud profile produced by the new scheme leads to a considerably improvement of the representation of the longwave and shortwave components of the cloud radiative forcing. © Author(s) 2016."
"36443431900;","Near-ground rotation in simulated supercells: On the robustness of the baroclinic mechanism",2015,"10.1175/MWR-D-15-0115.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84957828093&doi=10.1175%2fMWR-D-15-0115.1&partnerID=40&md5=ed6e499bd984c1264bb2caf91c7bd148","This study addresses the robustness of the baroclinic mechanism that facilitates the onset of surface rotation in supercells by using two idealized simulations with different microphysics parameterizations and by considering previous results. In particular, the importance of ambient crosswise vorticity relative to baroclinically generated vorticity in the development of near-ground cyclonic vorticity is analyzed. The storms were simulated using the CM1 model in a kinematic base state characterized by a straight-line hodograph. Atrajectory analysis spanning about 30 min was performed for a large number of parcels that contribute to near-surface vertical-vorticity maxima. The vorticity along these trajectories was decomposed into barotropic and nonbarotropic parts, where the barotropic vorticity represents the effects of the preexisting, substantially crosswise horizontal storm-relative vorticity. The nonbarotropic part represents the vorticity produced baroclinically within the storm. It was found that the imported barotropic vorticity attains a downward component near the surface, while the baroclinic vorticity points upward and dominates. This dominance of the baroclinic vorticity is independent of whether a single-moment or double-moment microphysics parameterization is used. A scaling argument is offered as explanation, predicting that the baroclinic vertical vorticity becomes increasingly dominant as downdraft strength increases. © 2015 American Meteorological Society."
"56193289600;57202026995;","Ensemble hydrometeorological forecasts using WRF hourly QPF and topmodel for a middle watershed",2014,"10.1155/2014/484120","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84901788124&doi=10.1155%2f2014%2f484120&partnerID=40&md5=34672cfa9e5cf68ac7c3995e6dfe7d2c","Quantitative precipitation forecasts (QPFs) were obtained from ensembles of the weather and research forecasting (WRF) model for the Iguaçu river watershed (IRW) in southern Brazil. Thirty-two rainfall events between 2005 and 2010 were simulated with ten configurations of WRF. These rainfall events range from local to synoptic scale convection and caused a significant increase in the level of the Iguaçu river. In the average, the ensembles yielded up to 20% better skill than single WRF forecasts for the events analyzed. WRF ensembles also allow estimating the predictability through the dispersion of the forecasts providing relevant information for decision-making. Phase errors of ensemble forecasts are larger than amplitude errors. More complex microphysics parameterizations yielded better QPFs with smaller phase errors. QPFs were fed to IRW hydrological model with similar phase and amplitude errors. It is suggested that lagged QPFs might reduce phase errors. © 2014 Leonardo Calvetti and Augusto José Pereira Filho."
"56075881200;55802246600;55476830600;55688930000;56162305900;55522498000;55717074000;55087038900;","A new approach to modeling aerosol effects on East Asian climate: Parametric uncertainties associated with emissions, cloud microphysics, and their interactions",2015,"10.1002/2015JD023442","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84943457532&doi=10.1002%2f2015JD023442&partnerID=40&md5=349e540d984e83c88c34c057889dacf7","In this study, we adopt a parametric sensitivity analysis framework that integrates the quasi-Monte Carlo parameter sampling approach and a surrogate model to examine aerosol effects on the East Asian Monsoon climate simulated in the Community Atmosphere Model (CAM5). A total number of 256 CAM5 simulations are conducted to quantify the model responses to the uncertain parameters associated with cloud microphysics parameterizations and aerosol (e.g., sulfate, black carbon (BC), and dust) emission factors and their interactions. Results show that the interaction terms among parameters are important for quantifying the sensitivity of fields of interest, especially precipitation, to the parameters. The relative importance of cloud microphysics parameters and emission factors (strength) depends on evaluation metrics or the model fields we focused on, and the presence of uncertainty in cloud microphysics imposes an additional challenge in quantifying the impact of aerosols on cloud and climate. Due to their different optical and microphysical properties and spatial distributions, sulfate, BC, and dust aerosols have very different impacts on East Asian Monsoon through aerosol-cloud-radiation interactions. The climatic effects of aerosol do not always have a monotonic response to the change of emission factors. The spatial patterns of both sign and magnitude of aerosol-induced changes in radiative fluxes, cloud, and precipitation could be different, depending on the aerosol types, when parameters are sampled in different ranges of values. We also identify the different cloud microphysical parameters that show the most significant impact on climatic effect induced by sulfate, BC, and dust, respectively, in East Asia. © 2015. American Geophysical Union. All Rights Reserved."
"7005920812;23393856300;","The subgrid importance latin hypercube sampler (SILHS): A multivariate subcolumn generator",2013,"10.5194/gmd-6-1813-2013","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84887309630&doi=10.5194%2fgmd-6-1813-2013&partnerID=40&md5=2e7597561480a6e0ced8f16b749f3a31","Coarse-resolution climate and weather forecast models cannot accurately parameterize small-scale, nonlinear processes without accounting for subgrid-scale variability. To do so, some models integrate over the subgrid variability analytically. Although analytic integration methods are attractive, they can be used only with physical parameterizations that have a sufficiently simple functional form. Instead, this paper introduces a method to integrate subgrid variability using a type of Monte Carlo integration. The method generates subcolumns with suitable vertical correlations and feeds them into a microphysics parameterization. The subcolumn methodology requires little change to the parameterization source code and can be used with a wide variety of physical parameterizations. Our subcolumn generator is multivariate, which is important for physical processes that involve two or more hydrometeor species, such as accretion of cloud droplets by rain drops. In order to reduce sampling noise in the integrations, our subcolumn generator employs two variance-reduction methods, namely importance and stratified (Latin hypercube) sampling. For this reason, we name the subcolumn generator the Subgrid Importance Latin Hypercube Sampler (SILHS). This paper tests SILHS in interactive, single-column simulations of a marine stratocumulus case and a shallow cumulus case. The paper then compares simulations that use SILHS with those that use analytic integration. Although the SILHS solutions exhibit considerable noise from time step to time step, the noise is greatly damped in most of the time-averaged profiles.©Author(s) 2013."
"11940789000;7004134577;7005830548;56853406500;","The ocean-land-atmosphere model: Optimization and evaluation of simulated radiative fluxes and precipitation",2010,"10.1175/2009MWR3131.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77955582921&doi=10.1175%2f2009MWR3131.1&partnerID=40&md5=473c7878ed6ba1ab5d6631158dea11c3","This work continues the presentation and evaluation of the Ocean-Land-Atmosphere Model (OLAM), focusing on the model's ability to represent radiation and precipitation. OLAM is a new, state-of-the-art earth system model, capable of user-specified grid resolution and local mesh refinement. An objective optimization of the microphysics parameterization is carried out. Data products from the Clouds and the Earth's Radiant Energy System (CERES) and the Global Precipitation Climatology Project (GPCP) are used to construct a maximum likelihood function, and thousands of simulations using different values for key parameters are carried out. Shortwave fluxes are found to be highly sensitive to both the density of cloud droplets and the assumed shape of the cloud droplet diameter distribution function. Because there is considerable uncertainty in which values for these parameters to use in climate models, they are targeted as the tunable parameters of the objective optimization procedure, which identified high-likelihood volumes of parameter space as well as parameter uncertainties and covariances. Once optimized, the model closely matches observed large-scale radiative fluxes and precipitation. The impact of model resolution is also tested. At finer characteristic length scales (CLS), smaller-scale features such as the ITCZ are better resolved. It is also found that the Amazon was much better simulated at 100- than 200-km CLS. Furthermore, a simulation using OLAM's variable resolution functionality to cover South America with 100-km CLS and the rest of the world with 200-km CLS generates a precipitation pattern in the Amazon similar to the global 100-km CLS run. © 2010 American Meteorological Society."
"57218161877;7403282069;7004325649;7403531523;7801693068;","Statistical analyses of satellite cloud object data from CERES. Part III: Comparison with cloud-resolving model simulations of tropical convective clouds",2007,"10.1175/JAS3871.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33947389218&doi=10.1175%2fJAS3871.1&partnerID=40&md5=9aa9aedbc2375eb2d44758d41583f489","The present study evaluates the ability of a cloud-resolving model (CRM) to simulate the physical properties of tropical deep convective cloud objects identified from a Clouds and the Earth's Radiant Energy System (CERES) data product. The emphasis of this study is the comparisons among the small-, medium-, and large-size categories of cloud objects observed during March 1998 and between the large-size categories of cloud objects observed during March 1998 (strong El Niño) and March 2000 (weak La Niña). Results from the CRM simulations are analyzed in a way that is consistent with the CERES retrieval algorithm and they are averaged to match the scale of the CERES satellite footprints. Cloud physical properties are analyzed in terms of their summary histograms for each category. It is found that there is a general agreement in the overall shapes of all cloud physical properties between the simulated and observed distributions. Each cloud physical property produced by the CRM also exhibits different degrees of disagreement with observations over different ranges of the property. The simulated cloud tops are generally too high and cloud-top temperatures are too low except for the large-size category of March 1998. The probability densities of the simulated top-of-the-atmosphere (TOA) albedos for all four categories are underestimated for high albedos, while those of cloud optical depth are overestimated at its lowest bin. These disagreements are mainly related to uncertainties in the cloud microphysics parameterization and inputs such as cloud ice effective size to the radiation calculation. Summary histograms of cloud optical depth and TOA albedo from the CRM simulations of the large-size category of cloud objects do not differ significantly between the March 1998 and 2000 periods, consistent with the CERES observations. However, the CRM is unable to reproduce the significant differences in the observed cloud-top height while it overestimates the differences in the observed outgoing longwave radiation and cloud-top temperature between the two periods. Comparisons between the CRM results and the observations for most parameters in March 1998 consistently show that both the simulations and observations have larger differences between the large- and small-size categories than between the large- and medium-size, or between the medium- and small-size categories. However, the simulated cloud properties do not change as much with size as observed. These disagreements are likely related to the spatial averaging of the forcing data and the mismatch in time and space between the numerical weather prediction model from which the forcing data are produced and the CERES observed cloud systems. © 2007 American Meteorological Society."
"57205302128;","An experimental simulation of a coastal fog-stratus case using COAMPS(tm) model",2002,"10.1016/S0169-8095(02)00092-3","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036742618&doi=10.1016%2fS0169-8095%2802%2900092-3&partnerID=40&md5=25f31be2ef1c9dc34f397657de24834c","This paper presents an experimental simulation of a summer season marine fog-stratus case along the west coast of California using the US Navy COAMPS(tm) model. The purpose is to show the potential usefulness of mesoscale models in forecasting this type of marine boundary weather phenomenon. The role of data assimilation and the impacts of solar radiation, microphysics, and vertical resolution in improving the forecasts are examined. The model capability in forecasting the burn-off process over the San Francisco Bay area is also tested with very high horizontal resolution (2-km grid size) using the model's one-way nesting technique. The model demonstrates promising capacity in this case to replicate the temporal and spatial cloud coverage over the San Francisco Bay and surrounding area, shown in satellite imagery, despite a 2-h lag to complete clearing over the bay. This study also suggests that a better microphysics parameterization and proper representation of microphysics in the solar radiation scheme are both important for COAMPS(tm) to produce more realistic simulations and to improve the burn-off forecast. © 2002 Elsevier Science B.V. All rights reserved."
"55806597500;7007020349;7401513851;7102947372;","Numerical simulation of urban land surface effects on summer convective rainfall under different UHI intensity in Beijing",2017,"10.1002/2017JD026614","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85026788353&doi=10.1002%2f2017JD026614&partnerID=40&md5=22137006f062f5e86b27881457fa5e86","To investigate the effect of urban land surface on rainfall under different urban heat island intensity (UHII) conditions in Beijing, numerical simulation and sensitivity experiments on two individual summer convective rainfall events are performed, using the Weather Research and Forecasting/Noah/urban canopy model (UCM) model system. It is found that the cloud ice and cloud graupel formation processes in the microphysics parameterization scheme play a pivotal role in increasing the model’s ability to simulate convective rainfall. When UHI is weak prior to the start of rainfall, urban land surface primarily affects rainfall through its dynamic action. Rainfall systems develop a tendency to bifurcate in the windward periphery of the urban area and move around it along both sides. Consequently, precipitation in the central urban area and its downstream area decreases, whereas precipitation in the suburban areas at the sides of the periphery of the urban area increases. When UHI is strong before rainfall begins, the thermal effect of the urban land surface is the main factor that affects rainfall. The lower atmosphere over urban area is more unstable, and horizontal convergence is enhanced, increasing the intensity of the convective system after it moves to the urban area. As a result, precipitation increases in the urban area. This study demonstrates that UHII can be used as an important factor for distinguishing the effect of urban land surface on rainfall. © 2017. American Geophysical Union. All Rights Reserved."
"35766462900;7006422317;6603576275;","Impact of cloud parameterization on the numerical simulation of a super cyclone",2012,"10.5194/angeo-30-775-2012","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84860768069&doi=10.5194%2fangeo-30-775-2012&partnerID=40&md5=cfd4032f902cde179793d274309893d9","This study examines the role of parameterization of convection and explicit moisture processes on the simulated track, intensity and inner core structure of Orissa super cyclone (1999) in Bay of Bengal (north Indian Ocean). Sensitivity experiments are carried out to examine the impact of cumulus parameterization schemes (CPS) using MM5 model (Version 3.7) in a two-way nested domain (D1 and D2) configuration at horizontal resolutions (45-15 km). Three different cumulus parameterization schemes, namely Grell (Gr), Betts-Miller (BM) and updated Kain Fritsch (KF2), are tested. It is noted that track and intensity both are very sensitive to CPS and comparatively, KF2 predicts them reasonably well. Particularly, the rapid intensification phase of the super cyclone is best simulated by KF2 compared to other CPS. To examine the effect of the cumulus parameterization scheme at high resolution (5 km), the three-domain configuration (45-15-5 km resolution) is utilized. Based on initial results, KF2 scheme is used for both the domains (D1 and D2). Two experiments are conducted: one in which KF2 is used as CPS and another in which no CPS is used in the third domain. The intensity is well predicted when no CPS is used in the innermost domain. The sensitivity experiments are also carried out to examine the impact from microphysics parameterization schemes (MPS). Four cloud microphysics parameterization schemes, namely mixed phase (MP), Goddard microphysics with Graupel (GG), Reisner Graupel (RG) and Schultz (Sc), are tested in these experiments. It is noted that the tropical cyclone tracks and intensity variation have considerable sensitivity to the varying cloud microphysical parameterization schemes. The MPS of MP and Sc could very well capture the rapid intensification phase. The final intensity is well predicted by MP, which is overestimated by Sc. The MPS of GG and RG underestimates the intensity. © Author(s) 2012."
"57195922668;8511991900;42062523800;7103158465;7406215388;55723061900;7401796996;8658386900;7005742394;6603381720;9239331500;35744191200;7403077486;","Cloud-Resolving Model Intercomparison of an MC3E Squall Line Case: Part II. Stratiform Precipitation Properties",2019,"10.1029/2018JD029596","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85060791960&doi=10.1029%2f2018JD029596&partnerID=40&md5=df460873ee091cc037e209101c47b5e2","In this second part of a cloud microphysics scheme intercomparison study, we focus on biases and variabilities of stratiform precipitation properties for a midlatitude squall line event simulated with a cloud-resolving model implemented with eight cloud microphysics schemes. Most of the microphysics schemes underestimate total stratiform precipitation, mainly due to underestimation of stratiform precipitation area. All schemes underestimate the frequency of moderate stratiform rain rates (2–6 mm/hr), which may result from low-biased ice number and mass concentrations for 0.2–2-mm diameter particles in the stratiform ice region. Most simulations overestimate ice water content (IWC) at altitudes above 7 km for temperatures colder than −20 °C but produce a decrease of IWC approaching the melting level, which is opposite to the trend shown by in situ observations. This leads to general underestimations of stratiform IWC below 5-km altitude and rainwater content above 1-km altitude for a given rain rate. Stratiform precipitation area positively correlates with the convective condensate detrainment flux but is modulated by hydrometeor type, size, and fall speed. Stratiform precipitation area also changes by up to 17%–25% through alterations of the lateral boundary condition forcing frequency. Stratiform precipitation, rain rate, and area across the simulations vary by a factor of 1.5. This large variability is primarily a result of variability in the stratiform downward ice mass flux, which is highly correlated with convective condensate horizontal detrainment strength. The variability of simulated local microphysical processes in the stratiform region plays a secondary role in explaining variability in simulated stratiform rainfall properties. ©2019. The Authors."
"57190374357;18133904700;7403213622;","Impact of physical parameterizations and initial conditions on simulated atmospheric transport and CO2 mole fractions in the US Midwest",2018,"10.5194/acp-18-14813-2018","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85055105939&doi=10.5194%2facp-18-14813-2018&partnerID=40&md5=52a42b2e73b76c2dd0cd906b13d56151","<p>Atmospheric transport model errors are one of the main contributors to the uncertainty affecting CO2 inverse flux estimates. In this study, we determine the leading causes of transport errors over the US upper Midwest with a large set of simulations generated with the Weather Research and Forecasting (WRF) mesoscale model. The various WRF simulations are performed using different meteorological driver datasets and physical parameterizations including planetary boundary layer (PBL) schemes, land surface models (LSMs), cumulus parameterizations and microphysics parameterizations. All the different model configurations were coupled to CO2 fluxes and lateral boundary conditions from the CarbonTracker inversion system to simulate atmospheric CO2 mole fractions. PBL height, wind speed, wind direction, and atmospheric CO2 mole fractions are compared to observations during a month in the summer of 2008, and statistical analyses were performed to evaluate the impact of both physics parameterizations and meteorological datasets on these variables. All of the physical parameterizations and the meteorological initial and boundary conditions contribute 3 to 4ppm to the model-to-model variability in daytime PBL CO2 except for the microphysics parameterization which has a smaller contribution. PBL height varies across ensemble members by 300 to 400m, and this variability is controlled by the same physics parameterizations. Daily PBL CO2 mole fraction errors are correlated with errors in the PBL height. We show that specific model configurations systematically overestimate or underestimate the PBL height averaged across the region with biases closely correlated with the choice of LSM, PBL scheme, and cumulus parameterization (CP). Domain average PBL wind speed is overestimated in nearly every model configuration. Both planetary boundary layer height (PBLH) and PBL wind speed biases show coherent spatial variations across the Midwest, with PBLH overestimated averaged across configurations by 300-400m in the west, and PBL winds overestimated by about 1msĝ'1 on average in the east. We find model configurations with lower biases averaged across the domain, but no single configuration is optimal across the entire region and for all meteorological variables. We conclude that model ensembles that include multiple physics parameterizations and meteorological initial conditions are likely to be necessary to encompass the atmospheric conditions most important to the transport of CO2 in the PBL, but that construction of such an ensemble will be challenging due to ensemble biases that vary across the region. © Author(s) 2018."
"56651680700;7202157381;7801602398;","Dynamic downscaling over western Himalayas: Impact of cloud microphysics schemes",2018,"10.1016/j.atmosres.2017.10.007","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85033491808&doi=10.1016%2fj.atmosres.2017.10.007&partnerID=40&md5=2b168a8f21387a148f7db7c8c93ad698","Due to lack of observation data in the region of inhomogeneous terrain of the Himalayas, detailed climate of Himalayas is still unknown. Global reanalysis data are too coarse to represent the hydroclimate over the region with sharp orography gradient in the western Himalayas. In the present study, dynamic downscaling of the European Centre for Medium-Range Weather Forecast (ECMWF) Reanalysis-Interim (ERA-I) dataset over the western Himalayas using high-resolution Weather Research and Forecast (WRF) model has been carried out. Sensitivity studies have also been carried out using convection and microphysics parameterization schemes. The WRF model simulations have been compared against ERA-I and available station observations. Analysis of the results suggests that the WRF model has simulated the hydroclimate of the region well. It is found that in the simulations that the impact of convection scheme is more during summer months than in winter. Examination of simulated results using various microphysics schemes reveal that the WRF single-moment class-6 (WSM6) scheme simulates more precipitation on the upwind region of the high mountain than that in the Morrison and Thompson schemes during the winter period. Vertical distribution of various hydrometeors shows that there are large differences in mixing ratios of ice, snow and graupel in the simulations with different microphysics schemes. The ice mixing ratio in Morrison scheme is more than WSM6 above 400 hPa. The Thompson scheme favors formation of more snow than WSM6 or Morrison schemes while the Morrison scheme has more graupel formation than other schemes. © 2017 Elsevier B.V."
"7102591209;26659013400;24077600000;57190128706;24168416900;7103016965;26659116700;","The impact of two coupled cirrus microphysics-radiation parameterizations on the temperature and specific humidity biases in the tropical tropopause layer in a climate model",2016,"10.1175/JCLI-D-15-0821.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84977508616&doi=10.1175%2fJCLI-D-15-0821.1&partnerID=40&md5=97f4e10ec08a95c5c10d5f9d2a27b9f1","The impact of two different coupled cirrus microphysics-radiation parameterizations on the zonally averaged temperature and humidity biases in the tropical tropopause layer (TTL) of a Met Office climate model configuration is assessed. One parameterization is based on a linear coupling between a model prognostic variable, the ice mass mixing ratio qi, and the integral optical properties. The second is based on the integral optical properties being parameterized as functions of qi and temperature, Tc, where the mass coefficients (i.e., scattering and extinction) are parameterized as nonlinear functions of the ratio between qi and Tc. The cirrus microphysics parameterization is based on a moment estimation parameterization of the particle size distribution (PSD), which relates the mass moment (i.e., second moment if mass is proportional to size raised to the power of 2) of the PSD to all other PSD moments through the magnitude of the second moment and Tc. This same microphysics PSD parameterization is applied to calculate the integral optical properties used in both radiation parameterizations and, thus, ensures PSD and mass consistency between the cirrus microphysics and radiation schemes. In this paper, the temperature-non-dependent and temperature-dependent parameterizations are shown to increase and decrease the zonally averaged temperature biases in the TTL by about 1 K, respectively. The temperature-dependent radiation parameterization is further demonstrated to have a positive impact on the specific humidity biases in the TTL, as well as decreasing the shortwave and longwave biases in the cloudy radiative effect. The temperature-dependent radiation parameterization is shown to be more consistent with TTL and global radiation observations. © 2016 American Meteorological Society."
"45261451700;57213054025;","Multi-Physics ensemble prediction of tropical cyclone movement over Bay of Bengal",2014,"10.1007/s11069-013-0852-2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84891037778&doi=10.1007%2fs11069-013-0852-2&partnerID=40&md5=4035be3675b8ac1d1c457bd31632eded","Ensemble prediction methodology based on variations in physical process parameterizations in tropical cyclone track prediction has been assessed. Advanced Research Weather Research and Forecasting model with 30-km resolution was used to make 5-day simulation of the movement of Orissa super cyclone (1999), one of the most intense tropical cyclones over the North Indian Ocean. Altogether 36 ensemble members with all possible combinations of three cumulus convection, two planetary boundary layer and six cloud microphysics parameterization schemes were produced. A comparison of individual members indicated that Kain-Fritsch cumulus convection scheme, Mellor-Yamada-Janjic planetary boundary layer scheme and Purdue Lin cloud microphysics scheme showed better performance. The best possible ensemble formulation is identified based on SPREAD and root mean square error (RMSE). While the individual members had track errors ranging from 96-240 km at 24 h to 50-803 km at 120 h, most of the ensemble predictions show significant betterment with mean errors less than 130 km up to 120 h. The convection ensembles had large spread of the cluster, and boundary layer ensembles had significant error disparity, indicating their important roles in the movement of tropical cyclones. Six-member ensemble predictions with cloud microphysics schemes of LIN, WSM5, and WSM6 produce the best predictions with least of RMSE, and large SPREAD indicates the need for inclusion of all possible hydrometeors in the simulation and that six-member ensemble is sufficient to produce the best ensemble prediction of tropical cyclone tracks over Bay of Bengal. © 2013 Springer Science+Business Media Dordrecht."
"25823927100;7003997130;35584010200;","Impact of moisture flux and freezing level on simulated orographic precipitation errors over the Pacific Northwest",2013,"10.1175/JHM-D-12-019.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84875037877&doi=10.1175%2fJHM-D-12-019.1&partnerID=40&md5=6239b23d4e78972b49f802baf4ef08b2","Two cool seasons (November-March) of daily simulations using the fifth-generation Pennsylvania State University-NCAR Mesoscale Model (MM5) over the Pacific Northwest are used to investigate orographic precipitation bias. Model simulations are compared with data from a radiosonde site at Salem, Oregon, just upstream (west) of the Oregon Cascades; precipitation gauges over a portion of the Pacific Northwest; and a National Weather Service Weather Surveillance Radar-1988 Doppler (WSR-88D) in Portland, Oregon. The 77 storms analyzed are partitioned into warm/cold storms based on the freezing level above/below the Oregon Cascades crest (;1600 m MSL). Although the seasonal precipitation is well simulated, the model has a tendency to overpredict surface precipitation for cold storms. The correlation between the upstream relative humidity-weighted integrated moisture transport and precipitation for warm storms (r 250.81) is higher than that for cold storms (r 2 5 0.54). Comparisons of model ice water content (IWC) and derived reflectivity with radar-retrieved IWC and observed reflectivity for the 38 well-simulated storms show reasonably good agreement for warm storms but an overprediction of IWC and reflectivity aloft for cold storms. One plausible reason for the persistent overprediction of IWC in cold storms might be related to the positive bias in snow depositional growth formulation in the model bulk microphysics parameterization.Afavorable overlap of the maximumsnow depositional growth region with the mountain wave ascent region in cold storms magnifies the bias and likely contributes to the precipitation overprediction. This study also highlights the benefit of using data aloft from an operational radar to complement surface precipitation gauges for model precipitation evaluation over mountainous terrain. © 2013 American Meteorological Society."
"7405273411;55620545500;56003362600;36188558500;7202487479;57188831779;56465076800;7006640608;57205303892;56842269600;24587207000;8845741000;6507215763;7006446865;57203466193;55491523900;57190681365;7004242319;35476924900;55914072600;35320743900;7005746204;36965524800;56251200800;23491325500;57208254523;24824571400;56914807700;","Current Status and Future Challenges of Weather Radar Polarimetry: Bridging the Gap between Radar Meteorology/Hydrology/Engineering and Numerical Weather Prediction",2019,"10.1007/s00376-019-8172-4","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85064256872&doi=10.1007%2fs00376-019-8172-4&partnerID=40&md5=b66ea4d4f0c7e58d7fe9a596a7ebaa00","After decades of research and development, the WSR-88D (NEXRAD) network in the United States was upgraded with dual-polarization capability, providing polarimetric radar data (PRD) that have the potential to improve weather observations, quantification, forecasting, and warnings. The weather radar networks in China and other countries are also being upgraded with dual-polarization capability. Now, with radar polarimetry technology having matured, and PRD available both nationally and globally, it is important to understand the current status and future challenges and opportunities. The potential impact of PRD has been limited by their oftentimes subjective and empirical use. More importantly, the community has not begun to regularly derive from PRD the state parameters, such as water mixing ratios and number concentrations, used in numerical weather prediction (NWP) models. In this review, we summarize the current status of weather radar polarimetry, discuss the issues and limitations of PRD usage, and explore potential approaches to more efficiently use PRD for quantitative precipitation estimation and forecasting based on statistical retrieval with physical constraints where prior information is used and observation error is included. This approach aligns the observation-based retrievals favored by the radar meteorology community with the model-based analysis of the NWP community. We also examine the challenges and opportunities of polarimetric phased array radar research and development for future weather observation. © 2019, The Author(s)."
"55915578000;7006204393;7404970050;55574923100;6602403713;","Comparison of using distribution-specific versus effective radius methods for hydrometeor single-scattering properties for all-sky microwave satellite radiance simulations with different microphysics parameterization schemes",2017,"10.1002/2017JD026494","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85021802173&doi=10.1002%2f2017JD026494&partnerID=40&md5=bf6dcff62480e92d59c9ec4b6b5eee51","The Community Radiative Transfer Model (CRTM) presently uses one look-up table (LUT) of cloud and precipitation single-scattering properties at microwave frequencies, with which any particle size distribution may interface via effective radius. This may produce scattering properties insufficiently representative of the model output if the microphysics parameterization scheme particle size distribution mismatches that assumed in constructing the LUT, such as one being exponential and the other monodisperse, or assuming different particle bulk densities. The CRTM also assigns a 5 µ meffective radius to all nonprecipitating clouds, an additional inconsistency. Brightness temperatures are calculated from 3 h convection-permitting simulations of Hurricane Karl (2010) by the Weather Research and Forecasting model; each simulation uses one of three different microphysics schemes. For each microphysics scheme, a consistent cloud scattering LUT is constructed; the use of these LUTs produces differences in brightness temperature fields that would be better for analyzing and constraining microphysics schemes than using the CRTM LUT as-released. Other LUTs are constructed which contain one of the known microphysics inconsistencies with the CRTM LUT as-released, such as the bulk density of graupel, but are otherwise microphysics-consistent; differences in brightness temperature to using an entirely microphysics-consistent LUT further indicate the significance of that inconsistency. The CRTM LUT as-released produces higher brightness temperature than using microphysics-consistent LUTs. None of the LUTs can produce brightness temperatures that can match well to observations at all frequencies, which is likely due in part to the use of spherical particle scattering. © 2017. American Geophysical Union. All Rights Reserved."
"28568055900;7403077486;25647334300;7402942478;8418698400;7102294773;","Assessment of biomass burning smoke influence on environmental conditions for multiyear tornado outbreaks by combining aerosol-aware microphysics and fire emission constraints",2016,"10.1002/2016JD025056","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84987750226&doi=10.1002%2f2016JD025056&partnerID=40&md5=77211eaedbd37cdd71d357cbd8398870","We use the Weather Research and Forecasting (WRF) system to study the impacts of biomass burning smoke from Central America on several tornado outbreaks occurring in the U.S. during spring. The model is configured with an aerosol-aware microphysics parameterization capable of resolving aerosol-cloudradiation interactions in a cost-efficient way for numerical weather prediction (NWP) applications. Primary aerosol emissions are included, andsmokeemissions are constrained using an inverse modeling technique and satellite-based aerosol optical depth observations. Simulations turning on and off fire emissions reveal smoke presence in all tornado outbreaks being studied and show an increase in aerosol number concentrations due to smoke. However, the likelihood of occurrence and intensification of tornadoes is higher due to smoke only in cases where cloud droplet number concentration in low-level clouds increases considerably in a way that modifies the environmental conditions where the tornadoes are formed (shallower cloud basesandhigher lowlevel wind shear). Smoke absorption and vertical extent also play a role, with smoke absorption at cloud-level tending to burn-off clouds and smoke absorption above clouds resulting in an increased capping inversion. Comparing these and WRF-Chem simulations configured with a more complex representation of aerosol size and composition and different optical properties, microphysics, and activation schemes, we find similarities in terms of the simulated aerosol optical depths and aerosol impacts on near-storm environments. This provides reliability on the aerosol-aware microphysics scheme as a less computationally expensive alternative to WRF-Chem for its use in applications such as NWP and cloud-resolving simulations. © 2016. American Geophysical Union."
"25926762100;6701895637;56455165800;","Evaluation of moist processes during intense precipitation in km-scale NWP models using remote sensing and in-situ data: Impact of microphysics size distribution assumptions",2011,"10.1016/j.atmosres.2010.08.017","https://www.scopus.com/inward/record.uri?eid=2-s2.0-78649501911&doi=10.1016%2fj.atmosres.2010.08.017&partnerID=40&md5=5b1d9726fa5e67f78a68082e5e0ab437","This study investigates the sensitivity of moist processes and surface precipitation during three extreme precipitation events over Belgium to the representation of rain, snow and hail size distributions in a bulk one-moment microphysics parameterisation scheme. Sensitivities included the use of empirically derived relations to calculate the slope parameter and diagnose the intercept parameter of the exponential snow and rain size distributions and sensitivities to the treatment of hail/graupel. A detailed evaluation of the experiments against various high temporal resolution and spatially distributed observational data was performed to understand how moist processes responded to the implemented size distribution modifications. Net vapour consumption by microphysical processes was found to be unaffected by snow or rain size distribution modifications, while it was reduced replacing formulations for hail by those typical for graupel, mainly due to intense sublimation of graupel. Cloud optical thickness was overestimated in all experiments and all cases, likely due to overestimated snow amounts. The overestimation slightly deteriorated by modifying the rain and snow size distributions due to increased snow depositional growth, while it was reduced by including graupel. The latter was mainly due to enhanced cloud water collection by graupel and reduced snow depositional growth. Radar reflectivity and cloud optical thickness could only be realistically represented by inclusion of graupel during a stratiform case, while hail was found indispensable to simulate the vertical reflectivity profile and the surface precipitation structure. Precipitation amount was not much altered by any of the modifications made and the general overestimation was only decreased slightly during a supercell convective case. © 2010 Elsevier B.V."
"7005565819;","A two-step Adams-Bashforth-Moulton split-explicit integrator for compressible atmospheric models",2009,"10.1175/2009MWR2838.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-70449112405&doi=10.1175%2f2009MWR2838.1&partnerID=40&md5=219f07e5750c1d117519209bd85dc951","Split-explicit integration methods used for the compressible Navier- Stokes equations are now used in a wide variety of numerical models ranging from high-resolution local models to convection-permitting climate simulations. Models are now including more sophisticated and complicated physical processes, such as multimoment microphysics parameterizations, electrification, and dry/aqueous chemistry. A wider range of simulation problems combined with the increasing physics complexity may place a tighter constraint on the model's time step compared to the fluid flow's Courant number (e.g., the choice of the integration time step based solely on advective Courant number considerations may generate unacceptable errors associated with the parameterization schemes). The third-order multistage Runge-Kutta scheme has been very successful as the split-explicit integration method; however, its efficiency arises partially in its ability to use a time step that is 20%-40% larger than more traditional integration schemes. In applications in which the time step is constrained by other considerations, alternative integration schemes may be more efficient. Here a two-step third-order Adams-Bashforth-Moulton integrator is stably split in a similar manner as the split Runge-Kutta scheme. For applications in which the large time step is not constrained by the advective Courant number it requires less computational effort. Stability is demonstrated through eigenvalue analysis of the linear coupled one-dimensional velocity - pressure equations, and full two-dimensional nonlinear solutions from a standard test problem are shown to demonstrate solution accuracy and efficiency. © 2009 American Meteorological Society."
"55709582600;55087038900;7005453346;","Tests and improvements of GCM cloud parameterizations using the CCCMA SCM with the SHEBA data set",2006,"10.1016/j.atmosres.2005.10.009","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33749131973&doi=10.1016%2fj.atmosres.2005.10.009&partnerID=40&md5=5f61078e856bbd37c68eec40d9abe040","A GCM cloud microphysics parameterization is tested and improved using the CCCMA single-column model with cloud properties obtained at the Surface Heat Budget of the Arctic Ocean experiment (SHEBA) during the period of November 1997 to September 1998. The ECMWF reanalysis water vapor profile is scaled with rawinsonde data so that the new relative humidity profiles are compatible with rawinsonde data for nudging purposes. This study demonstrates that the treatment of ice nucleation number concentration is the controlling factor of the overestimation of monthly mean ice water path originally produced by this model. The parameterizations of accretion processes are modified to consider the accumulation due to an increase of precipitation flux through a model layer related to accretion processes. The horizontal inhomogeneity effect of cloud liquid water is considered in parameterization of autoconversion process. A new method developed for mixed-phase clouds to determine the water vapor saturation and partitioning of the condensed water into different phases is also tested in this model. When using a nudging technique with the adjusted ECMWF water vapor profile the model can well simulate the monthly total cloud cover and daily precipitation rate for the SHEBA period. Using the modified cloud microphysics parameterizations including improved treatments for accretion processes, ice nucleation number concentration, and auto-conversion, the monthly mean cloud liquid water path and ice water path are suitably simulated and compare reasonably well to those derived from measurements. © 2006 Elsevier B.V. All rights reserved."
"57154887200;6603573234;7410343982;7404117833;7403225569;8049219100;55807293800;","Ensemble prediction of rainfall during the 2000-2002 Mei-Yu seasons: Evaluation over the Taiwan area",2004,"10.1029/2003JD004368","https://www.scopus.com/inward/record.uri?eid=2-s2.0-10244237730&doi=10.1029%2f2003JD004368&partnerID=40&md5=ab19643e20d4ae605314c3a8e15f27f6","This paper reports the first effort on real-time ensemble predictions of precipitation during the 2000-2002 Mei-Yu seasons (May to June) over the Taiwan area. Six members were included, each using the fifth-generation Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model (MM5) nesting down to 15-km grid size, with different combinations of cumulus and microphysics parameterizations. Rainfall forecasts were evaluated with the equitable threat score (ETS) and bias score (BS). On the basis of verifications on 15-km grid points over three Mei-Yu seasons, it was found that no one member persistently had the least root mean square error of 12-24 hours and 24-36 hours accumulated rainfalls. For rainfall occurrence, most members had better predictions over the northeastern mountainous area, the northwestern coastal plain, the central mountain slope, the southwestern coastal plan, and the southwestern mountainous area. These regions also corresponded to areas of more accumulated rainfalls during three Mei-Yu seasons. An ensemble prediction, using a multiple linear regression (MLR) method which performed a least-square fit between the predicted and observed rainfalls in postseason analysis, had the best ETS and BS skill. The MLR ensemble forecast outperformed the average forecast (for all six members), the average forecasts of cumulus (four-member) and microphysics (three-member) ensembles, and also a high-resolution (5-km) forecast; however, a high-resolution forecast still had better skill for heavy rainfall events. The MLR ensemble forecast, using the weightings determined from previous Mei-Yu seasons, still had similar ETS trend to that with weightings determined by current-year Mei-Yu season, albeit with less skill. Copyright 2004 by the American Geophysical Union."
"25959645600;57191992819;55720588700;57191866091;57196741814;57207133453;55720539800;","Impact of Assimilating Himawari-8-Derived Layered Precipitable Water With Varying Cumulus and Microphysics Parameterization Schemes on the Simulation of Typhoon Hato",2019,"10.1029/2018JD029364","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063006653&doi=10.1029%2f2018JD029364&partnerID=40&md5=996dbbd28c85832ce8f4c2c2b6322630","Understanding moisture information ahead of tropical cyclone (TC) convection is very important for predicting TC track, intensity, and precipitation. The advanced Himawari imager onboard the Japanese Himawari-8/-9 satellite can provide high spatial and temporal resolution moisture information. Three-layered precipitable water (LPW) with its three water vapor absorption infrared bands can be assimilated to generate better understanding and prediction of TC evolution. The impacts of LPW assimilation in the Weather Research and Forecasting model with nine combinations of physical parameterization schemes, including three cumulus parameterization (CP) and three microphysics parameterization (MP) schemes on TC prediction, have been comprehensively analyzed using Typhoon Hato as a case study. The results indicate that LPW assimilation reduces the average track error and speed up TC movement by better adjustment of the atmospheric circulation fields via changing the vertical structure of moisture and thermal profile. The track forecasts retain sensitivity to CP schemes after LPW assimilation. Also, LPW assimilation improves TC intensity prediction because the latent heat release process is accurately adjusted. It has been revealed that LPW assimilation can weaken the intensity sensitivity to MP schemes more than to CP schemes. Skill scores were used to evaluate precipitation forecasts after Hato's landfall. The results indicate that heavy precipitation forecasts are more sensitive to the choice of MP schemes. After LPW assimilation, the equitable threat scores among different results become similar and all forecast skills are increased. In addition, group statistic results with different initial time show the same conclusions. ©2019. American Geophysical Union. All Rights Reserved."
"16242031400;56525113200;57189055615;","Using an object-based approach to quantify the spatial structure of reflectivity regions in Hurricane Isabel (2003). Part I: Comparisons between radar observations and model simulations",2018,"10.1175/MWR-D-17-0077.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047103168&doi=10.1175%2fMWR-D-17-0077.1&partnerID=40&md5=27f12539890adf833f803f46794a8f45","When a hurricane undergoes extratropical transition (ET), its rainbands evolve from a circular and compact shape to a more elongated, fragmented, and dispersed configuration with an exposed circulation center. This study calculates five metrics to measure these spatial changes in reflectivity regions as Hurricane Isabel (2003) underwent ET. A mosaic of observations from the Weather Surveillance Radar-1988 Doppler (WSR-88D) network is compared to reflectivity simulated by the Advanced Research Weather Research and Forecasting (WRF-ARW) Model. Six simulations are performed by varying the cumulus and microphysics parameterizations to produce a range of reflectivity configurations. A bias correction is applied to model-simulated reflectivity prior to the calculation of spatial metrics because lower reflectivity values are generally underrepresented, while higher values are generally overrepresented. However, the simulation with Kain-Fritsch cumulus and Morrison two-moment microphysics overpredicts reflectivity by 3-4 dBZ at all levels. We demonstrate that the spatial metrics effectively capture structural changes as reflectivity regions became more fragmented and dispersed and the center became more exposed. In this case study, the results were more sensitive to the choice of cumulus physics, compared with the choice of microphysics. The Kain-Fritsch simulations produce shapes that are too circular and solid when compared with WSR-88D observations, as the hurricanes lack distinct outer rainbands. Simulations with Tiedtke cumulus produce an elongated main reflectivity region as in WSR-88D, but with separate inner and outer rainbands that are too dispersed and fragmented. These results demonstrate the value in measuring spatial patterns rather than assessing model performance using visual inspection alone. © 2018 American Meteorological Society."
"57195327788;42062523800;7003926380;7003535385;12800966700;8657166100;7101638860;6701754792;","A ubiquitous ice size bias in simulations of tropical deep convection",2017,"10.5194/acp-17-9599-2017","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85027151353&doi=10.5194%2facp-17-9599-2017&partnerID=40&md5=139c21d6f2396a4579ccba7100be0ad4","The High Altitude Ice Crystals - High Ice Water Content (HAIC-HIWC) joint field campaign produced aircraft retrievals of total condensed water content (TWC), hydrometeor particle size distributions (PSDs), and vertical velocity (w) in high ice water content regions of mature and decaying tropical mesoscale convective systems (MCSs). The resulting dataset is used here to explore causes of the commonly documented high bias in radar reflectivity within cloud-resolving simulations of deep convection. This bias has been linked to overly strong simulated convective updrafts lofting excessive condensate mass but is also modulated by parameterizations of hydrometeor size distributions, single particle properties, species separation, and microphysical processes. Observations are compared with three Weather Research and Forecasting model simulations of an observed MCS using different microphysics parameterizations while controlling for w, TWC, and temperature. Two popular bulk microphysics schemes (Thompson and Morrison) and one bin microphysics scheme (fast spectral bin microphysics) are compared. For temperatures between -10 and -40 °C and TWC &gt; 1 g m-3, all microphysics schemes produce median mass diameters (MMDs) that are generally larger than observed, and the precipitating ice species that controls this size bias varies by scheme, temperature, and w. Despite a much greater number of samples, all simulations fail to reproduce observed high-TWC conditions (&gt; 2 g m-3) between -20 and -40 °C in which only a small fraction of condensate mass is found in relatively large particle sizes greater than 1 mm in diameter. Although more mass is distributed to large particle sizes relative to those observed across all schemes when controlling for temperature, w, and TWC, differences with observations are significantly variable between the schemes tested. As a result, this bias is hypothesized to partly result from errors in parameterized hydrometeor PSD and single particle properties, but because it is present in all schemes, it may also partly result from errors in parameterized microphysical processes present in all schemes. Because of these ubiquitous ice size biases, the frequently used microphysical parameterizations evaluated in this study inherently produce a high bias in convective reflectivity for a wide range of temperatures, vertical velocities, and TWCs. © 2017 Author(s)."
"7402379980;7102080550;35351704600;9239331500;36976449700;","Sensitivity of real-data simulations of the 3 May 1999 Oklahoma City tornadic supercell and associated tornadoes to multimoment microphysics. Part II: Analysis of buoyancy and dynamic pressure forces in simulated tornado-like vortices",2016,"10.1175/JAS-D-15-0114.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84962321540&doi=10.1175%2fJAS-D-15-0114.1&partnerID=40&md5=9be597fd61179878548e1de534e52e48","Vortex stretching by intense upward accelerations is a critical process for tornadogenesis and maintenance. Two high-resolution (250-m grid spacing) real-data simulations of the 3 May 1999 Oklahoma City, Oklahoma, supercell and associated tornadoes, using single- and triple-moment microphysics parameterization schemes, respectively, are examined. Microphysical, thermodynamic, and dynamic impacts on the vertical accelerations near and within simulated tornado-like vortices (TLVs) are analyzed. Systematic differences in behavior of the TLVS between the two experiments are found; the TLV in the triple-moment simulation is substantially more intense and longer lived than in the single-moment case. The triple-moment scheme in this case produces less rain and hail mass in the low levels and drop size distributions of rain shifted toward larger drops, relative to the single-moment scheme, leading to less latent cooling and warmer outflow. Trajectory analyses reveal that more parcels entering the TLV in the triple-moment simulation have a history of dynamically induced descent, whereas buoyantly driven descent is more prevalent in the single-moment experiment. It is found that the intensity and longevity of the TLV are tied to weaker negative or neutral thermal buoyancy in the air flowing into the TLV in the triple-moment case, consistent with previous observational and modeling studies. Finally, the contribution to buoyancy from pressure perturbations is found to be of prime importance within the TLV, where strong negative pressure perturbations lead to substantial positive buoyancy. This contribution compensates for the slight negative thermal buoyancy and negative dynamic pressure gradient acceleration in the triple-moment case. © 2016 American Meteorological Society."
"56612060700;6603576275;","Effect of physical parameterization schemes on track and intensity of cyclone LAILA using WRF model",2015,"10.1007/s13143-015-0071-8","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84940650254&doi=10.1007%2fs13143-015-0071-8&partnerID=40&md5=3f7ba8f7c2a742d7f382b8acc625b7ba","The objective of the present study is to investigate in detail the sensitivity of cumulus parameterization (CP), planetary boundary layer (PBL) parameterization, microphysics parameterization (MP) on the numerical simulation of severe cyclone LAILA over Bay of Bengal using Weather Research & Forecasting (WRF) model. The initial and boundary conditions are supplied from GFS data of 1° × 1° resolution and the model is integrated in three ‘twoway’ interactive nested domains at resolutions of 60 km, 20 km and 6.6 km. Total three sets of experiments are performed. First set of experiments include sensitivity of Cumulus Parameterization (CP) schemes, while second and third set of experiments is carried out to check the sensitivity of different PBL and Microphysics Parameterization (MP) schemes. The fourth set contains initial condition sensitivity experiments. For first three sets of experiments, 0000 UTC 17 May 2010 is used as initial condition. In CP sensitivity experiments, the track and intensity is well simulated by Betts-Miller-Janjic (BMJ) schemes. The track and intensity of LAILA is very sensitive to the representation of large scale environmental flow in CP scheme as well as to the initial vertical wind shear values. The intensity of the cyclone is well simulated by YSU scheme and it depends upon the mixing treatment in and above PBL. Concentration of frozen hydrometeors, such as graupel in WSM6 MP scheme and latent heat released during auto conversion of hydrometeors may be responsible for storm intensity. An additional set of experiments with different initial vortex intensity shows that, small differences in the initial wind fields have profound impact on both track and intensity of the cyclone. The representation of the mid-tropospheric heating in WSM6 is mainly controlled by amount of graupel hydrometeor and thus might be one of the possible causes in modulating the storm’s intensity. © 2015, Korean Meteorological Society and Springer Science+Business Media Dordrecht."
"57212350989;23980083200;35606965700;","Calculation of the Lightning Potential Index and electric field in numerical weather prediction models",2015,"10.1134/S0001433815010028","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84929659144&doi=10.1134%2fS0001433815010028&partnerID=40&md5=9fdfb6a482b04acb1f238c84e00f6fc9","Modern methods for predicting thunderstorms and lightnings with the use of high-resolution numerical models are considered. An analysis of the Lightning Potential Index (LPI) is performed for various microphysics parameterizations with the use of the Weather Research and Forecasting (WRF) model. The maximum index values are shown to depend significantly on the type of parameterization. This makes it impossible to specify a single threshold LPI for various parameterizations as a criterion for the occurrence of lightning flashes. The topographic LPI maps underestimate the sizes of regions of likely thunderstorm-hazard events. Calculating the electric field under the assumption that ice and graupel are the main charge carriers is considered a new algorithm of lightning prediction. The model shows that the potential difference (between the ground and cloud layer at a given altitude) sufficient to generate a discharge is retained in a larger region than is predicted by the LPI. The main features of the spatial distribution of the electric field and potential agree with observed data. © 2015, Pleiades Publishing, Ltd."
"7102743829;6506537159;","A PDF-based microphysics parameterization for shallow cumulus clouds",2014,"10.1175/JAS-D-13-0193.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84896782736&doi=10.1175%2fJAS-D-13-0193.1&partnerID=40&md5=fd841c267127ba8b0e8401cf62bc9d53","Unbiased calculations of microphysical process rates such as autoconversion and accretion in mesoscale numerical weather prediction models require that subgrid-scale (SGS) variability over the model grid volume be taken into account. This variability can be expressed as probability distribution functions (PDFs) of microphysical variables.Using dynamically balanced large-eddy simulation (LES)model results froma case ofmarine trade cumulus, the authors develop PDFs of the cloud water, droplet concentration, and rainwater variables (qc, Nc, and qr). Both 1Dand 2Djoint PDFs (JPDFs) are presented. The authors demonstrate that accounting for the JPDFs results inmore accurate process rates for a regional-model grid size. Bias in autoconversion and accretion rates are presented, assuming different formulations of the JPDFs. Approximating the 2D PDF using a product of individual 1D PDFs overestimates the autoconversion rates by an order of magnitude, whereas neglecting the SGS variability altogether results in a drastic underestimate of the grid-mean autoconversion rate. PDF assumptions have a much smaller impact on accretion, largely because of the near-linear dependence of the variables in the accretion rate formula and the relatively weak correlation between qc and qr over the small LES grid volumes. The latter is attributed to the spatial decorrelation in the vertical between the two fields. Although the full PDFs are both height and time dependent, results suggest that fixed-in-time and fixed-in-height PDFs give an acceptable level of accuracy, especially for the crucial autoconversion calculation. © 2014 American Meteorological Society."
"50061662300;57194285850;56050130600;56264494100;","Effect of cumulus and microphysical parameterizations on the JAL cyclone prediction",2014,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-84894670641&partnerID=40&md5=07bfa04b401bf92b6408ecfe1798777c","Weather Research and Forecasting (WRF) model is used to predict the track and intensity of JAL cyclone, which formed during 04-08 November 2010 over the Bay of Bengal. The model has been simulated with numerous experiments using the logical/scientific combination of convection and micro-physics schemes. The model simulations have been conducted with different initial conditions to know the effective track and intensity prediction of JAL cyclone. In addition, the effect of cumulus parameterization schemes at different resolution (27 and 9 km) on the cyclone track and intensity is reported. The model simulated results showed the importance of cumulus schemes and their role at 9 km horizontal resolution. The results indicate that the track predicted by Kain-Fritsch (KF) scheme is in good agreement with the observed track in all the experiments and the land fall error is minimum (~11 km) for the combination of Ferrier and KF scheme with 0000 hrs UTC on 04 November 2010 as initial condition. Strong intensity is produced by KF, New Grell (NG) schemes and weak intensity is produced by Betts-Miller-Janjic (BMJ) scheme with all microphysics parameterization (MP) combinations. Further, the dependency of intensity of cyclone has been studied in terms of surface latent heat flux, divergence and vorticity fields. To validate the model performance, different meteorological parameters are derived from the model simulations over three different regions and are compared with the observed meteorological parameters. The model results are in good agreement with the observed parameters, but variations are observed at the landfall /dissipation of the cyclone."
"55834717600;8535697200;7202057166;7005729142;7403077486;","Numerical Modeling of Ice Fog in Interior Alaska Using the Weather Research and Forecasting Model",2014,"10.1007/s00024-013-0766-7","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84908087725&doi=10.1007%2fs00024-013-0766-7&partnerID=40&md5=ed6cb8e41f44f7cb53aa8c86cb4bd34c","An ice microphysics parameterization scheme has been modified to better describe and understand ice fog formation. The modeling effort is based on observations in the Sub-Arctic Region of Interior Alaska, where ice fog occurs frequently during the cold season due to abundant water vapor sources and strong inversions existing near the surface at extremely low air temperatures. The microphysical characteristics of ice fog are different from those of other ice clouds, implying that the microphysical processes of ice should be changed in order to generate ice fog particles. Ice fog microphysical characteristics were derived with the NCAR Video Ice Particle Sampler during strong ice fog cases in the vicinity of Fairbanks, Alaska, in January and February 2012. To improve the prediction of ice fog in the Weather Research and Forecasting model, observational data were used to change particle size distribution properties and gravitational settling rates, as well as to implement a homogeneous freezing process. The newly implemented homogeneous freezing process compliments the existing heterogeneous freezing scheme and generates a higher number concentration of ice crystals than the original Thompson scheme. The size distribution of ice crystals is changed into a Gamma distribution with the shape factor of 2.0, using the observed size distribution. Furthermore, gravitational settling rates are reduced for the ice crystals since the crystals in ice fog do not precipitate in a similar manner when compared to the ice crystals of cirrus clouds. The slow terminal velocity plays a role in increasing the time scale for the ice crystals to settle to the surface. Sensitivity tests contribute to understanding the effects of water vapor emissions as an anthropogenic source on the formation of ice fog. © 2014, Springer Basel."
"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."
"15069126500;15069732800;57217958201;57210717445;35302065900;35461763400;","Small-scale mixing processes enhancing troposphere-to-stratosphere transport by pyro-cumulonimbus storms",2007,"10.5194/acp-7-5945-2007","https://www.scopus.com/inward/record.uri?eid=2-s2.0-36849036389&doi=10.5194%2facp-7-5945-2007&partnerID=40&md5=4c18c693fa584476bc50487493b6e769","Deep convection induced by large forest fires is an efficient mechanism for transport of aerosol particles and trace gases into the upper troposphere and lower stratosphere (UT/LS). For many pyro-cumulonimbus clouds (pyroCbs) as well as other cases of severe convection without fire forcing, radiometric observations of cloud tops in the thermal infrared (IR) reveal characteristic structures, featuring a region of relatively high brightness temperatures (warm center) surrounded by a U-shaped region of low brightness temperatures. We performed a numerical simulation of a specific case study of pyroCb using a non-hydrostatic cloud resolving model with a two-moment cloud microphysics parameterization and a prognostic turbulence scheme. The model is able to reproduce the thermal IR structure as observed from satellite radiometry. Our findings establish a close link between the observed temperature pattern and small-scale mixing processes atop and downwind of the overshooting dome of the pyroCb. Such small-scale mixing processes are strongly enhanced by the formation and breaking of a stationary gravity wave induced by the overshoot. They are found to increase the stratospheric penetration of the smoke by up to almost 30 K and thus are of major significance for irreversible transport of forest fire smoke into the lower stratosphere."
"14325652800;56537237200;57210444058;57202388328;57210443247;57209825217;57210450987;14325919500;","The impact of microphysics parameterization in the simulation of two convective rainfall events over the central Andes of Peru using WRF-ARW",2019,"10.3390/atmos10080442","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85070781090&doi=10.3390%2fatmos10080442&partnerID=40&md5=4f68bd906190a1d7e439e4a210e5ac39","The present study explores the cloud microphysics (MPs) impact on the simulation of two convective rainfall events (CREs) over the complex topography of Andes mountains, using the Weather Research and Forecasting- Advanced Research (WRF-ARW) model. The events occurred on December 29 2015 (CRE1) and January 7 2016 (CRE2). Six microphysical parameterizations (MPPs) (Thompson, WSM6, Morrison, Goddard, Milbrandt and Lin) were tested, which had been previously applied in complex orography areas. The one-way nesting technique was applied to four domains, with horizontal resolutions of 18, 6, and 3 km for the outer ones, in which cumulus and MP parameterizations were applied, while for the innermost domain, with a resolution of 0.75 km, only MP parameterization was used. It was integrated for 36 h with National Centers for Environmental Prediction (NCEP Final Operational Global Analysis (NFL) initial conditions at 00:00 UTC (Coordinated Universal Time). The simulations were verified using Geostationary Operational Environmental Satellites (GOES) brightness temperature, Ka band cloud radar, and surface meteorology variables observed at the Huancayo Observatory. All the MPPs detected the surface temperature signature of the CREs, but for CRE2, it was underestimated during its lifetime in its vicinity, matching well after the simulated event. For CRE1, all the schemes gave good estimations of 24 h precipitation, but for CRE2, Goddard and Milbrandt underestimated the 24 h precipitation in the inner domain. The Morrison and Lin configurations reproduced the general dynamics of the development of cloud systems for the two case studies. The vertical profiles of the hydrometeors simulated by different schemes showed significant differences. The best performance of the Morrison scheme for both case studies may be related to its ability to simulate the role of graupel in precipitation formation. The analysis of the maximum reflectivity field, cloud top distribution, and vertical structure of the simulated cloud field also shows that the Morrison parameterization reproduced the convective systems consistently with observations. © 2019 by the authors."
"6604020335;12766815800;","Large sensitivity of near-surface vertical vorticity development to heat sink location in idealized simulations of supercell-like storms",2017,"10.1175/JAS-D-16-0372.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85016734019&doi=10.1175%2fJAS-D-16-0372.1&partnerID=40&md5=27095f54b94928a5c88f245ed7bd8bf5","In idealized numerical simulations of supercell-like ""pseudostorms"" generated by a heat source and sink in a vertically sheared environment, a tornado-like vortex develops if air possessing large circulation about a vertical axis at the lowest model levels can be converged. This is most likely to happen if the circulation-rich air possesses only weak negative buoyancy (the circulation-rich air has a history of descent, so typically possesses at least some negative buoyancy) and is subjected to an upward-directed vertical perturbation pressure gradient force. This paper further explores the sensitivity of the development of near-surface vertical vorticity to the horizontal position of the heat sink. Shifting the position of the heat sink by only 2-3 km can significantly influence vortex intensity by altering both the baroclinic generation of circulation and the buoyancy of circulation-rich air. Many of the changes in the pseudostorms that arise from shifting the position of the heat sink would be difficult to anticipate. The sensitivity of the pseudostorms to heat sink position probably at least partly explains the well-known sensitivity of near-surface vertical vorticity development to the microphysics parameterizations in more realistic supercell storm simulations, as well as some of the failures of actual supercells to produce tornadoes in seemingly favorable environments. © 2017 American Meteorological Society."
"7003961165;","Implementation of the WSM5 and WSM6 Single Moment Microphysics Scheme into the RAMS Model: Verification for the HyMeX-SOP1",2016,"10.1155/2016/5094126","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84973137904&doi=10.1155%2f2016%2f5094126&partnerID=40&md5=bacb3e319081192cb6c055416e4c6b5d","This paper shows the results of the implementation of two widely used bulk microphysics parameterizations (BMP) into the Regional Atmospheric Modeling System to improve the Quantitative Precipitation Forecast (QPF). The schemes are the WSM5 and WSM6 (WRF-single-moment-microphysics classes 5 and 6). The RAMS is run at high horizontal resolution (4 km) over the whole Italian territory and, to mimic the operational context, it is initialized by the analysis/forecast cycle issued at 12 UTC by the European Centre for Medium Weather Range Forecast (ECMWF). The performance of the BMP is analysed for the period of September 11 to October 31, 2012, which span most of the Special Observing Period 1 (SOP1) of the hydrological cycle in the Mediterranean experiment (HyMeX). For this period a database of daily precipitation of thousands of rain gauges over the Italian territory is available. In SOP1 few hazardous events occurred over Italy and, for one of them, the model performance is shown in detail. The potential improvement gained by combining the model outputs with different BMP in a single forecast is finally explored. © 2016 Stefano Federico."
"26632168400;55795535700;7006303509;35494005000;","Perturbed physics ensemble simulations of cirrus on the cloud system-resolving scale",2014,"10.1002/2013JD020709","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84900552486&doi=10.1002%2f2013JD020709&partnerID=40&md5=f60c12699ab4b688514e4e7a77467360","In this study, the effect of uncertainties in the parameterization of ice microphysical processes and initial conditions on the variability of cirrus microphysical and radiative properties are investigated in a series of cloud system-resolving perturbed physics ensemble (PPE) and initial condition ensemble (ICE) simulations. Three cirrus cases representative of midlatitude, subtropical, and tropical anvil cirrus are examined. The variability in cirrus properties induced by perturbing uncertain parameters in ice microphysics parameterizations outweighs the variability induced by perturbing the initial conditions in midlatitude and subtropical cirrus. However, in tropical anvil cirrus the variability spanned by the PPE and ICE simulations is on the same order of magnitude. Uncertainties in the parameterization of ice microphysical processes affect the vertical distribution of cloud fraction, ice water content, and cloud thickness, whereas cirrus cloud cover is only marginally affected. The top three uncertainties controlling the microphysical variability and radiative impact of cirrus clouds are the mode of ice nucleation, the number concentrations of ice nuclei available for heterogeneous freezing, and the threshold size of the parameterized ice autoconversion process. Uncertainties in ice fall speeds are of minor importance. Changes in the ice deposition coefficient induce only transient effects on the microphysical properties and radiative impacts of cirrus except in cases of very low ice deposition coefficients of about 0.05. Changes in the sulfate aerosol number concentration available for homogeneous freezing have virtually no effect on the microphysical properties and radiative impact of midlatitude and subtropical cirrus but a minor effect on tropical anvil cirrus. © 2014. American Geophysical Union. All Rights Reserved."
"57034458200;","The effect of parameterized ice microphysics on the simulation of vortex circulation with a mesoscale hydrostatic model",1989,"10.1111/j.1600-0870.1989.tb00371.x","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84981573566&doi=10.1111%2fj.1600-0870.1989.tb00371.x&partnerID=40&md5=9d43da0f2eed6377021ee3da8d8ddc87","It has been proposed that ice microphysics, particularly the melting effect, can play an important rôle in the generation of mesoscale structure and evolution of convective weather systems and associated stratiform rainfall. In this paper, parameterized cloud ice and snow crystals are incorporated into an explicit (grid‐resolved) convective scheme as prognostic variables and tested using an observed mesovortex on a grid resolution of 25 km. With the inclusion of ice microphysics parameterization, the resolvable‐scale precipitation begins to develop nearly 1 h earlier and undergoes a more rapid acceleration. Meanwhile, the resulting maximum upward motion and locally accumulated rainfall are significantly larger than that without ice microphysics. However, the model produced a relatively weak mesovortex circulation with the maximum cyclonic vorticity located more than 50 mb higher when the ice microphysics is incorporated. It is found that the freezing and sublimation provide a positive forcing for the rapid development of the mid‐tropospheric warm‐core vortex circulation, while the melting tends to destroy the concentration of cyclonic vorticity in the lower levels. In particular, intercomparisons among all sensitivity experiments so far performed reveal that the melting effect can be of equal importance to those of the hydrostatic water loading and evaporative cooling in retarding the development of the CISK‐like instability and in reducing the intensity of the mesovortex. The results indicate that the vertical distribution of diabatic heating may be more important than the total heating in determining the strength of mesovortices, when the melting effect is considered. 1989 Blackwell Munksgaard"
"57193528525;16837735900;7005911418;","Evaluation of cumulus and microphysics parameterizations in WRF across the convective gray zone",2019,"10.1175/WAF-D-18-0178.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85072246127&doi=10.1175%2fWAF-D-18-0178.1&partnerID=40&md5=2bece9912b9de469443d5d719fe4de69","This study evaluates the grid-length dependency of the Weather Research and Forecasting (WRF) Model precipitation performance for two cases in the Southern Great Plains of the United States. The aim is to investigate the ability of different cumulus and microphysics parameterization schemes to represent precipitation processes throughout the transition between parameterized and resolved convective scales (e.g., the gray zone). The cases include the following: 1) a mesoscale convective system causing intense local precipitation, and 2) a frontal passage with light but continuous rainfall. The choice of cumulus parameterization appears to be a crucial differentiator in convective development and resulting precipitation patterns in the WRF simulations. Different microphysics schemes produce very similar outcomes, yet some of the more sophis-ticated schemes have substantially longer run times. This suggests that this additional computational expense does not necessarily provide meaningful forecast improvements, and those looking to run such schemes should perform their own evaluation to determine if this expense is warranted for their application. The best performing cumulus scheme overall for the two cases studies here was the scale-aware Grell–Freitas cumulus scheme. It was able to reproduce a smooth transition from subgrid-(cumulus) to resolved-scale (micro-physics) precipitation with increasing resolution. It also produced the smallest errors for the convective event, outperforming the other cumulus schemes in predicting the timing and intensity of the precipitation. © 2019 American Meteorological Society."
"57204050879;7103158465;9239331500;36343109300;","Parameterization of the bulk liquid fraction on mixed-phase particles in the predicted particle properties (P3) Scheme: Description and idealized simulations",2019,"10.1175/JAS-D-18-0278.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85062568567&doi=10.1175%2fJAS-D-18-0278.1&partnerID=40&md5=7e3b6f62fc73919f7d96349076eed178","Bulk microphysics parameterizations that are used to represent clouds and precipitation usually allow only solid and liquid hydrometeors. Predicting the bulk liquid fraction on ice allows an explicit representation ofmixed-phase particles and various precipitation types, such as wet snow and ice pellets. In this paper, an approach for the representation of the bulk liquid fraction into the predicted particle properties (P3) microphysics scheme is proposed and described. Solid-phase microphysical processes, such as melting and sublimation, have been modified to account for the liquid component. New processes, such as refreezing and condensation of the liquid portion of mixed-phase particles, have been added to the parameterization. Idealized simulations using a one-dimensional framework illustrate the overall behavior of the modified scheme. The proposed approach compares well to a Lagrangian benchmark model. Temperatures required for populations of ice crystals to melt completely also agree well with previous studies. The new processes of refreezing and condensation impact both the surface precipitation type and feedback between the temperature and the phase changes. Overall, prediction of the bulk liquid fraction allows an explicit description of new precipitation types, such as wet snow and ice pellets, and improves the representation of hydrometeor properties when the temperature is near 0°C. © 2019 American Meteorological Society."
"55544020300;55522498000;14920052300;55802246600;16312351300;57211306422;41562511500;","Combined impacts of convection and microphysics parameterizations on the simulations of precipitation and cloud properties over Asia",2018,"10.1016/j.atmosres.2018.05.017","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047604032&doi=10.1016%2fj.atmosres.2018.05.017&partnerID=40&md5=db7412724a1122f17881a7b5a22e63c2","Convection and microphysics parameterization schemes (i.e. CPS and MPS) are two important components related to the precipitation and cloud simulations in climate models, and one parameterization's impacts on the results can be dependent on the treatments in the other one. This study investigates the individual and combined impacts of CPS and MPS on the precipitation and cloud simulations over Asia based on nine regional model experiments using combinations of three CPSs of the Kain–Fritsch (KF), Zhang–McFarlane (ZM), and Grell 3D ensemble (G3), and three MPSs of the WRF double-moment 5-class (WDM5), WRF double-moment 6-class (WDM6), and Morrison double-moment (MORR). We first evaluate the simulated precipitation and find the experiment configured with the ZM CPS and MORR MPS performs the best when considering both the precipitation mean magnitude and spatial pattern. The sensitivity analysis results show that enhanced convection due to changing the CPS can cause strengthened or weakened stratiform processes, depending on the height of convective detrainments relative to that of convective drying, which is different among CPSs. In general, the CPS impacts on precipitation and clouds are larger when associating with the MORR MPS than with the other two MPSs as the former simulates more clouds and exhibits larger sensitivity of stratiform-type drying to convective detrainments. The MPS impacts on the precipitation and cloud simulations are also highly related to the CPS's behavior in simulating ice detrainments. Compared to the sum of the individual effects of CPS and MPS, simultaneously changing the two parameterizations causes considerably larger impacts on the precipitation and cloud simulations, suggesting the strong nonlinear interaction between the CPS and MPS. © 2018 Elsevier B.V."
"55793507700;57212816521;7403077486;","Improvements to the snow melting process in a partially double moment microphysics parameterization",2017,"10.1002/2016MS000892","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85019178748&doi=10.1002%2f2016MS000892&partnerID=40&md5=4ba7930addaed76fc3473aad186e3544","Polarimetric upgrades to the U.S. radar network have allowed new insight into the precipitation processes of tropical cyclones. Previous work by the authors compared the reflectivity at horizontal polarization and differential reflectivity observations from two hurricanes to simulated radar observations from the WRF model, and found that the aerosol-aware Thompson-Eidhammer microphysical scheme performed the best of several commonly used bulk microphysical parameterizations. Here we expand our investigation of the Thompson-Eidhammer scheme, and find that though it provided the most accurate forecast in terms of wind speed and simulated radar signatures, the scheme produces areas in which the differential reflectivity was much higher than observed. We conclude that the Thompson-Eidhammer scheme produces drop size distributions that have a larger median drop size than observed in regions of light stratiform precipitation. Examination of the vertical structure of simulated differential reflectivity indicates that the source of the discrepancy between the model and radar observations likely originates within the melting layer. The treatment of number production of rain drops from melting snow in the microphysical scheme is shown to be the ultimate source of the enhancement of differential reflectivity. A modification to the scheme is shown to result in better fidelity of the radar variables with the observations without degrading the short-term intensity forecast. Additional tests with an idealized squall line simulation are consistent with the hurricane results, suggesting the modification is generally applicable. The modifications to the Thompson-Eidhammer scheme shown here have been incorporated into updates of the WRF model starting with version 3.8.1. © 2017. The Authors."
"57210222492;56119272900;56681868600;28568039300;7103101609;7003440089;","Atmospheric moisture supersaturation in the near-surface atmosphere at Dome C, Antarctic Plateau",2017,"10.5194/acp-17-691-2017","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85009348342&doi=10.5194%2facp-17-691-2017&partnerID=40&md5=fe912ad5a71279735b023c108b80b691","Supersaturation often occurs at the top of the troposphere where cirrus clouds form, but is comparatively unusual near the surface where the air is generally warmer and laden with liquid and/or ice condensation nuclei. One exception is the surface of the high Antarctic Plateau. One year of atmospheric moisture measurement at the surface of Dome C on the East Antarctic Plateau is presented. The measurements are obtained using commercial hygrometry sensors modified to allow air sampling without affecting the moisture content, even in the case of supersaturation. Supersaturation is found to be very frequent. Common unadapted hygrometry sensors generally fail to report supersaturation, and most reports of atmospheric moisture on the Antarctic Plateau are thus likely biased low. The measurements are compared with results from two models implementing cold microphysics parameterizations: the European Center for Medium-range Weather Forecasts through its operational analyses, and the Model Atmosphérique Régional. As in the observations, supersaturation is frequent in the models but the statistical distribution differs both between models and observations and between the two models, leaving much room for model improvement. This is unlikely to strongly affect estimations of surface sublimation because supersaturation is more frequent as temperature is lower, and moisture quantities and thus water fluxes are small anyway. Ignoring supersaturation may be a more serious issue when considering water isotopes, a tracer of phase change and temperature, largely used to reconstruct past climates and environments from ice cores. Because observations are easier in the surface atmosphere, longer and more continuous in situ observation series of atmospheric supersaturation can be obtained than higher in the atmosphere to test parameterizations of cold microphysics, such as those used in the formation of high-altitude cirrus clouds in meteorological and climate models. © Author(s) 2017."
"36740698600;55738957800;16246205000;","Effects of convective microphysics parameterization on large-scale cloud hydrological cycle and radiative budget in tropical and midlatitude convective regions",2015,"10.1175/JCLI-D-15-0064.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84950154509&doi=10.1175%2fJCLI-D-15-0064.1&partnerID=40&md5=2efbd5921a974cc430b33e11c0e4131a","A two-moment microphysics scheme for deep convection was previously implemented in the NCAR Community Atmosphere Model version 5 (CAM5) by Song et al. The new scheme improved hydrometeor profiles in deep convective clouds and increased deep convective detrainment, reducing the negative biases in low and midlevel cloud fraction and liquid water path compared to observations. Here, the authors examine in more detail the impacts of this improved microphysical representation on regional-scale water and radiation budgets. As a primary source of cloud water for stratiform clouds is detrainment from deep and shallow convection, the enhanced detrainment leads to larger stratiform cloud fractions, higher cloud water content, and more stratiform precipitation over the ocean, particularly in the subtropics where convective frequency is also increased. This leads to increased net cloud radiative forcing. Over land regions, cloud amounts are reduced as a result of lower relative humidity, leading to weaker cloud forcing and increasedOLR. Comparing the water budgets to cloud-resolving model simulations shows improvement in the partitioning between convective and stratiformprecipitation, though the deep convection is still too active in theGCM. The addition of convective microphysics leads to an overall improvement in the regional cloud water budgets. © 2015 American Meteorological Society."
"56578013900;57194799520;21735071800;","Impact of different microphysical parameterizations on extreme snowfall events in the Southern Andes",2018,"10.1016/j.wace.2018.07.001","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053464184&doi=10.1016%2fj.wace.2018.07.001&partnerID=40&md5=9d79deb8afb1ad9d40a345c38c889cb5","This study evaluates the reliability of the Weather Research and Forecasting (WRF) model to simulate extreme snowfall events in the Southern Andes. The assessment includes comparison of seven microphysics parameterizations (MPs) schemes, using two different reanalysis datasets as boundary and initial conditions, namely NCEP-FNL and ERA-interim. Results demonstrate the feasibility of predicting extreme snow events with reasonable accuracy using WRF, but the accuracy level is dependent on the imposed initial conditions. In particular, by computing the RMSE turned out that the WSM6 under NCEP-FNL performed better as compared with the other schemes in the highly complex topography of the Andes. Conversely, Morrison and WDM5 ranked the worst as both simulated excessive snowfall. For ERA-interim initial conditions, Goddard (WDM6) scheme shows the best (weaker) performance. Despite these limitations, these modeling experiments demonstrate the feasibility of using the WRF to forecast the spatial and temporal distribution of snowfall and precipitation in this region of steep topography. Therefore, modeling experiments may reduce people losses by anticipating the weather threat for local communities, and provide decision makers with information on which to base future interventions for water supply hydrological hazards. © 2018"
"57200691764;53463448400;7006239409;55250905500;15722072200;7403997708;23100590600;","Numerical simulation of a heavy precipitation event in the vicinity of Madrid-Barajas International Airport: Sensitivity to initial conditions, domain resolution, and microphysics parameterizations",2018,"10.3390/atmos9090329","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85052967223&doi=10.3390%2fatmos9090329&partnerID=40&md5=b3b43fa494b1c89093d12cc3fc577dde","Deep convection is a threat to many human activities, with a great impact on aviation safety. On 7 July 2017, a widespread torrential precipitation event (associated with a cut-offlow at mid-levels) was registered in the vicinity of Madrid, causing serious flight disruptions. During this type of episode, accurate short-term forecasts are key to minimizing risks to aviation. The aim of this research is to improve early warning systems by obtaining the best WRF model setup. In this paper, the aforementioned event was simulated. Various model configurations were produced using four different physics parameterizations, 3-km and 1-km domain resolutions, and 0.25° and 1° initial condition resolutions. Simulations were validated using data from 17 rain gauge stations. Two validation indices are proposed, accounting for the temporal behaviour of the model. Results show significant differences between microphysics parameterizations. Validation of domain resolution shows that improvement from 3 to 1 km is negligible. Interestingly, the 0.25° resolution for initial conditions produced poor results compared with 1°. This may be linked to a timing error, because precipitation was simulated further east than observed. The use of ensembles generated by combining different WRF model configurations produced reliable precipitation estimates. © 2018 by the authors."
"56418501800;7003667860;55749601600;","Simulated Kelvin-Helmholtz waves over terrain and their microphysical implications",2018,"10.1175/JAS-D-18-0073.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85050988484&doi=10.1175%2fJAS-D-18-0073.1&partnerID=40&md5=da3fdec58290b7d532b6a74ba70e9c97","Two Kelvin-Helmholtz (KH) wave events over western Washington State were simulated and evaluated using observations from the Olympic Mountains Experiment (OLYMPEX) field campaign. The events, 12 and 17 December 2015, were simulated realistically by the WRF-ARW Model, duplicating the mesoscale environment, location, and structure of embedded KH waves, which had observed wavelengths of approximately 5 km. In simulations of both cases, waves developed from instability within an intense shear layer, caused by low-level easterly flow surmounted by westerly winds aloft. The low-level easterlies resulted from blocking by the Olympic Mountains in the 12 December case, while in the 17 December event, the easterly flow was produced by the synoptic environment. Simulated microphysics were evaluated for both cases using OLYMPEX observations. When the KH waves were within the melting level, simulated microphysical fields, such as hydrometeor mixing ratios, evinced considerable oscillatory behavior. In contrast, when waves were located below the melting level, the microphysical response was attenuated. Turning off the model's microphysics scheme and latent heating resulted in weakened KH wave activity, while removing the Olympic Mountains eliminated KH waves in the 12 December event but not the 17 December case. Finally, the impact of several microphysics parameterizations on KH activity was evaluated for both events. © 2018 American Meteorological Society."
"55621077300;57205299261;","Sensitivities of 1-km forecasts of 24 May 2011 tornadic supercells to microphysics parameterizations",2017,"10.1175/MWR-D-16-0282.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85021261231&doi=10.1175%2fMWR-D-16-0282.1&partnerID=40&md5=b6cb3a7e3360813f0fab5507dbff995b","On 24 May 2011, Oklahoma experienced an outbreak of tornadoes, including one rated EF5 on the enhanced Fujita (EF) scale and two rated EF4. The extensive observation network in this area makes this an ideal case to examine the impact of using five different microphysics parameterization schemes, including single-, double-, and triple-moment microphysics, in an efficient high-resolution data assimilation system suitable for nowcasting and short-term forecasting with low latencies. Additionally, the real-time configuration of the 1-km ARPS, which assimilated increments produced by 3DVAR with cloud analysis using incremental analysis updating (IAU), had success providing a good baseline forecast. ARPS forecasts of 0-2 h are verified using observation-point, neighborhood, and object-based verification techniques. The object-based verification technique uses updraft helicity fields to represent mesocyclone centers, which are verified against tornado locations from three supercells of interest. Varying levels of success in the forecasts are found and appear to be dependent on the complexity of the storm interaction, with early forecasts of isolated storms exhibiting the most success. Verification scores indicate that the multimoment microphysics schemes tend to produce better forecasts of tornadic supercells. However, some of the forecasts from the single-moment microphysics schemes perform as well as or better than the forecasts from the multimoment microphysics schemes. © 2017 American Meteorological Society."
"56034675700;22937961500;22936208200;55431569700;55641116900;","Sensitivity Study of Cloud Cover and Ozone Modeling to Microphysics Parameterization",2017,"10.1007/s00024-015-1227-2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85011976679&doi=10.1007%2fs00024-015-1227-2&partnerID=40&md5=8246f9f7252ea9ed8ef7bbfb6d6b8691","Cloud cover is a significant meteorological parameter influencing the amount of solar radiation reaching the ground surface, and therefore affecting the formation of photochemical pollutants, most of all tropospheric ozone (O3). Because cloud amount and type in meteorological models are resolved by microphysics schemes, adjusting this parameterization is a major factor determining the accuracy of the results. However, verification of cloud cover simulations based on surface data is difficult and yields significant errors. Current meteorological satellite programs provide many high-resolution cloud products, which can be used to verify numerical models. In this study, the Weather Research and Forecasting model (WRF) has been applied for the area of Poland for an episode of June 17th–July 4th, 2008, when high ground-level ozone concentrations were observed. Four simulations were performed, each with a different microphysics parameterization: Purdue Lin, Eta Ferrier, WRF Single-Moment 6-class, and Morrison Double-Moment scheme. The results were then evaluated based on cloud mask satellite images derived from SEVIRI data. Meteorological variables and O3 concentrations were also evaluated. The results show that the simulation using Morrison Double-Moment microphysics provides the most and Purdue Lin the least accurate information on cloud cover and surface meteorological variables for the selected high ozone episode. Those two configurations were used for WRF-Chem runs, which showed significantly higher O3 concentrations and better model-measurements agreement of the latter. © 2016, The Author(s)."
"16242507700;6603504366;55900242900;7003961699;","WRF model sensitivity to choice of parameterization: a study of the ‘York Flood 1999’",2015,"10.1007/s00704-014-1282-0","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84942365722&doi=10.1007%2fs00704-014-1282-0&partnerID=40&md5=530295e77a0d36c8d255bba7dd345bd6","Numerical weather modelling has gained considerable attention in the field of hydrology especially in un-gauged catchments and in conjunction with distributed models. As a consequence, the accuracy with which these models represent precipitation, sub-grid-scale processes and exceptional events has become of considerable concern to the hydrological community. This paper presents sensitivity analyses for the Weather Research Forecast (WRF) model with respect to the choice of physical parameterization schemes (both cumulus parameterisation (CPSs) and microphysics parameterization schemes (MPSs)) used to represent the ‘1999 York Flood’ event, which occurred over North Yorkshire, UK, 1st–14th March 1999. The study assessed four CPSs (Kain–Fritsch (KF2), Betts–Miller–Janjic (BMJ), Grell–Devenyi ensemble (GD) and the old Kain–Fritsch (KF1)) and four MPSs (Kessler, Lin et al., WRF single-moment 3-class (WSM3) and WRF single-moment 5-class (WSM5)] with respect to their influence on modelled rainfall. The study suggests that the BMJ scheme may be a better cumulus parameterization choice for the study region, giving a consistently better performance than other three CPSs, though there are suggestions of underestimation. The WSM3 was identified as the best MPSs and a combined WSM3/BMJ model setup produced realistic estimates of precipitation quantities for this exceptional flood event. This study analysed spatial variability in WRF performance through categorical indices, including POD, FBI, FAR and CSI during York Flood 1999 under various model settings. Moreover, the WRF model was good at predicting high-intensity rare events over the Yorkshire region, suggesting it has potential for operational use. © 2014, Springer-Verlag Wien."
"57192615132;55717074000;7401936984;7401974644;7005877775;","Testing ice microphysics parameterizations in the NCAR Community Atmospheric Model Version 3 using Tropical Warm Pool-International Cloud Experiment data",2009,"10.1029/2008JD011220","https://www.scopus.com/inward/record.uri?eid=2-s2.0-70350064177&doi=10.1029%2f2008JD011220&partnerID=40&md5=b1ba6dff07ee879910d349ea5d2e9163","Cloud properties have been simulated with a new double-moment microphysics scheme under the framework of the single-column version of NCAR Community Atmospheric Model version 3 (CAM3). For comparison, the same simulation was made with the standard single-moment microphysics scheme of CAM3. Results from both simulations compared favorably with observations during the Tropical Warm Pool-International Cloud Experiment by the U.S. Department of Energy Atmospheric Radiation Measurement Program in terms of the temporal variation and vertical distribution of cloud fraction and cloud condensate. Major differences between the two simulations are in the magnitude and distribution of ice water content within the mixed-phase cloud during the monsoon period, though the total frozen water (snow plus ice) contents are similar. The ice mass content in the mixed-phase cloud from the new scheme is larger than that from the standard scheme, and ice water content extends 2 km further downward, which is in better agreement with observations. The dependence of the frozen water mass fraction on temperature from the new scheme is also in better agreement with available observations. Outgoing longwave radiation (OLR) at the top of the atmosphere (TOA) from the simulation with the new scheme is, in general, larger than that with the standard scheme, while the surface downward longwave radiation is similar. Sensitivity tests suggest that different treatments of the ice crystal effective radius contribute significantly to the difference in the calculations of TOA OLR, in addition to cloud water path. Numerical experiments show that cloud properties in the new scheme can respond reasonably to changes in the concentration of aerosols and emphasize the importance of correctly simulating aerosol effects in climate models for aerosol-cloud interactions. Further evaluation, especially for ice cloud properties based on in situ data, is needed."
"55898333500;56122761300;","Assimilation of the radar-derived water vapour mixing ratio into the LM COSMO model with a high horizontal resolution",2009,"10.1016/j.atmosres.2009.01.012","https://www.scopus.com/inward/record.uri?eid=2-s2.0-63149122264&doi=10.1016%2fj.atmosres.2009.01.012&partnerID=40&md5=ae90aed15f2728da076bff5f5d193a22","We use a WVC (Water Vapour Correction) method to assimilate radar reflectivity into the NWP (Numerical Weather Prediction) Local Model COSMO (LM; version 3.18) with a horizontal resolution of 2.8 km. The WVC method takes into account differences between the model and radar-derived precipitation by modifying vertical profiles of the water vapour mixing ratio at each model time step using the nudging approach. We describe the application of the WVC method and apply it to five severe convective events. The LM contains an explicit formulation of cloud and rain processes, in which microphysics parameterization includes rain water, snow, ice, and graupels. We evaluate the WVC method performance and compare it with the latent heat nudging method (LHN), which is a part of the LM code. The evaluation is focused on a very short range forecast of precipitation caused by particular storms. Results show that in most studied cases, both methods can forecast precipitation development three hours ahead, which is approximately the life cycle length of studied storms, and that the assimilation significantly improves precipitation forecasts obtained by the NWP model. Three approaches are used to evaluate and compare the methods. The first evaluates the forecast ""by eye"", the second is based on similarity measure (SRMSE) between precipitation cores, which takes into account area distribution of precipitation, and the third compares values of forecasted maximum precipitation in given areas. The results show that WVC yields better results than LHN in some cases and could be a good alternative to LHN. The relatively good agreement between the verification ""by eye"" and SRMSE confirms that SRMSE can be employed in similar studies. © 2009 Elsevier B.V. All rights reserved."
"55454298000;7005968859;55739897500;","The effects of clouds on aerosol and chemical species production and distribution 1. Cloud model formulation, mixing, and detrainment",1997,"10.1029/97jd01523","https://www.scopus.com/inward/record.uri?eid=2-s2.0-1642554072&doi=10.1029%2f97jd01523&partnerID=40&md5=4660a06c8a975921912c8cf2a3331a46","Clouds play an important role in tropospheric chemical processes and in the modulation of global climate via transport of reactive species from lower levels of the troposphere to higher altitudes and by modification of boundary layer gas and aerosol concentrations by aqueous phase reactions in cloud and precipitation. We present here the initial results of a study of the effects of deep convective clouds upon transport of aerosols and aerosol precursor gases along with a discussion of the formulation of the two-dimensional Eulerian model dynamics and two-moment bulk microphysics parameterization. Results from a test run using data from the Cooperative Convective and Precipitation Experiment show reasonable agreement with observations, although comparison with aircraft observations show the model cannot resolve saturated downdrafts. Comparison with the Taylor and Baker [1991] detrainment criterion shows good agreement for water vapor, a passive tracer, and cloud condensation nuclei."
"24317665500;","Comparison of cloud microphysics parameterizations for simulation of mesoscale clouds and precipitation",1992,"10.1016/0960-1686(92)90004-5","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0027098416&doi=10.1016%2f0960-1686%2892%2990004-5&partnerID=40&md5=4181275b852c66564ba85efda9a191c3","Cloud physics parameterizations are comprehensively reviewed in order to examine their theoretical bases and to evaluate their applicability to mesoscale modeling. The constant distribution functions of hydrometeors assumed in previous work are found to be unrealistic. To circumvent this problem, new parameterizations are developed for mixing ratios of water vapor, cloud water, rain water, cloud ice, graupel and snowflakes. Equations are derived from theoretical considerations and multiple regression applied to results of simulations with a cloud model that incorporates sophisticated treatments of microphysics and dynamics. In a Lagrangian air parcel model under variable atmospheric conditions, the new parameterizations give consistent results and are computationally more efficient than previously available parameterizations. © 1992."
"56448656800;8676866700;35739392600;55214939400;56447397800;57192186616;57192195636;","Evaluation of optimized WRF precipitation forecast over a complex topography region during flood season",2016,"10.3390/atmos7110145","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85000473271&doi=10.3390%2fatmos7110145&partnerID=40&md5=697ab04682f131a47d37d332ad70b177","In recent years, the Weather Research and Forecast (WRF) model has been utilized to generate quantitative precipitation forecasts with higher spatial and temporal resolutions. However, factors including horizontal resolution, domain size, and the physical parameterization scheme have a strong impact on the dynamic downscaling ability of the WRF model. In this study, the influence of these factors has been analyzed in precipitation forecasting for the Xijiang Basin, southern China-a region with complex topography. The results indicate that higher horizontal resolutions always result in higher Critical Success Indexes (CSI), but higher biases as well. Meanwhile, the precipitation forecast skills are also influenced by the combination of microphysics parameterization scheme and cumulus convective parameterization scheme. On the basis of these results, an optimized configuration of the WRF model is built in which the horizontal resolution is 10 km, the microphysics parameterization is the Lin scheme, and the cumulus convective parameterization is the Betts-Miller-Janjic scheme. This configuration is then evaluated by simulating the daily weather during the 2013-2014 flood season. The high Critical Success Index scores and low biases at various thresholds and lead times confirm the high accuracy of the optimized WRF model configuration for Xijiang Basin. However, the performance of the WRF model varies from different sub-basins due to the complexity of the mesoscale convective system (MCS) over this region.. © 2016 by the authors."
"55335005800;55953277900;","Parameterization of the sedimentation of raindrops with finite maximum diameter",2012,"10.1175/MWR-D-11-00020.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84864949573&doi=10.1175%2fMWR-D-11-00020.1&partnerID=40&md5=264dc700caebf13b6a39a945b01277f0","In common cloud microphysics parameterization models, the prognostic variables are one to three moments of the drop size distribution function. They are defined as integrals of the distribution function over a drop diameter ranging from zero to infinity. Recent works (by several authors) on a one-dimensional sedimentation problem have pointed out that there are problems with those parameterization models caused by the differing average propagation speeds of the prognostic moments. In this study, the authors propose to define the moments over a finite drop diameter range of [0, Dmax], corresponding to the limitation of drop size in nature. The ratios of the average propagation speeds are thereby also reduced. In the new model, mean particle masses above a certain threshold depending on Dmax lead to mathematical problems, which are solved by a mirroring technique. An identical, one-dimensional sedimentation problem for two moments is used to analyze the sensitivity of the results to the maximum drop diameter and to compare the proposed method with recent works. It turns out that Dmax has a systematic influence on the model's results.Asmall, finite maximumdrop diameter leads to a better representation of the moments and the mean drop mass when compared to the detailed microphysical model. © 2012 American Meteorological Society."
"16639472200;36614190000;36614005700;56249947100;","PWV forecast validation at ALMA site",2011,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-84878330485&partnerID=40&md5=48ac58f80c69d4ddb6fd6b40be648594","In this study, the WRF (Weather Research and Forecasting) model was implemented to predict the atmospheric conditions, particularly the precipitable water vapor (PWV) in the North of Chile. Its performance was evaluated over the ALMA (Atacama Large Millimeter/submillimeter Array) site. Five WRF configurations with different physical options for boundary layer, soil model and microphysics were compared with observations from a radiometer and a weather station from April to December 2007. The results show that all the simulations overestimate PWV values, particularly in summer months. In addition, the microphysics parameterization changes do not notably affect the forecast, observing improved results with the soil model Noah. The errors were smallest with the YSU-Noah configuration, suggesting that it is appropriate to be used in operational forecasting of PWV in ALMA. © 2011: Instituto de Astronomía, UNAM - Astronomical Site Testing Data in Chile Ed. M. Curé, A. Otárola, J. Marín, & M. Sarazin."
"7005920812;23392868000;","Coupling microphysics parameterizations to cloud parameterizations",2006,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-75149176288&partnerID=40&md5=1c8a143da26f3e7a4b4339ee1e9a79c5",[No abstract available]
"19638530300;7403079681;","Numerical simulation on stratospheric gravity waves above mid-latitude deep convection",2001,"10.1016/S0273-1177(01)00232-0","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0034802990&doi=10.1016%2fS0273-1177%2801%2900232-0&partnerID=40&md5=2fa000ae77f5957fe4d7000e47406556","In this paper, the results of a 3D numerical simulation study of stratospheric gravity wave (GW) excitation above a real storm case which occurred in mid-summer and mid-latitude over China are presented. The model applied is a non-hydrostatic compressible atmospheric model coupled with a bulk cloud-microphysics parameterization. The results demonstrate that the upper tropospheric baroclinic background condition shaped the storm passage and the strong convection developed and was maintained in the upper troposphere. The updrafts penetrated into the tropopause and resulted in significant GWs in the stratosphere. That the tropopause penetration process was closely related to pressure perturbation indicates that the ""obstacle effect"" proposed by Clark et al. (1986) was responsible for the wave excitation. Three distinct sub-areas-the wave-energizing, the wave-exciting and the wave-bearing sub-area, are found to be responsible for the wave generation. The Area-averaged GW momentum flux component, pu'w', was about 0.3 N m -2 at the model's altitude near the tropopause. It is also found that the interaction between convection and background flow caused the asymmetric wave distribution. Further investigation reveals that, due to the energy removal function of the GWs, cross tropopause mass transportation can only occur in the early stage of the tropopause penetration process. The mechanism implied in this relationship between the two processes may be, at least in this study, an explanation for the general finding that the tropopause is a transport barrier. © 2001 COSPAR. Published by Elsevier Science Ltd. All rights reserved."
"56798652100;36606783400;57205061248;7004351010;","Impact of microphysics parameterizations and horizontal resolutions on simulation of “MORA” tropical cyclone over Bay of Bengal using Numerical Weather Prediction Model",2019,"10.1007/s00703-018-0651-0","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85058377233&doi=10.1007%2fs00703-018-0651-0&partnerID=40&md5=f6f6cf54ad840da632e067683a402704","A numerical weather prediction model, Weather Research and Forecasting (WRF model) version 3.8 has been used to simulate a severe cyclonic storm “MORA” observed over Bay of Bengal (BoB) during 28–31 May, 2017. The initial simulation has been carried out over the region at 6-km horizontal resolution with 310 × 330 grid points in both north–south and east–west directions having 30 vertical levels. Initial conditions were used from National Centers for Environmental Prediction (NCEP) Final analysis (FNL) fields available at every 6 h at a spatial resolution of 1° × 1°. The model-simulated features of this event were evaluated against Indian Meteorological Department (IMD) data over the region. Sensitivity experiments were performed using six different microphysics schemes (Lin, Kessler, WSM3, Eta, WSM6 and Thompson) among which WSM3 scheme-simulated track was close to the observed IMD track. The model with WSM3 scheme has efficiently captured many important features in simulating the occurrence of the storm accompanied with wind speed, and sea level pressure, though there are some spatial and temporal biases in the simulation. After choosing the best microphysics scheme, we looked into the model performance in simulating the storm at different horizontal resolutions, 4 km and 9 km with 480 × 510 and 210 × 210 grid points, respectively. The results clearly revealed that cyclone track as well as other parameters related to the storm are sensible to horizontal resolution and has improved after finer resolution (i.e., 4 km) simulation. © 2018, Springer-Verlag GmbH Austria, ein Teil von Springer Nature."
"16432757400;7004156981;","Numerical experiments with RAMS model in highly complex terrain",2018,"10.1007/s10652-017-9553-9","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85032839121&doi=10.1007%2fs10652-017-9553-9&partnerID=40&md5=769be5af17f3b0bf8bdc18984d0458ab","RAMS mesoscale model has been applied to simulate the atmospheric circulation in highly complex terrain, in the Hindu-Kush Karakorum and Himalaya regions. The goal of the work is to assess the sensitivity of the model to the grid spacing and related resolution, the smoothing of the orography, the microphysics parameterizations, in such heterogeneous and challenging conditions. As a follow up, the capability of the model in correctly capturing the atmospheric processes is tested. Two main cases, where some measured data were available, have been considered: a period during which a flood occurred and a period characterised by high-pollution episodes. RAMS model provided sensible results, the predictions reasonably reproduce the observed data at a regional scale, but the most local characteristics cannot be definitely described even at the typical resolution of 1 km order. © 2017, Springer Science+Business Media B.V."
"57206438122;7405460591;","The hydrometeor partitioning and microphysical processes over the Pacific Warm Pool in numerical modeling",2017,"10.1016/j.atmosres.2016.09.009","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84988909694&doi=10.1016%2fj.atmosres.2016.09.009&partnerID=40&md5=2f253a2e8c80086291b3d393cfb5dbe2","Numerical modeling is conducted to study the hydrometeor partitioning and microphysical source and sink processes during a quasi-steady state of thunderstorms over the Pacific Warm Pool by utilizing the microphysical model WISCDYMM to simulate selected storm cases. The results show that liquid-phase hydrometeors dominate thunderstorm evolution over the Pacific Warm Pool. The ratio of ice-phase mass to liquid-phase mass is about 41%: 59%, indicating that ice-phase water is not as significant over the Pacific Warm Pool as the liquid water compared to the larger than 50% in the subtropics and ~ 80% in the US High Plains in a previous study. Sensitivity tests support the dominance of liquid-phase hydrometeors over the Pacific Warm Pool. The major rain sources are the key hail sinks: melting of hail and shedding from hail; whereas the crucial rain sinks are evaporation and accretion by hail. The major snow sources are Bergeron-Findeisen process, transfer of cloud ice to snow and accretion of cloud water; whereas the foremost sink of snow is accretion by hail. The essential hail sources are accretions of rain, cloud water, and snow; whereas the critical hail sinks are melting of hail and shedding from hail. The contribution and ranking of sources and sinks of these precipitates are compared with the previous study. Hydrometeors have their own special microphysical processes in the development and depletion over the Pacific Warm Pool. Microphysical budgets depend on atmospheric dynamical and thermodynamical conditions which determine the partitioning of hydrometeors. This knowledge would benefit the microphysics parameterization in cloud models and cumulus parameterization in global circulation models. © 2016 Elsevier B.V."
"55914640400;26535270500;55783436900;7202048112;56993785500;","Uncertainty and feasibility of dynamical downscaling for modeling tropical cyclones for storm surge simulation",2016,"10.1007/s11069-016-2482-y","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84983283271&doi=10.1007%2fs11069-016-2482-y&partnerID=40&md5=4d3fcf64c788e0935f7e24e1b9553b34","This paper presents a modeling study conducted to evaluate the uncertainty of a regional model in simulating hurricane wind and pressure fields, and the feasibility of driving coastal storm surge simulation using an ensemble of region model outputs produced by 18 combinations of 3 convection schemes and 6 microphysics parameterizations, using Hurricane Katrina as a test case. Simulated wind and pressure fields were compared to observed H*Wind data for Hurricane Katrina, and simulated storm surge was compared to observed high-water marks on the northern coast of the Gulf of Mexico. The ensemble modeling analysis demonstrated that the regional model was able to reproduce the characteristics of Hurricane Katrina with reasonable accuracy and can be used to drive the coastal ocean model for simulating coastal storm surge. Results indicated that the regional model is sensitive to both convection and microphysics parameterizations that simulate moist processes closely linked to the tropical cyclone dynamics that influence hurricane development and intensification. The Zhang and McFarlane (ZM) convection scheme and the Lim and Hong (WDM6) microphysics parameterization are the most skillful in simulating Hurricane Katrina maximum wind speed and central pressure, among the three convection and the six microphysics parameterizations. Error statistics of simulated maximum water levels were calculated for a baseline simulation with H*Wind forcing and the 18 ensemble simulations driven by the regional model outputs. The storm surge model produced the overall best results in simulating the maximum water levels using wind and pressure fields generated with the ZM convection scheme and the WDM6 microphysics parameterization. © 2016, Springer Science+Business Media Dordrecht."
"57164038200;37053536700;","Impact of microphysics schemes in the simulation of cyclone hudhud using WRF-ARW model",2016,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-84960420419&partnerID=40&md5=f82a8f2b23f214b5f754bcdba36872f0","A Very Severe Cyclonic Strom (VSCS) ""Hudhud"" crossed Andhra coast near Visakhapatnam on 12th October 2014 and caused significant damage to property due to both wind and surge. In the present study, an attempt is made to simulate and test the capability of the state of art Advanced Research Weather Research and Forecasting (WRF-ARW) model in capturing the wind intensity and track of cyclone accurately. The simulation has been carried out using three domains with a horizontal resolution of 27 km for domain 1, 9 km for domain 2 and 3 km for domain 3. Multiple simulations using initial conditions (NCEP FNL) at an interval of 6 hours, same cumulus parameterization and time integration schemes but with different microphysics schemes are carried out. The main source of energy for tropical cyclone is the latent hear release (convective heating) in clouds, which depend on microphysical processes and the released dynamical properties. The objective of the present study is to find out the best microphysics for accurate simulation of intensity and track of tropical cyclone at high model domain resolution towards storm surge studies. The best performance was found for the model integrated for 48 hours starting from 10th October 2014 to 12th October 2014. Simulated features include (track, maximum sustained wind, sea level pressure and rainfall) were compared with IMD best track data and it was observed that simulations with WRF LIN microphysics scheme compare well with observations. Other synoptic features of rainfall was also simulated and discussed in relation to model performance. Overall this study gives emphasis on the studies towards sensitivity analysis of microphysics parameterization using WRF simulations at high model grid resolution (3 km) to imply towards storm surge applications in Bay of Bengal. © Research India Publications."
"7409565134;","Evaluation of cloud microphysics parameterizations for mesoscale simulations",1989,"10.1016/0169-8095(89)90046-X","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0024874126&doi=10.1016%2f0169-8095%2889%2990046-X&partnerID=40&md5=dedd88e81907754d019f42c0ab70eb86","The theoretical bases for parameterizations of cloud microphysics are examined, and their applicability for mesoscale modeling is evaluated. We find that the constant distribution functions of hydrometeors assumed in previous work are unrealistic. To circumvent this problem, we have made new parameterizations by multiple regression on mixing ratios of water vapor, cloud water, and rainwater, using solution fields derived from simulations of a cloud model that incorporates sophisticated treatments of microphysics and dynamics. In the detailed simulations from which they were derived, the regression parameterizations generally give better results than do the existing parameterizations tested. When compared with previously available parameterizations a Lagrangian air parcel model under variable atmospheric conditions, the new paramerizations give consistent results and are computationally more efficient. © 1989."
"56531986900;6507979420;57192174561;9839112600;15050523700;57200641300;56414554900;55832456200;9942293700;35253736000;6604005739;6603265463;6602369858;14021454400;7004202450;","WRF model sensitivity to choice of PBL and microphysics parameterization for an advection fog event at Barkachha, rural site in the Indo-Gangetic basin, India",2019,"10.1007/s00704-018-2530-5","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048886391&doi=10.1007%2fs00704-018-2530-5&partnerID=40&md5=89fe305be7b11b20fe98e4f8a2e56e51","The present study evaluates the performance of four planetary boundary layer (PBL) parameterization schemes combined with five cloud microphysics schemes in Weather Research Forecasting (WRF) model, specifically for an advection fog event occurred during 4–6 December 2014 at Barkachha, rural site in the Indo-Gangetic plain (IGP). For this purpose, the model was configured over the IGP with 2-km horizontal resolution, and results are compared with detailed micrometeorological data (surface meteorological parameters and fluxes, radiative fluxes, and surface layer wind profiles) gathered during the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) Integrated Ground Observational Campaign (IGOC) site located in the IGP. The meteorological conditions conducive for the fog formation have been evaluated. All of the tested PBL-microphysics combination showed substantial bias for surface temperature, radiation fluxes, and wind speed. None of the combination found to be superior in predicting the fog event; however, the local MYNN2.5 combination with the WSM3, WSM6, and Lin microphysics obtained slightly better result at the study location. In general, judging from all simulations of liquid water content (as an indicator for the fog), the above combinations were able to simulate the current fog event but the fog onset, duration, and dissipation were particularly offset. © 2018, Springer-Verlag GmbH Austria, part of Springer Nature."
"12794067600;57218150135;37052082800;","Effect of hydrometeor species on very-short-range simulations of precipitation using ERA5",2019,"10.1016/j.atmosres.2018.12.008","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85058379922&doi=10.1016%2fj.atmosres.2018.12.008&partnerID=40&md5=b89c28783d73ac9d2cb720c1b6871822","The impact of five hydrometeor species provided by the fifth generation of ECMWF ReAnalysis (ERA5) on the skill of precipitation forecasts is investigated in very-short-range numerical weather prediction modeling using WRF. Three sets of experiments using different numbers of hydrometeors as input in the initial and lateral boundary conditions were designed for 6-h forecasts run over the region of Korea in East Asia during two one-month periods of the summer and winter seasons: specific humidity only, additional specific cloud liquid water and cloud ice water, and additional specific rain water and snow water. The 6-class Thompson microphysics parameterization scheme that uses prognostic condensate variables was adopted for forecasts to represent the effect of using these hydrometeors in the initial conditions. Simulated precipitation was verified against surface observations in terms of both categorical scores based on contingency tables and object-oriented measures. The evaluation of the precipitation skill reveals that the forecasts using multiple hydrometeors as input generally show increased skill of precipitation forecasts compared to forecasts using only specific humidity as input. It is found that the increase of precipitation forecasting skill appears both in winter and in summer. Using more hydrometeors in the initial conditions reduces the spin-up time and accelerates the occurrence of resolved precipitation in the model. This effect is clearly shown in the first one to two hours of the forecast. Afterwards, the precipitation forecast skill is similar to that of forecasts that use only specific humidity as input in the initial conditions. The more hydrometeor species used in the initial conditions of the forecast model, the more skillful becomes its precipitation forecast in the initial hours. Another set of experiments using liquid- and ice-phase hydrometeors separately shows that initialization with ice-phase hydrometers would be slightly more important to improving precipitation forecasts. Note that the results reported here should be understood as valid under the specific experimental configuration in this paper. © 2018 Elsevier B.V."
"55405340400;8658386900;7005920812;6701754792;7406215388;","Dependence of Vertical Alignment of Cloud and Precipitation Properties on Their Effective Fall Speeds",2019,"10.1029/2018JD029346","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85061896893&doi=10.1029%2f2018JD029346&partnerID=40&md5=3f883b649d478323e646bfe18b21d8f8","The vertical structure of clouds unresolved in large-scale weather prediction and climate models is controlled by an overlap assumption. When a binary representation (cloud or no cloud) of subgrid horizontal variability is replaced by a probability density function (PDF) treatment of cloud-related variables, a cloud occurrence overlap needs to be replaced by a PDF overlap. The PDF overlap can be quantified by a correlation length scale, z 0 , indicating how rapidly rank correlation of distributions at two levels diminishes with increasing level separation. In this study, we show that z 0 varies widely for different properties (e.g., number and mass mixing ratios) and different hydrometeor types (cloud liquid and ice, rain, snow, and graupel) and that corresponding fall speed, V f , is the primary factor controlling the degree of their vertical alignment, with vertical shear of the horizontal wind playing a smaller role. Linear and power law parametric relationships between z 0 and V f are derived using cloud-resolving simulations of convection under midlatitude continental and tropical oceanic conditions, as well as observations from vertically pointing dual-frequency radar profilers near Darwin, Australia. The functional form of z 0 -V f relationship is further examined using simple conceptual models that link variability in horizontal and vertical directions and provide insights into the role of V f and wind shear. Being based on a physical property (i.e., fall speed) of hydrometeors rather than artificially defined and model-specific hydrometeor types, the proposed parameterization of vertical PDF overlap can be applied to a wide range of microphysics treatments in regional and global models. ©2019. The Authors."
"7006018705;57204548566;57204544718;6701557528;","A cloud microphysics parameterization for shallow cumulus clouds based on Lagrangian cloud model simulations",2018,"10.1175/JAS-D-18-0080.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85056111089&doi=10.1175%2fJAS-D-18-0080.1&partnerID=40&md5=60c27b01fdf4f968e941a2ee99768ba2","Cloud microphysics parameterizations for shallow cumulus clouds are analyzed based on Lagrangian cloud model (LCM) data, focusing on autoconversion and accretion. The autoconversion and accretion rates,A and C, respectively, are calculated directly by capturing the moment of the conversion of individual Lagrangian droplets from cloud droplets to raindrops, and it results in the reproduction of the formulas of A and C for the first time. Comparison with various parameterizations reveals the closest agreement with Tripoli and Cotton, such as A=αNc -1/3 qc 7/3 H(R2RT) and C=βqcqr, where qc and Nc are the mixing ratio and the number concentration of cloud droplets, qr is the mixing ratio of raindrops, RT is the threshold volume radius, and His the Heaviside function. Furthermore, it is found that a increases linearly with the dissipation rate « and the standard deviation of radius s and that RT decreases rapidly with σ while disappearing at σ &gt; 3.5 μm. The LCMalso reveals that σ and ε increase with time during the period of autoconversion, which helps to suppress the early precipitation by reducing A with smaller a and larger RT in the initial stage. Finally, β is found to be affected by the accumulated collisional growth, which determines the drop size distribution. © 2018 American Meteorological Society."
"56660169800;55344551600;7005342702;","ISOLESC: A Coupled Isotope-LSM-LES-Cloud Modeling System to Investigate the Water Budget in the Atmospheric Boundary Layer",2018,"10.1029/2018MS001381","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85055727277&doi=10.1029%2f2018MS001381&partnerID=40&md5=f7573d96b3e43f44fea457f3f46c955a","Stable isotopes of water (H2O, HDO, and H2 18O) are tracers that provide powerful constraints on water transport processes in the atmosphere. This paper presents a description of an atmospheric boundary layer (ABL) simulation system called ISOLESC that couples water isotope fractionation processes with a land surface model, a large eddy simulation model, and a two-moment cloud microphysics parameterization. Results from two model configurations—one with shallow precipitating cumulus and the other for a cloud-free ABL—are presented to evaluate the model performance and determine its sensitivity to isotopic parameterizations. The coupled model successfully reproduces important ABL statistics (ABL height, cloud fraction, and cloud liquid water content), the expected effects of mixing and fractionation on the time evolution of ABL vapor isotopic composition, and observed diurnal variations of near-surface water vapor isotopic composition. For the current configuration, nondiscriminating entrainment contributes 17% to the subdaily time variation of near-surface vapor deuterium excess, while surface evapotranspiration contributes 83%. The isotopic compositions of water vapor and cloud water are insensitive to mesh resolution, but the profiles of cloud water specific humidity, rainwater specific humidity, and its isotopic ratios show moderate response to changes in grid size. Since ISOLESC resolves the energy containing scales of turbulent motions in the ABL and incorporates microphysical processes, it can be used for constraining ABL parameterizations. We find that a further improvement of raindrop reevaporation in the current cloud microphysical scheme is required in order to produce realistic near-surface raindrop deuterium excess for the case simulated here. We suggest that ISOLESC provides a quantitative framework for utilizing vapor-phase isotopic measurements to study local hydrological processes. ©2018. The Authors."
"38061131200;7102080550;","Prediction of the 14 June 2010 Oklahoma City extreme precipitation and flooding event in a multiphysics multi-initial-conditions storm-scale ensemble forecasting system",2016,"10.1175/WAF-D-15-0116.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84984621879&doi=10.1175%2fWAF-D-15-0116.1&partnerID=40&md5=bc5bc6113924dc42771b7d4dbc1b9a62","Prolonged heavy rainfall produced widespread flooding in the Oklahoma City area early on 14 June 2010. This event was poorly predicted by operational models; however, it was skillfully predicted by the Storm-Scale Ensemble Forecast produced by the Center for Analysis and Prediction of Storms as part of the Hazardous Weather Testbed 2010 Spring Experiment. In this study, the quantitative precipitation forecast skill of ensemble members is assessed and ranked using a neighborhood-based threat score calculated against the stage IV precipitation data, and Oklahoma Mesonet observations are used to evaluate the forecast skill for surface conditions. Statistical correlations between skill metrics and qualitative comparisons of relevant features for higher- and lower-ranked members are used to identify important processes. The results demonstrate that the development of a cold pool from previous convection and the movement and orientation of the associated outflow boundary played dominant roles in the event. Without assimilated radar data from this earlier convection, the modeled cold pool was too weak and too slow to develop. Furthermore, forecast skill was sensitive to the choice of microphysics parameterization; members that used the Thompson scheme produced initial cold pools that propagated too slowly, substantially increasing errors in the timing and placement of later precipitation. The results also suggest important roles played by finescale, transient features in the period of outflow boundary stalling and reorientation associated with the heaviest rainfall. The unlikelihood of a deterministic forecast reliably predicting these features highlights the benefit of using convection-allowing/convection-resolving ensemble forecast methods for events of this kind. © 2016 American Meteorological Society."
"57203247832;6603662103;56257109300;","A modelling case study of a large-scale cirrus in the tropical tropopause layer",2016,"10.5194/acp-16-3881-2016","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84961935891&doi=10.5194%2facp-16-3881-2016&partnerID=40&md5=da784f7849204cda6bbd79474ad8546d","We use the Weather Research and Forecast (WRF) model to simulate a large-scale tropical tropopause layer (TTL) cirrus in order to understand the formation and life cycle of the cloud. This cirrus event has been previously described through satellite observations by Taylor et al. (2011). Comparisons of the simulated and observed cirrus show a fair agreement and validate the reference simulation regarding cloud extension, location and life time. The validated simulation is used to understand the causes of cloud formation. It is shown that several cirrus clouds successively form in the region due to adiabatic cooling and large-scale uplift rather than from convective anvils. The structure of the uplift is tied to the equatorial response (equatorial wave excitation) to a potential vorticity intrusion from the midlatitudes. Sensitivity tests are then performed to assess the relative importance of the choice of the microphysics parameterization and of the initial and boundary conditions. The initial dynamical conditions (wind and temperature) essentially control the horizontal location and area of the cloud. However, the choice of the microphysics scheme influences the ice water content and the cloud vertical position. Last, the fair agreement with the observations allows to estimate the cloud impact in the TTL in the simulations. The cirrus clouds have a small but not negligible impact on the radiative budget of the local TTL. However, for this particular case, the cloud radiative heating does not significantly influence the simulated dynamics. This result is due to (1) the lifetime of air parcels in the cloud system, which is too short to significantly influence the dynamics, and (2) the fact that induced vertical motions would be comparable to or smaller than the typical mesoscale motions present. Finally, the simulation also provides an estimate of the vertical redistribution of water by the cloud and the results emphasize the importance in our case of both rehydration and dehydration in the vicinity of the cirrus."
"24317665500;35318561700;","Comparison of microphysics parameterizations in a three-dimensional dynamic cloud model",1994,"10.1016/1352-2310(94)90307-7","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0028431019&doi=10.1016%2f1352-2310%2894%2990307-7&partnerID=40&md5=b839dbc0a157fb0cfd0a03464023380c","A three-dimensional, time-dependent flow model developed to simulate dynamics and cloud microphysics for warm-cloud processes is used to compare the moisture fields simulated with different cloud microphysics parameterization. Our parameterizations are based on detailed simulations of the physics of aerosols, clouds, and precipitation. The moisture content in the system is differentiated into water vapor, cloud water, and rain water. Advection and diffusion terms for momentum, potential temperature, and mixing ratios of water vapaor and cloud water are calculated by using finite-volume methods, while rain water mixing ratio fields are calculated by a Lagrangian method. The model simulations are examined through sensitivity analysis, interpreted in terms of the physical processes occurring, and are compared with simulations using parameterizations from the literature. Calculated precipitation totals are shown to vary by 10-30% among simulations with alternate parameterization. © 1994."
"55813857400;55803438700;57202891206;6603968694;7006539346;","Diagnosing added value of convection-permitting regional models using precipitation event identification and tracking",2020,"10.1007/s00382-018-4294-0","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85049672137&doi=10.1007%2fs00382-018-4294-0&partnerID=40&md5=efe1b7244e11e5322c15fa7e6b25705b","Dynamical downscaling with high-resolution regional climate models may offer the possibility of realistically reproducing precipitation and weather events in climate simulations. As resolutions fall to order kilometers, the use of explicit rather than parametrized convection may offer even greater fidelity. However, these increased resolutions both allow and require increasingly complex diagnostics for evaluating model fidelity. In this study we focus on precipitation evaluation and analyze five 2-month-long dynamically downscaled model runs over the continental United States that employ different convective and microphysics parameterizations, including one high-resolution convection-permitting simulation. All model runs use the Weather Research and Forecasting Model driven by National Center for Environmental Prediction reanalysis data. We show that employing a novel rainstorm identification and tracking algorithm that allocates essentially all rainfall to individual precipitation events (Chang et al. in J Clim 29(23):8355–8376, 2016) allows new insights into model biases. Results include that, at least in these runs, model wet bias is driven by excessive areal extent of individual precipitating events, and that the effect is time-dependent, producing excessive diurnal cycle amplitude. This amplified cycle is driven not by new production of events but by excessive daytime enlargement of long-lived precipitation events. We further show that in the domain average, precipitation biases appear best represented as additive offsets. Of all model configurations evaluated, convection-permitting simulations most consistently reduced biases in precipitation event characteristics. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature."
"57195327788;7103158465;42062523800;8982105800;57189999417;7004242319;9239331500;","Sensitivity of Simulated Deep Convection to a Stochastic Ice Microphysics Framework",2019,"10.1029/2019MS001730","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85074797460&doi=10.1029%2f2019MS001730&partnerID=40&md5=83b15dafcff96a8c4749d0c3b70830c1","Ice microphysics parameterizations in models must make major simplifications relative to observations, typically employing empirical relationships to represent average functional properties of particles. However, previous studies have established that ice particle properties vary even in similar cloud types and thermodynamic environments, and it remains unclear how this so-called “natural variability” impacts simulated deep convection. This uncertainty is addressed by implementing a stochastic framework into the Predicted Particle Properties microphysics scheme in the Weather Research and Forecasting model. The approach stochastically varies the coefficients of the mass-size (m-D) relationship (m=aDb) for unrimed and partially rimed ice. Using guidance from aircraft in situ measurements obtained during the Midlatitude Continental Convective Clouds Experiment (MC3E), the scheme samples from distributions of the prefactor (a) and the exponent (b) of the m-D relationship. Simulations of two MC3E deep convective cases indicate that the stochastic m-D scheme produces considerable variability of anvil cirrus cloud optical depth (τ) distributions, even for the same ice water path (IWP). Thus, the stochastic scheme produces variable cloud radiative forcing that is independent of IWP. This τ-IWP relationship variability is nonexistent using the deterministic m-D ensemble. Additional sensitivity tests are performed in which the fallspeed-size relationship (V=cDd) is stochastically varied, resulting in variable precipitation amounts and rain rate distributions. Results are presented in the context of satellite and precipitation observations and include comparison with other ensemble configurations using perturbed initial and lateral boundary conditions and small-amplitude noise added to the potential temperature field. ©2019. The Authors."
"57201684500;55861417200;55480762900;57190019472;35114397100;","Sensitivity analysis of raindrop size distribution parameterizations in WRF rainfall simulation",2019,"10.1016/j.atmosres.2019.05.019","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85065908321&doi=10.1016%2fj.atmosres.2019.05.019&partnerID=40&md5=551992fb451f484b0fd3cc16c7850d9a","Numerical weather models such as weather research and forecasting (WRF) are increasingly used in studies on water resources. However, they have suffered from relatively poor performance in rainfall estimation. Among the various influential factors, a critical parameter in the WRF model rainfall retrieval is raindrop size distribution (DSD), which has not been fully explored. The analysis of sensitivity and uncertainty of the DSD model accuracy is significant for rainfall forecasts based on mesoscale numerical weather prediction (NWP) models. A WRF-disdrometer integrated error assessment framework is developed to analyze the accuracy and sensitivity of DSD parameterizations of gamma distribution in WRF rainfall simulation. This study adopts three different microphysics parameterizations (Morrison, WDM6, and Thompson aerosol-aware) to simulate the DSD of approximately 100 rainfall events in Chilbolton, UK that are categorized into 12 scenarios based on the season, rainfall evenness, and rainfall rate. The Thompson aerosol-aware microphysics scheme shows the best performance among the three. In comparisons of WRF rainfall simulations across different scenarios of evenness and rainfall rate, a higher accuracy is obtained with more even rain and a higher rainfall rate. The sensitivity results of different DSD parameterizations indicate that the sensitivity to the intercept parameter N0 is pronouncedly higher than those to the shape parameter μ and slope parameter λ for all studied schemes. The overall WRF rainfall shows a trend of slight underestimation followed by overestimation as μ increases; further, the rainfall is overestimated when log10N0 or λ decreases and is underestimated when it increases and then remains constant. Comparisons of different scenarios reveal that variations of DSD parameters of even rain have a relatively high impact on rainfall recognizability, and the DSD parameterizations show a higher sensitivity for rainfall with a low rate. Moreover, the sensitivity discrimination is not clear among the rainfall of different seasons. The uncertainty assessment of the WRF rainfall retrieval caused by the shape parameter suggests that a gamma DSD model with a variable shape parameter should be developed according to the evenness, rainfall rate, and microphysics parameterizations by using the WRF model. Some modified algorithms of the WRF gamma DSD model for achieving better accuracy in WRF rainfall retrievals will be explored in future studies with various climatic regimes by adjusting the DSD parameterization based on the assimilation of measured data. © 2019"
"7201398636;7005868133;7005872245;","Microphysical process comparison of three microphysics parameterization schemes in the WRF model for an idealized squall-line case study",2019,"10.1175/MWR-D-18-0249.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85075811560&doi=10.1175%2fMWR-D-18-0249.1&partnerID=40&md5=a4609cd854f1ed4606569ddd2504ca4d","Three bulk microphysics schemes with different complexities in the Weather Research and ForecastingModel are compared in terms of the individual microphysical process terms of the hydrometeor mass andnumber mixing ratio tendency equations in an idealized 2D squall-line case. Through evaluation of theseprocess terms and of hydrometeor size distributions, it is shown that the differences in the simulated population characteristics of snow, graupel, and rainwater are the prominent factors contributing to the differences in the development of the simulated squall lines using these schemes. In this particular case, the gustfront propagation speed produced by the Thompson scheme is faster than in the other two schemes during thefirst 2 h of the simulation because it has a larger dominant graupel size. After 2 h into the simulation, theinitially less intense squall lines in the runs using the WSM6 and Morrison schemes start to catch up inintensity and development to the run using the Thompson scheme. Because the dominant size of graupelparticles in the runs using the WSM6 and Morrison schemes is smaller, these particles take more time to fallbelow the freezing level and enhance the rainwater production and its evaporative cooling. In the run usingthe Thompson scheme, the graupel production slows down at later times while the snow particle growthincreases, leading to more snow falling below the freezing level to melt and surpass graupel particle melting inthe production of rainwater. © 2019 American Meteorological Society."
"57193810896;7201920155;","Analysis and prediction of a mesoscale convective system over East China with an ensemble square root filter radar data assimilation approach",2018,"10.1002/asl.806","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042476298&doi=10.1002%2fasl.806&partnerID=40&md5=09c9a186f3957a182858b4f0aff233f2","A mesoscale convective system (MCS) over East China on June 5, 2009 was thoroughly analyzed using an Advanced Regional Prediction System (ARPS) ensemble square root filter (EnSRF) system. The analyzed reflectivity structure, location and intensity compared well with observation, and were substantially better than an experiment without radar data assimilation. The cold pool and wind speed in the convective regions were strengthened. With improved initial conditions, the impact of single-moment (SM), double-moment (DM) and triple-moment (TM) microphysics parameterization (MP) schemes on ensemble forecasts of MCSs was evaluated. The use of multi-moment (MM) MP schemes showed some improvements in neighborhood ensemble probability for reflectivity and precipitation. Quantitative reflectivity and precipitation forecast skills were also improved in MM forecasts, with those of the TM forecast the best. © 2018 The Authors. Atmospheric Science Letters published by John Wiley & Sons Ltd on behalf of the Royal Meteorological Society."
"56514158200;6701529849;56513793000;57219710812;7005247232;","Forecast of precipitation in the area of Bogashevo airport using the WRF model",2014,"10.1134/S1024856014020080","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84950237350&doi=10.1134%2fS1024856014020080&partnerID=40&md5=d85f25a9d901a67ed62d0e49a03b7d04","Numerical simulation results obtained for meteorological conditions in the area of Bogashevo airport and the city of Tomsk using the Weather Research & Forecasting (WRF) mesoscale system are presented. The main attention is paid to choosing the parameterization of microphysical processes adequate for conditions of Western Siberia with the aim to obtain a reliable forecast of intense rainfalls. The performed comparison of predicted and factual data on precipitation and cloudiness demonstrated good possibilities of the model for forecasting precipitation and dangerous events for aviation. The ETA microphysics parameterization yielded the best results. © 2014, Pleiades Publishing, Ltd."
"55335005800;55953277900;","A comparative study of B-, Γ- and log-normal distributions in a three-moment parameterization for drop sedimentation",2014,"10.3390/atmos5030484","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84906074340&doi=10.3390%2fatmos5030484&partnerID=40&md5=388b288da31341b89806b2b1808bc835","This paper examines different distribution functions used in a three-moment parameterization scheme with regard to their influence on the implementation and the results of the parameterization scheme. In parameterizations with moment methods, the prognostic variables are interpreted as statistical moments of a drop size distribution, for which a functional form has to be assumed. In cloud microphysics, parameterizations are frequently based on gamma- and log-normal distributions, while for particle-laden flows in engineering, the beta-distribution is sometimes used. In this study, the three-moment schemes with beta-, gamma- and log-normal distributions are tested in a 1D framework for drop sedimentation, and their results are compared with those of a spectral reference model. The gamma-distribution performs best. The results of the parameterization with the beta- and the log-normal distribution have less similarity to the reference solution, particularly with regard to number density and rain rate. Theoretical considerations reveal that (depending on the type of the distribution function) only selected combinations of moments can be predicted together. Among these is the important combination of ""number density, liquid water content, radar reflectivity"" for all three distributions. Advection or source/sink terms can only be calculated under certain conditions on the moment values (positivity of the Hankel-Hadamard determinant). These are derived from mathematical theory (""moment problem"") and are more restrictive for three-moment than for two-moment schemes. © 2014 by the authors."
"7406523040;6506585275;","The cloud processes of a simulated moderate snowfall event in North China",2006,"10.1007/s00376-006-0235-7","https://www.scopus.com/inward/record.uri?eid=2-s2.0-33646560326&doi=10.1007%2fs00376-006-0235-7&partnerID=40&md5=d9b986861ed98f5de82a1e8685fbcbd2","The understanding of the cloud processes of snowfall is essential to the artificial enhancement of snow and the numerical simulation of snowfall. The mesoscale model MM5 is used to simulate a moderate snowfall event in North China that occurred during 20-21 December 2002. Thirteen experiments are performed to test the sensitivity of the simulation to the cloud physics with different cumulus parameterization schemes and different options for the Goddard cloud microphysics parameterization schemes. It is shown that the cumulus parameterization scheme has little to do with the simulation result. The results also show that there are only four classes of water substances, namely the cloud water, cloud ice, snow, and vapor, in the simulation of the moderate snowfall event. The analysis of the cloud microphysics budgets in the explicit experiment shows that the condensation of supersaturated vapor, the depositional growth of cloud ice, the initiation of cloud ice, the accretion of cloud ice by snow, the accretion of cloud water by snow, the deposition growth of snow, and the Bergeron process of cloud ice are the dominant cloud microphysical processes in the simulation. The accretion of cloud water by snow and the deposition growth of the snow are equally important in the development of the snow."
"7103158465;55544490500;6506545080;57193882808;7202784114;24398842400;35572096100;22980035400;9239331500;6701596624;6701718281;16242392800;57216240246;7101928629;22635999400;14018610000;","Confronting the Challenge of Modeling Cloud and Precipitation Microphysics",2020,"10.1029/2019MS001689","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089951757&doi=10.1029%2f2019MS001689&partnerID=40&md5=05e6f0c169f0d263b76dda85ab112ab2","In the atmosphere, microphysics refers to the microscale processes that affect cloud and precipitation particles and is a key linkage among the various components of Earth's atmospheric water and energy cycles. The representation of microphysical processes in models continues to pose a major challenge leading to uncertainty in numerical weather forecasts and climate simulations. In this paper, the problem of treating microphysics in models is divided into two parts: (i) how to represent the population of cloud and precipitation particles, given the impossibility of simulating all particles individually within a cloud, and (ii) uncertainties in the microphysical process rates owing to fundamental gaps in knowledge of cloud physics. The recently developed Lagrangian particle-based method is advocated as a way to address several conceptual and practical challenges of representing particle populations using traditional bulk and bin microphysics parameterization schemes. For addressing critical gaps in cloud physics knowledge, sustained investment for observational advances from laboratory experiments, new probe development, and next-generation instruments in space is needed. Greater emphasis on laboratory work, which has apparently declined over the past several decades relative to other areas of cloud physics research, is argued to be an essential ingredient for improving process-level understanding. More systematic use of natural cloud and precipitation observations to constrain microphysics schemes is also advocated. Because it is generally difficult to quantify individual microphysical process rates from these observations directly, this presents an inverse problem that can be viewed from the standpoint of Bayesian statistics. Following this idea, a probabilistic framework is proposed that combines elements from statistical and physical modeling. Besides providing rigorous constraint of schemes, there is an added benefit of quantifying uncertainty systematically. Finally, a broader hierarchical approach is proposed to accelerate improvements in microphysics schemes, leveraging the advances described in this paper related to process modeling (using Lagrangian particle-based schemes), laboratory experimentation, cloud and precipitation observations, and statistical methods. ©2020. The Authors."
"57210582290;7402966606;55727880700;57198776938;56463154100;","Sensitivity of Summer Precipitation Simulation to Microphysics Parameterization Over Eastern China: Convection-Permitting Regional Climate Simulation",2019,"10.1029/2019JD030295","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85070948242&doi=10.1029%2f2019JD030295&partnerID=40&md5=e9d30066d95bbe35dfb1c31dbc3cb9ec","With a six-year (2009–2014) summer climate simulation using the Weather Research and Forecasting model at convection-permitting resolution (4-km grid spacing), the effects of microphysics parameterization (MP) schemes on precipitation characteristics are investigated in this study. The convection-permitting simulations employ three popular MP schemes, namely, Lin (single-moment bulk MP), Weather Research and Forecasting Single-Moment 5-class (one-moment and mixed-phased MP), and Thompson (two-moment and mixed-phase MP) scheme. By evaluating the simulations against the CMORPH, rain gauge (Station), and ERA-Interim data, it is found that the convection-permitting model reproduce well the summer precipitation amount and the associated large-scale atmospheric circulations, which are insensitive to the choice of MP schemes. The simulations with three MP schemes overestimate the precipitation amount, especially over the Yangtze-Huaihe River Valley. The overestimations may be due to the systematic biases, and cannot be significantly reduced by using different MP schemes. Moreover, all simulations capture well the major features of precipitation diurnal variations and their transition characteristics, but they significantly overestimate the precipitation frequency while underestimate the precipitation intensity. The analysis on the microphysical hydrometeors shows that the model-simulated precipitation amount is considerably affected by the vertical profiles of solid hydrometeors, especially the snow and graupel particles. The Thompson scheme creates more snow particles and less graupel than the other schemes, while produces the least precipitation amount that best matches the CMORPH. ©2019. American Geophysical Union. All Rights Reserved."
"55533258800;9239331500;","The importance of the ice-phase microphysics parameterization for simulating the effects of changes to CCN concentrations in deep convection",2019,"10.1175/JAS-D-18-0168.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85067200279&doi=10.1175%2fJAS-D-18-0168.1&partnerID=40&md5=735efe11b5f26090a73a5bb3c270e11a","Simulations of a well-observed squall line that occurred during the Midlatitude Continental Convective Clouds Experiment (MC3E) were conducted using a mesoscale model with a horizontal grid spacing of 1 km to examine the importance of parameterized ice-phase processes to changes in concentrations of activated cloud condensation nuclei (CCN) in a detailed two-moment bulk microphysics scheme. Numerical experiments showed that the simulated squall-line structure was sensitive to changes in activated CCN concentration not only from the direct impacts on cloud droplet sizes and autoconversion rates, but also because of changes in the growth rates and spatial distribution of ice-phase condensate. A microphysical budget analysis highlighted the importance of graupel in rain production and the sensitivity of graupel growth rates on changes to CCN concentrations. Sensitivity tests on the level of detail in the representation of graupel, specifically the treatment of its bulk density and the number of prognostic moments, indicated that changes in the reflectivity and precipitation structure of the simulated storm due to changes in CCN were sensitive to the graupel parameterization. The results suggest that the proper representation of graupel and possibly other ice-phase categories in microphysics schemes may be crucial for correctly simulating the effects of changes to CCN concentrations for continental deep convective systems. © 2019 American Meteorological Society."
"57190374357;18133904700;8968458700;7403213622;","Calibration of a multi-physics ensemble for estimating the uncertainty of a greenhouse gas atmospheric transport model",2019,"10.5194/acp-19-5695-2019","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85065077472&doi=10.5194%2facp-19-5695-2019&partnerID=40&md5=e4bbaa10996ea6874102365045122da5","Atmospheric inversions have been used to assess biosphere-atmosphere CO2 surface exchanges at various scales, but variability among inverse flux estimates remains significant, especially at continental scales. Atmospheric transport errors are one of the main contributors to this variability. To characterize transport errors and their spatiotemporal structures, we present an objective method to generate a calibrated ensemble adjusted with meteorological measurements collected across a region, here the upper US Midwest in midsummer. Using multiple model configurations of theWeather Research and Forecasting (WRF) model, we show that a reduced number of simulations (less than 10 members) reproduces the transport error characteristics of a 45-member ensemble while minimizing the size of the ensemble. The large ensemble of 45 members was constructed using different physics parameterization (i.e., land surface models (LSMs), planetary boundary layer (PBL) schemes, cumulus parameterizations and microphysics parameterizations) and meteorological initial/boundary conditions. All the different models were coupled to CO2 fluxes and lateral boundary conditions from CarbonTracker to simulate CO2 mole fractions. Observed meteorological variables critical to inverse flux estimates, PBL wind speed, PBL wind direction and PBL height are used to calibrate our ensemble over the region. Two optimization techniques (i.e., simulated annealing and a genetic algorithm) are used for the selection of the optimal ensemble using the flatness of the rank histograms as the main criterion. We also choose model configurations that minimize the systematic errors (i.e., monthly biases) in the ensemble. We evaluate the impact of transport errors on atmospheric CO2 mole fraction to represent up to 40% of the model-data mismatch (fraction of the total variance).We conclude that a carefully chosen subset of the physics ensemble can represent the uncertainties in the full ensemble, and that transport ensembles calibrated with relevant meteorological variables provide a promising path forward for improving the treatment of transport uncertainties in atmospheric inverse flux estimates. © Author(s) 2019."
"57194654728;6701782029;57189949072;7103114146;7004458729;","Evaluation of physical parameterizations for atmospheric river induced precipitation and application to long-term reconstruction based on three reanalysis datasets in Western Oregon",2019,"10.1016/j.scitotenv.2018.12.214","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85058953649&doi=10.1016%2fj.scitotenv.2018.12.214&partnerID=40&md5=7e64dfd9401cff4be35f92c91569d6e7","Dynamically downscaled precipitation is often used for evaluating sub-daily precipitation behavior on a watershed-scale and for the input to hydrological modeling because of its increasing accuracy and spatiotemporal resolution. Despite these advantages, physical parameterizations in regional models and systematic biases due to the dataset used for boundary conditions greatly influence the quality of downscaled precipitation data. The present paper aims to evaluate the performance and the sensitivities of physical parameterizations of the Weather Research and Forecasting (WRF) model to simulate extreme precipitation associated with atmospheric rivers (ARs) over the Willamette watershed in Oregon. Also investigated was whether the optimized WRF configuration for extreme events can be used for long-term reconstruction using different boundary condition datasets. Three reanalysis datasets, the Twentieth Century Reanalysis version 2c (20CRv2c), the European Center for Medium-Range Weather Forecasts (ECMWF) twentieth century reanalysis (ERA20C), and the Climate Forecast System Reanalysis (CFSR), which have different spatial resolutions and dataset periods, were used to simulate precipitation at 4 km resolution. Sensitivity analyses showed that AR precipitation is most sensitive to the microphysics parameterization. Among 13 microphysics schemes investigated, the Goddard and the Stony-Brook University schemes performed the best regardless of the choice of reanalysis. Reconstructed historical precipitation with the optimized configuration showed better accuracies during the wet season than the dry season. With respect to simulations with CFSR, it was found that the optimized configuration for AR precipitation can be used for long-term reconstruction with small biases. However, systematic biases in the reanalysis datasets may still lead to uncertainties in downscaling precipitation in a different season with a single configuration. © 2018 Elsevier B.V."
"57207990344;7003276018;","Numerical investigations of atmospheric rivers and the rain shadow over the Santa Clara Valley",2019,"10.3390/atmos10030114","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063547523&doi=10.3390%2fatmos10030114&partnerID=40&md5=585046b895e50ef7dce1a0ee908f2523","This study investigated precipitation distribution patterns in association with atmospheric rivers (ARs). The Weather Research and Forecasting (WRF) model was employed to simulate two strong atmospheric river events. The precipitation forecasts were highly sensitive to cloud microphysics parameterization schemes. Thus, radar observed and simulated ZH and ZDR were evaluated to provide information about the drop-size distribution (DSD). Four microphysics schemes (WSM-5, WSM-6, Thompson, and WDM-6) with nested simulations (3 km, 1 km, and 1/3 km) were conducted. One of the events mostly contained bright-band (BB) rainfall and lasted less than 24 h, while the other contained both BB and non-bright-band (NBB) rainfall, and lasted about 27 h. For each event, there was no clear improvement in the 1/3 km model, over the 1 km model. Overall, the WDM-6 microphysics scheme best represented the rainfall and the DSD. It appears that this scheme performed well, due to its relative simplicity in ice and mixed-phase microphysics, while providing double-moment predictions of warm rain microphysics (i.e.; cloud and rain mixing ratio and number concentration). The other schemes tested either provided single-moment predictions of all classes or double-moment predictions of ice and rain (Thompson). Considering the shallow nature of precipitation in atmospheric rivers and the high-frequency of the orographic effect enhancing the warm rain process, these assumptions appear to be applicable over the southern San Francisco Bay Area. © 2019 by the authors."
"57208282014;55624399200;54983414800;","The relative impact of ice fall speeds and microphysics parameterization complexity on supercell evolution",2019,"10.1175/MWR-D-18-0417.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85074888804&doi=10.1175%2fMWR-D-18-0417.1&partnerID=40&md5=c7f61410f1dc21096f658072c60ab638","The use of bin or bulk microphysics schemes in model simulations frequently produces large changes in the simulated storm and precipitation characteristics, but it is still unclear which aspects of these schemes give rise to these changes. In this study, supercell simulations using either a bin or a double-moment bulk microphysics scheme are conducted with the Regional Atmospheric Modeling System (RAMS). The two simulations produce very different storm morphologies. An additional simulation is run for each scheme in which the diameter-fall speed relationships for ice hydrometeors are modified to be similar to those used by the other scheme. When fall speed relationships are homogenized, the two parameterization schemes simulate similar storm morphology. Therefore, despite the use of largely dissimilar approaches to parameterizing microphysics, the difference in storm morphology is found to be related to the choice of diameter-fall speed relationships for ice hydrometeors. This result is investigated further to understand why. Higher fall speeds lead to higher mixing ratios of hydrometeors at low levels and thus more melting. Consequently, stronger downdrafts and cold pools exist in the high fall speed storms, and these stronger cold pools lead to storm splitting and the intensification of a left mover. The results point to the importance of hydrometeor fall speed on the evolution of supercells. It is also suggested that caution be used when comparing the response of a cloud model to different classes of microphysics schemes since the assumptions made by the schemes may be more important than the scheme class itself. © 2019 American Meteorological Society."
"56464971600;7004479957;36876405100;7102696626;","Evolution of the Double-ITCZ Bias Through CESM2 Development",2019,"10.1029/2019MS001647","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85068537131&doi=10.1029%2f2019MS001647&partnerID=40&md5=79ca64ae0f222f7b7e5f9195eec1d239","The structure of the east Pacific Intertropical Convergence Zone (ITCZ) as simulated in the Community Earth System Model version 2 (CESM2) is greatly improved as compared to its previous version, CESM version 1. Examination of intermediate model versions created as part of the development process for CESM2 shows the improvement in the ITCZ is well correlated with a reduction in the relative warmth of southeast Pacific sea surface temperatures (SSTs) as compared to the broader tropical mean. Cooling SST in this region enhances the zonal SST and surface pressure gradients and reduces the anomalously southward SST gradient present in boreal spring in early version of CESM2. The improvements in southeast Pacific SST are attributed to increases in low cloud cover and the associated shortwave cloud forcing over the southeast. Sensitivity tests using fixed SST simulations demonstrate the increase in cloud cover between two intermediate model versions, 119 and 125, to be driven by removal of the dependence of autoconversion and accretion rates on cloud water variance as well as the removal of a secondary condensation scheme. Both of these changes reduce drizzle rates in warm clouds increasing cloud lifetime and cloud fraction in the stratocumulus to trade cumulus transition region. The improvements in southeast Pacific shortwave cloud forcing and ITCZ climatology persist through subsequent changes to the cloud microphysics parameterizations. Despite improvements in the east Pacific ITCZ, the global mean ITCZ position and Pacific cold tongue bias strength do not exhibit a systematic improvement across the development simulations. ©2019. The Authors."
"55258538700;57194424401;7201920155;57203099969;","The impact of stochastically perturbed parameterizations on tornadic supercell cases in East China",2019,"10.1175/MWR-D-18-0182.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85060203187&doi=10.1175%2fMWR-D-18-0182.1&partnerID=40&md5=49d1c03d29334f981693fbb9d6cde6cd","The impact of stochastically perturbed parameterizations on short-term tornadic supercell ensemble forecasts (EFs) was evaluated using two tornado cases that occurred in eastern China. The initial condition (IC) perturbations of EFs were generated by a three-dimensional variational data assimilation system with perturbed radar data. The parameterization perturbations of EFs were produced by a stochastic procedure that was applied to diffusion and microphysics parameterizations. This procedure perturbed tendencies from both parameterizations and intercept parameters (INTCPs) of the microphysics parameterizations. In addition to individually perturbing these quantities, a combination of perturbations of diffusion and INTCPs was also examined. A resampling method was proposed to handle perturbations that vary substantially, and a vertical localization was applied to the microphysics tendency perturbations. The results indicated that combining perturbations of diffusion and INTCPs produced the intensity and path forecasts of the low-level vortex (LLV) that better match observations for a weak tornado case; this combination also had a positive impact on the LLV intensity forecast for a much stronger tornado case. This combination outperformed the stochastic procedures that perturbed only diffusion or INTCPs, which indicated that it is better to use both error representations. The vertical localization prevented the temperature tendency perturbations of microphysics from always suppressing storms in negative perturbation ( < 0.0) areas. The negative INTCP and diffusion perturbations benefited the strong LLV, which is consistent with that of the idealized case. The current stochastic procedure could not address the LLV displacement error that is caused by the IC error. © 2018 American Meteorological Society."
"54790275800;57205302128;55496163500;56041901600;7006581229;8703963700;","Impact of Soil Moisture Uncertainty on Summertime Short-range Ensemble Forecasts",2018,"10.1007/s00376-017-7107-1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048075133&doi=10.1007%2fs00376-017-7107-1&partnerID=40&md5=6a0ff446c46ab1c090e9362e982df041","To investigate the impact of soil moisture uncertainty on summertime short-range ensemble forecasts (SREFs), a fivemember SREF experiment with perturbed initial soil moisture (ISM) was performed over a northern China domain in summertime from July to August 2014. Five soil moisture analyses from three different operational/research centers were used as the ISM for the ensemble. The ISM perturbation produced notable ensemble spread in near-surface variables and atmospheric variables below 800 hPa, and produced skillful ensemble-mean 24-h accumulated precipitation (APCP24) forecasts that outperformed any single ensemble member. Compared with a second SREF experiment with mixed microphysics parameterization options, the ISM-perturbed ensemble produced comparable ensemble spread in APCP24 forecasts, and had better Brier scores and resolution in probabilistic APCP24 forecasts for 10-mm, 25-mm and 50-mm thresholds. The ISM-perturbed ensemble produced obviously larger ensemble spread in near-surface variables. It was, however, still under-dispersed, indicating that perturbing ISM alone may not be adequate in representing all the uncertainty at the near-surface level, indicating further SREF studies are needed to better represent the uncertainties in land surface processes and their coupling with the atmosphere. © 2018, Chinese National Committee for International Association of Meteorology and Atmospheric Sciences, Institute of Atmospheric Physics, Science Press and Springer-Verlag GmbH Germany, part of Springer Nature."
"56032511300;7409080503;57200205038;55388912500;55719002200;55522563200;12040335900;26537846300;17347195800;57200206237;56397588800;","Effects of model resolution and parameterizations on the simulations of clouds, precipitation, and their interactions with aerosols",2018,"10.5194/acp-18-13-2018","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85040198121&doi=10.5194%2facp-18-13-2018&partnerID=40&md5=f5d9e72b4de684430ecbda1bdcfb32c0","This study investigates the roles played by model resolution and microphysics parameterizations in the well-known uncertainties or errors in simulations of clouds, precipitation, and their interactions with aerosols by the numerical weather prediction (NWP) models. For this investigation, we used cloud-system-resolving model (CSRM) simulations as benchmark simulations that adopt high-resolution and full-fledged microphysical processes. These simulations were evaluated against observations, and this evaluation demonstrated that the CSRM simulations can function as benchmark simulations. Comparisons between the CSRM simulations and the simulations at the coarse resolutions that are generally adopted by current NWP models indicate that the use of coarse resolutions as in the NWP models can lower not only updrafts and other cloud variables (e.g., cloud mass, condensation, deposition, and evaporation) but also their sensitivity to increasing aerosol concentration. The parameterization of the saturation process plays an important role in the sensitivity of cloud variables to aerosol concentrations. while the parameterization of the sedimentation process has a substantial impact on how cloud variables are distributed vertically. The variation in cloud variables with resolution is much greater than what happens with varying microphysics parameterizations, which suggests that the uncertainties in the NWP simulations are associated with resolution much more than microphysics parameterizations. © Author(s) 2018."
"55914539400;7006460542;7202208382;7006173068;","Advances towards the development of a cloud-resolving model in South Africa",2014,"10.1590/sajs.2014/20130133","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84988603091&doi=10.1590%2fsajs.2014%2f20130133&partnerID=40&md5=7eb9262194aacc3e6bea4c93bd6878ce","Recent advances in supercomputing have made feasible the numerical integration of high-resolution cloud-resolving models (CRMs). CRMs are being used increasingly for high-resolution operational numerical weather prediction and for research purposes. We report on the development of a new CRM in South Africa. Two bulk microphysics parameterisation schemes were introduced to a dynamical core of a two-dimensional Non-hydrostatic σ-coordinate Model (NSM) developed in South Africa. The resulting CRM was used to simulate two 12-day periods and an 8-day period observed during the Tropical Oceans Global Atmosphere Coupled Ocean-Atmosphere Response Experiment. The response of the NSM to the large-scale forcing which occurred over the three periods, and which included both suppressed and active convection, was examined. The NSM is shown to be able to capture the differences in the three experiments and responds correctly to the large-scale forcing (i.e. it is able to distinguish between suppressed and active regimes). However, the model simulations are cooler and drier than the observations. We demonstrate progress made in the development of a CRM in South Africa, which can be used to study the attributes of convective rainfall over the region. © 2014. The Authors."
"7006952638;","Precipitation calculation method based on parameterization of distribution function evolution and its performance in global spectral atmospheric model",2004,"10.1016/j.jhydrol.2003.11.012","https://www.scopus.com/inward/record.uri?eid=2-s2.0-6444224790&doi=10.1016%2fj.jhydrol.2003.11.012&partnerID=40&md5=26d63dcbba59f601b17ea5c37398b83e","A new method of precipitation calculation, based on cloud microphysics parameterization is presented. The main idea of the method is to parameterize the evolution of distribution function during precipitation formation process. Gravitational and turbulent coalescence of cloud particles are assumed to be the main processes leading to the rain formation. The method considers the precipitation formation in liquid and mixed phase clouds. The phase state of a cloudy layer is calculated as a function of temperature. The effects of precipitation forcing in underlying cloudy layers, melting and evaporation are taken into account. The proposed method was introduced to a large-scale condensation scheme of the global spectral atmospheric model of the Hydrometcentre of Russia. Numerical experiments with the new version of model were conducted. The numerical results were verified using precipitation observations. The experiments show that the new method improves the skill of precipitation forecast for lead times 24-72 h in summer and 24-36 h in spring. © 2003 Elsevier B.V. All rights reserved."
"7004472363;55937180800;7003836546;55880561900;","Modelling study of the IOP2 cold front of the FRONTS 87 experiment",1998,"10.1017/S1350482798001066","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0039016534&doi=10.1017%2fS1350482798001066&partnerID=40&md5=16f166b77ee17e12bee4aa6e899cecd3","On 11-12 November 1987, a frontal system associated with an intense narrow cold frontal rainband was observed over the Channel between England and France. This case constitutes intensive observational period 2 (IOP2) of the FRONTS 87 experiment. It was an ideal example of upper-level and low-level jet coupling with substantial ascending motions and precipitation. The frontal system is analysed, in this paper, using the mesoscale non-hydrostatic model CSU/RAMS. The model uses a two-way interactive nested grid structure and full cloud microphysics parameterisation at various levels of complexity. The model results are compared with previous numerical investigations of this case as well as with observations obtained from the experimental network deployed during the campaign. The model succeeded in representing the frontal structure at meso- and convective scales, taking into account the large scale forcing; thus it is an important tool for the study of secondary cyclogenesis observed during the FASTEX campaign."
"57218603695;6506144245;55628589750;6603954179;","Identifying the key challenges for fog and low stratus forecasting in complex terrain",2020,"10.1002/qj.3849","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089752989&doi=10.1002%2fqj.3849&partnerID=40&md5=381200621f4dff72f23ed8366817cc03","Forecasting fog and low stratus (FLS) accurately poses a challenge to current numerical weather prediction models, despite many advancements in recent years. We present a novel method to quantify FLS extent bias by comparing forecasts with satellite observations. Evaluating a four-month period, we show that COSMO-1, the MeteoSwiss high-resolution operational model, exhibits a considerable negative FLS bias during wintertime. To study the cause, we conduct a series of sensitivity experiments for a representative case study, where COSMO-1 dissipated extensive FLS erroneously. Replacing the one-moment bulk microphysics parameterisation scheme by a two-moment scheme, as well as increasing the number of vertical levels, did not show any improvements. The FLS dissipation was delayed (but not prevented) by decreasing the lower bound imposed on the turbulent diffusion coefficients from 0.4 to 0.01 m2·s−1, or by reducing horizontal grid spacing from 1.1 km to 550 m. Additionally, simulations at 1.1-km grid spacing with smoothed orography led to more extensive FLS than the same simulations without smoothed orography. An analysis of the cloud water budget revealed that the model's advection scheme is causing a loss of liquid water content near the cloud top. A simulation with an alternative terrain-following coordinate system, in which the vertical coordinates are quasihorizontal near the cloud top, reduced the loss of cloud water through advection and improved the evolution of FLS in the case study. In combination, our findings suggest that the advection scheme exhibits numerical diffusion, which promotes spurious mixing in the vertical of cloudy and adjacent cloud-free grid cells in terrain-following vertical coordinates; this process can become the root cause for too rapid dissipation of FLS during nighttime in complex terrain. © 2020 Royal Meteorological Society"
"56593857400;56487672200;14018610000;57207146124;57196134240;57205718149;","Comparison of three microphysics parameterization schemes in the WRF model for an extreme rainfall event in the coastal metropolitan City of Guangzhou, China",2020,"10.1016/j.atmosres.2020.104939","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85081018247&doi=10.1016%2fj.atmosres.2020.104939&partnerID=40&md5=d75529e15431f977b4909f985a1b2616","An extreme rainfall event in the coastal metropolitan city of Guangzhou, China is simulated by the Weather Research and Forecasting (WRF) model using three bulk microphysics schemes to explore the capability to reproduce the observed precipitation features by these schemes and their differences. The detailed comparison among the three runs in terms of radar reflectivity, precipitation, thermodynamic fields and microphysical processes are conducted. Results show that all the simulations can reproduce the two main heavy rainfall centers in Guangzhou and the first convection initiation. The accumulated precipitation in the simulation using the WSM6 scheme performs better than the others in terms of intensity and distribution compared to observations. The weaker accumulated precipitation in the second heavy rainfall center in the simulations using the Thompson and Morrison schemes result from their more dispersed precipitation distributions dominated by the cold pool intensity and distribution. The latent heating from the water vapor condensation dominates the convection initiation and storm development. The latent cooling from the rain water evaporation dominates the cold pool intensity and distribution, which influences the storm moving and subsequent convection propagation, and finally the intensity and distribution of surface precipitation. Sensitivity experiments of the latent heat confirm the dominant roles of latent heating/cooling, especially the water vapor condensation heating and rain water evaporation cooling, in the differences of the thermodynamic fields, storm development, convection propagation and surface precipitation among the three simulations. © 2020 Elsevier B.V."
"57216978750;7003708056;35867442600;7003880283;","The sensitivity of intense rainfall to aerosol particle loading - A comparison of bin-resolved microphysics modelling with observations of heavy precipitation from HyMeX IOP7a",2020,"10.5194/nhess-20-1469-2020","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85085604794&doi=10.5194%2fnhess-20-1469-2020&partnerID=40&md5=645c620634f83ff4261cc46200c9c8fa","Over the Cévennes-Vivarais region in southern France 5&thinsp;h intensive rainfall covering an area of 1000&thinsp;km<span classCombining double low line""inline-formula"">2</span> with more than 50&thinsp;mm of rain accumulation was observed during IOP7a of HyMeX. This study evaluates the performance of a bin-resolved cloud model for simulating this heavy-precipitation event. The simulation results were compared with observations of rain accumulation, radar reflectivity, temporal and spatial evolution of precipitation, 5&thinsp;min rain rates, and raindrop size distributions (RSDs). The different scenarios for aerosol number concentrations range from 1000 to 2900&thinsp;cm<span classCombining double low line""inline-formula"">-3</span> and represent realistic conditions for this region. Model results reproduce the heavy-precipitation event with respect to maximum rain intensity, surface area covered by intense rain and the duration, as well as the RSD. Differences occur in the short-term rainfall rates, as well as in the drop number concentration. The cloud condensation number concentration has a notable influence on the simulated rainfall, on both the surface amount and intensity but also on the RSD properties, and should be taken into account in microphysics parameterizations. © 2020 Copernicus GmbH. All rights reserved."
"57193882808;","Separating physical impacts from natural variability using piggybacking (master-slave) technique",2019,"10.5194/adgeo-49-105-2019","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85072124000&doi=10.5194%2fadgeo-49-105-2019&partnerID=40&md5=43d01cf4131bfb2242193ab79fcb3636","In a chaotic system, like moist convection, it is difficult to separate the impact of a physical process from effects of natural variability. This is because modifying even a small element of the system physics typically leads to a different system evolution and it is difficult to tell whether the difference comes from the physical impact or it merely represents a different flow realization. This paper discusses a relatively simple and computationally efficient modelling methodology that allows separation of the two. The methodology is referred to as the piggybacking or the master-slave approach. The idea is to use two sets of thermodynamic variables (the temperature, water vapor, and all aerosol, cloud, and precipitation variables) in a single cloud simulation. The two sets differ in a specific element of the physics, such as aerosol properties, microphysics parameterization, large-scale forcing, environmental profiles, etc. One thermodynamic set is coupled to the dynamics and drives the simulated flow, and the other set piggybacks the flow, that is, thermodynamic variables are carried by the flow but they do not affect it. By switching the two sets (i.e. the set driving the simulation becomes the piggybacking one, and vice versa), the impact on the cloud dynamics can be evaluated. This paper provides details of the method and reviews results of its application to such problems as the postulated deep convection invigoration in polluted environments, the impact of changes in environmental profiles (e.g., due to climate change) on convective dynamics, and the role of cloud-layer heterogeneities for shallow convective cloud field evolution. Prospects for applying piggybacking technique to other areas of atmospheric simulation (e.g., weather prediction or geoengineering) are also mentioned. © Author(s) 2019. This work is distributed under the Creative Commons Attribution 4.0 License."
"57202925605;35209683700;56923937200;55615078100;7201920350;7401796996;","A synoptic assessment of the summer extreme rainfall over the middle reaches of Yangtze River in CMIP5 models",2019,"10.1007/s00382-019-04803-3","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85065714534&doi=10.1007%2fs00382-019-04803-3&partnerID=40&md5=9a6574f4bfa42d1148460687dcb6c578","The summer mean and extreme rainfall over the middle reaches of Yangtze River (MRYR) are underestimated in many models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). Our earlier work has identified three synoptic-scale circulation patterns associated with extreme rainfall events over the MRYR during early summer. It is verified here that the presence of these patterns indeed increases the likelihood of the occurrence of extreme rainfall over the MRYR. This relationship between the synoptic-scale circulation pattern and extreme rainfall is reproduced by only a subset of CMIP5 models, where the underestimated frequency of the corresponding synoptic-scale circulation patterns partly explains the underestimated frequency of extreme rainfall thus the summer total over the MRYR. Our analysis also reveals that a few models could “accidentally” simulate a realistic rainfall total and probability distribution of daily rain rate over the MRYR region during summer by generating their own model-dependent synoptic-scale circulation patterns that are not typically seen in observations. These findings suggest that a projection of future changes in extreme rainfall over the MRYR will be better constrained dynamically if we use a subset of models that can reproduce the “rainfall-circulation” relationship, given the diverse response of different circulation patterns to radiative forcing changes in the atmosphere. The results presented here also demonstrate the importance of tracking biases of synoptic-scale circulations in understanding model deficiencies in precipitation simulation, in addition to investigating problems in model physics such as cumulus schemes and microphysics parameterization. Nevertheless, these results are based on the analyses of extreme rainfall in one region and one season, further research covering other regions/seasons is needed. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature."
"55805614000;","The effects of ice microphysics on the inner core thermal structure of the hurricane boundary layer",2019,"10.1007/s00703-018-0616-3","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048549363&doi=10.1007%2fs00703-018-0616-3&partnerID=40&md5=a6ea08ba08b52c5d0a215bd99d3d5bab","The effects of five cloud microphysics parameterizations on the mean thermal structure of the tropical cyclone boundary layer (TCBL) are examined by numerical experiments with an axisymmetric, non-hydrostatic model. It is shown that although the radial and azimuthal velocity remains “slaved” to the gradient flow above the TCBL, the strength of the boundary layer updrafts (and downdrafts) and the location of the cloud base (which is connected to the location of the stable layer within the TCBL) depend sensitively on the microphysics parameterization. From an analysis of the potential temperature and water vapor mixing ratio budgets, it is found that latent heat release within the eyewall above the cloud base is balanced by the strong cooling tendency due to vertical advection above the cloud base. Below the cloud base, it is found that the downward flux of high θ is largely balanced by rain evaporation. Near the surface, it is shown that warm rain microphysical parameterizations enhance near-surface evaporation rates compared to their ice microphysics counterparts (which affect the thermal structure of the surface layer). Finally, it is shown that diagnostic TCBL models generally underestimate rainwater evaporation rates compared to the full non-hydrostatic model. © 2018, Springer-Verlag GmbH Austria, part of Springer Nature."
"57192432884;7103158465;7404521962;6506385754;25031430500;","On the covariability of cloud and rain water as a function of length scale",2019,"10.1175/JAS-D-19-0048.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85075573813&doi=10.1175%2fJAS-D-19-0048.1&partnerID=40&md5=ec437db5235072e9244d7f24f19bd6a5","Microphysics parameterizations in large-scale models often account for subgrid variability in the calculation of process rates by integrating over assumed subgrid distributions of the input variables. The variances and covariances that define distribution width may be specified or diagnosed. The correlation r of cloud and rain mass mixing ratio/liquid water content (LWC) is a key input for accurate prediction of the accretion rate and a constant value is typically assumed. In this study, high-frequency aircraft measurements with a spatial resolution of ≈22 cm are used to evaluate the scaling behavior of cloud and rain LWC (qc and qr, respectively) and to demonstrate how and why covariability varies with length scale ℓ. It is shown that power spectral densities of both qc and qr exhibit scale invariance across a wide range of scales (2.04–142 m for qc; 33–1.45 3 104 m for qr). Because the cloud–rain cospectrum is also scale invariant ρ is therefore expected to vary with ℓ. Direct calculation of ρ shows that it generally increases with ℓ, but there is significant variability in the ρ–ℓ relationship that primarily depends on cloud drop number concentration N and cloud cellular organization, suggesting that ρ may also vary with cloud regime. A parameterization of ρ as a function of ℓ and N is developed from aircraft observations and implications for diagnosis of ρ from limited-area model output are also discussed. © 2019 American Meteorological Society."
"26643615000;35494005000;7410041005;9249239700;8723504500;","Partitioning ice water content from retrievals and its application in model comparison",2018,"10.1175/JAS-D-17-0017.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047067680&doi=10.1175%2fJAS-D-17-0017.1&partnerID=40&md5=22cbe9fd87a19d7a02e716a4d7323844","Retrieved bulk microphysics from remote sensing observations is a composite of ice, snow, and graupel in the three-species ice-phase bulk microphysics parameterization. In this study, density thresholds are used to partition the retrieved ice particle size distribution (PSD) into small, median, and large particle size modes from millimeter cloud radar (MMCR) observations in the tropics and global CloudSat and CALIPSO ice cloud property product (2C-ICE) observations. It shows that the small mode can contribute to more than 60% of the total ice water content (IWC) above 12 km (colder than 220 K). Below that, dominant small mode transitions to dominant median mode. The large mode contributes to less than 10%-20% at all height levels. The PSD assumption in retrieval may cause about 10% error in the IWC partition ratio. The lidar-only region in 2C-ICE is dominated by the small mode, while the median mode dominates the radar-only region. For the three-species ice-phase bulk microphysics parameterizations, the cloud ice mass mainly consists of the small mode. But snow and graupel in the models are not equivalent to the median and large modes in the observations, respectively. Therefore, they need to be repartitioned with rebuilt PSDs from the model assumptions using the same partition technique as the observations. The repartitioned IWCs in each mode from different ice species need to be added together and then compared with the corresponding mode from observations. © 2018 American Meteorological Society."
"6602576357;6602404019;","The effect of the physical parameterizations and the land surface on rainfall in Poland",2016,"10.1175/WAF-D-15-0124.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84984605117&doi=10.1175%2fWAF-D-15-0124.1&partnerID=40&md5=2973d7b01184a378368409dd76646ec0","High-resolution numerical experiments were conducted over two separate months to study the effect of different physical parameterizations and different representations of the land surface on the prediction of rainfall events in Poland. The Coupled Ocean-Atmosphere Mesoscale Prediction System (COAMPS) was used with 2-km grid spacing. Four sets of forecast experiments were performed. The control experiment used a slab model for the surface energy budget, a Lin-based moist physics parameterization, and a Mellor and Yamada (MY) based turbulent kinetic energy (TKE) parameterization; the Louis experiment used a version of the Louis TKE parameterization in place of MY; the LSM experiment used the Noah land surface model (LSM) in place of the slab model; and the Thompson experiment used the Thompson microphysics parameterization instead of the Lin-based microphysics. The forecasts were validated against surface and upper-air observations, as well as radar reflectivity. The Louis parameterization yielded improvements to the total rainfall and small improvements to the near-surface temperature and moisture. The Noah LSM yielded the largest improvements to the prediction of near-surface temperature and moisture, and while it led to correctly forecasting an increase in precipitation in one month, it erroneously predicted a decrease in precipitation in the other month. The Thompson microphysics produced the most skillful precipitation forecasts for late spring, but produced precipitation forecasts that were less skillful than the control experiment for early fall. The use of higher horizontal resolution (0.5 km) for two rain events led to the overprediction of rainfall, but suggested a better distribution of the rainfall. © 2016 American Meteorological Society."
"36614005700;16639472200;36614190000;56249947100;","A comparison between sounding data and WRF forecasts at APEX site",2011,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-84878276205&partnerID=40&md5=2b64bc10c664251c051b07e0201858f5","Five WRF configurations using different soil model, microphysics and planetary boundary layer parameteri-zations are compared with sounding data launched during a field campaign at APEX (Atacama Pathfinder EXperiment) site. The WRF model does a very good job forecasting PWV and temperature, wind speed and direction vertical profiles over the APEX site. Changes in microphysics parameterizations do not produce appreciable changes in humidity profiles. The Noah land surface model greatly improves the forecasts compared to the 5-layer thermal diffusion scheme. The analysis of daily synoptic conditions shows that difficulties in predicting the diurnal variation of wind direction in clear conditions and the occurrence of dry shallow layers in the atmosphere are some of the error sources in forecasts. © 2011: Instituto de Astronomía, UNAM - Astronomical Site Testing Data in Chile Ed. M. Curé, A. Otárola, J. Marín, & M. Sarazin."
"57216211231;7005685786;","Impacts of cloud-system resolving regional modeling on the simulation of monsoon depressions",2010,"10.1029/2010GL042734","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85073451841&doi=10.1029%2f2010GL042734&partnerID=40&md5=0e469450ed22a7d59baa159f05ee5b11","The impacts of high-resolution (<10 km) and cloud-system-resolving regional modeling (CSRM) on the simulation of an intense south Asian monsoon depression (MD) were examined using the WRF-ARW model. Spatial resolution in this range was necessary to realistically simulate the MD's propagation, intensity, and precipitation. Simulations were however highly sensitive to the moist convection and cloud microphysics. The best scenarios were created by the microphysics parameterization (MP) that generated the most robust post-landfall condensation associated with the MD, alone or in combination with the cumulus parameterization that triggered vigorous convection overland in the coarser setup. A sensitivity study of the MP schemes in CSRM suggested that more sophisticated mixed-phased schemes contributed to higher simulation fidelity. Insufficient condensation and weak convection overland might induce spurious low systems over the Bay of Bengal through low-level moisture advection, which further interfered with the MD and degraded several simulations. Copyright 2010 by the American Geophysical Union."
"56199108100;57193426010;14009218600;7405583557;","Simulation of Arctic surface radiation and energy budget during the summertime using the single-column model",2008,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-42149167485&partnerID=40&md5=95de7e87979625fcac8549642f0fc3ca","The surface heat budget of the Arctic Ocean (SHEBA) project has shown that the study of the surface heat budget characteristics is crucial to understanding the interface process and environmental change in the polar region. An arctic single - column model (ARCSCM) of Colorado University is used to simulate the arctic surface radiation and energy budget during the summertime. The simulation results are analyzed and compared with the SHEBA measurements. Sensitivity analyses are performed to test microphysical and radiative parameterizations in this model. The results show that the ARCSCM model is able to simulate the surface radiation and energy budget in the arctic during the summertime, and the different parameterizations have a significant influence on the results. The combination of cloud microphysics and RRTM parameterizations can fairly derive the surface solar shortwave radiation and downwelling longwave radiation flux. But this cloud microphysics parameterization scheme deviates notably from the simulation of surface sensible and latent heat flux. Further improvement for the parameterization scheme applied to the Arctic Regions is necessary."
"29567694100;7102866124;56646005400;36720575300;57195996304;56100422000;","Cloud-resolving model applied to nowcasting: An evaluation of radar data assimilation and microphysics parameterization",2020,"10.1175/WAF-D-20-0017.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85096106873&doi=10.1175%2fWAF-D-20-0017.1&partnerID=40&md5=bf52bb00620ca6a020daec49de6f3369","This research explores the benefits of radar data assimilation for short-range weather forecasts in south-eastern Brazil using the Weather Research and Forecasting (WRF) Model’s three-dimensional variational data assimilation (3DVAR) system. Different data assimilation options are explored, including the cycling frequency, the number of outer loops, and the use of null-echo assimilation. Initially, four microphysics parameterizations are evaluated (Thompson, Morrison, WSM6, and WDM6). The Thompson parameterization produces the best results, while the other parameteri-zations generally overestimate the precipitation forecast, especially WDSM6. Additionally, the Thompson scheme tends to overestimate snow, while the Morrison scheme overestimates graupel. Regarding the data assimilation options, the results deteriorate and more spurious convection occurs when using a higher cycling frequency (i.e., 30 min instead of 60 min). The use of two outer loops produces worse precipitation forecasts than the use of one outer loop, and the null-echo assimilation is shown to be an effective way to suppress spurious convection. However, in some cases, the null-echo assimilation also removes convective clouds that are not observed by the radar and/or are still not producing rain, but have the potential to grow into an intense convective cloud with heavy rainfall. Finally, a cloud convective mask was implemented using ancillary satellite data to prevent null-echo assimilation from removing potential convective clouds. The mask was demonstrated to be beneficial in some circumstances, but it needs to be carefully evaluated in more cases to have a more robust conclusion regarding its use. © 2020 American Meteorological Society. FPolicy (www.ametsoc.org/PUBSReuseLicen."
"57211603751;15047538100;15050523700;6602135370;36242447900;57217228876;","Role of convective and microphysical processes on the simulation of monsoon intraseasonal oscillation",2020,"10.1007/s00382-020-05387-z","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85088862293&doi=10.1007%2fs00382-020-05387-z&partnerID=40&md5=3b87c7b55e7c5289a5206c9f66e71902","The study explores the role of ice-phase microphysics and convection for the better simulation of Indian summer monsoon rainfall (ISMR) and monsoon intraseasonal oscillation (MISO). Sensitivity experiments have been performed with coupled climate model- CFSv2 using different microphysics (with and without ice phase processes) and convective [Simple Arakawa Schubert (SAS), new SAS (NSAS)] parameterization schemes. Results reveal that the ice phase microphysics parameterization scheme performs better in the simulation of active and break composites of the ISMR as compared to ice-free runs. The difference between ice (ICE) and ice-free run (NOICE) can be attributed to the availability of copious cloud condensate at the upper level. Better representation of upper-level cloud condensate in ICE run (i.e., with ice phase microphysics) leads to correct representation of specific humidity in active and break spells. Proper depiction of upper-level cloud condensate further leads to realistic modulation of atmospheric circulation and better simulation of convection (as represented by OLR) in active and break spells of ICE run. As a result, better simulation of active and break occurs in the ICE run. In contrast, NOICE run (i.e., with warm phase microphysics) fails to depict upper-level cloud condensate in the active phase. It leads to an improper representation of specific humidity. Circulation features are also unrealistic, and convection is suppressed in the active phase. As a result, the active phase is not adequately simulated in the NOICE run. NOICE run composites during active spells depict the overestimation of the ascending branch of Hadley circulation as compared to MERRA reanalysis, which is relatively better in ICE run. NOICE run composites during active spells depict the overestimation of the ascending branch of Walker circulation as compared to MERRA reanalysis, which is further improved in ICE runs. The north–south space–time spectra of daily rainfall anomaly are also better captured by ICE run as compared to NOICE run. Results indicate that ice-phase processes are more important for capturing the difference between active and break composites, while convection parameterization is relatively more important for the intraseasonal variance analyses. Further improvements in ice microphysics parameterization with better convection schemes in models will be helpful for the betterment of MISO and will lead to the improved simulation of monsoon. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature."
"10144282600;8687063000;57212215393;35228711600;7004713805;","Cascading Toward a Kilometer-Scale GCM: Impacts of a Scale-Aware Convection Parameterization in the Goddard Earth Observing System GCM",2020,"10.1029/2020GL087682","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85090845731&doi=10.1029%2f2020GL087682&partnerID=40&md5=087beac7578f8140724cf839ff6e657f","The National Aeronautics and Space Administration (NASA) Goddard Earth Observing System global circulation model (GCM) is evaluated through a cascade of simulations with increasing horizontal resolution. This model employs a nonhydrostatic dynamical core and includes a scale-aware, deep convection parameterization (DPCP). The 40-day simulations at six resolutions (100 km to 3 km) with unvarying model formulation were produced. At the highest resolution, extreme experiments were carried out: one with no DPCP and one with its scale awareness eliminated. Simulated precipitation, radiative balance, and atmospheric thermodynamic and dynamical variables are well reproduced with respect to both observational and reanalysis data. As model resolution increases, the convective precipitation smoothly transitions from being mostly produced by the convection parameterization to the cloud microphysics parameterization. However, contrary to current thought, these extreme cases argue for maintaining, to some extent, the scale-aware DPCP even at 3-km scale, as the run relying solely on explicit grid-scale production of rainfall performs more poorly at this resolution. ©2020. American Geophysical Union. All Rights Reserved. This article has been contributed to by US Government employees and their work is in the public domain in the USA."
"57202789516;7006422317;57202789763;57193886077;56724696200;36724322000;","Assessing the performance of cloud microphysical parameterization over the Indian region: Simulation of monsoon depressions and validation with INCOMPASS observations",2020,"10.1016/j.atmosres.2020.104925","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85080042262&doi=10.1016%2fj.atmosres.2020.104925&partnerID=40&md5=d88da9d295f8cf93924a23c58886396d","This study validates the performance of four different cloud microphysics parameterization (CMP) with the INCOMPASS aircraft observations during monsoon 2016 and assesses its impact on simulations of two monsoon depressions (MDs) using the Weather Research and Forecasting (WRF) model. The simulations are carried out with a lead time up to 96 h. It is found that the Aerosol Aware Thompson (AAT) scheme showed better result in terms of wind and the WRF Double Moment Six Class microphysical scheme (WDM6) showed better correlations for temperature and dew point temperature compared to aircraft measurements. It is noted that the choice of CMP significantly impacts the key characteristics of the MDs such as rainfall, wind, temperature, hydrometeors and associated convective processes (e.g. moist static energy, moisture convergence). In general, CMPs have overestimated the rainfall compared to satellite estimates Tropical Rainfall Measuring Mission (TRMM), with WDM6 producing the least errors. Therefore, inter-comparisons of simulations of CMPs are carried out using WDM6 as the benchmark. Inter-comparison results suggest that there is a substantial reduction in rainfall for the Morrison due to drier lower and middle troposphere leading to subdued convective activity compared to others. Further, WDM6 has produced the least errors in the distribution of frozen hydrometer compared to ERA5. By examining the water budget, it is found that moisture convergence is the major driver for the rainfall, and the magnitude of moisture convergence is strongly affected by the choice of CMPs. Additionally, the local and advection terms of the moisture budget equation provide minimal contributions towards rainfall generation. © 2020"
"56893768100;56520921400;51864663400;57136738600;15848674200;","Microphysical Sensitivity of Superparameterized Precipitation Extremes in the Contiguous United States Due to Feedbacks on Large-Scale Circulation",2020,"10.1029/2019EA000731","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85088580560&doi=10.1029%2f2019EA000731&partnerID=40&md5=3510fdbd18c5ba331e9bc4fec23137e7","Superparameterized (SP) global climate models have been shown to better simulate various features of precipitation relative to conventional models, including its diurnal cycle as well as its extremes. While various studies have focused on the effect of differing microphysics parameterizations on precipitation within limited-area cloud-resolving models, we examine here the effect on contiguous U.S. (CONUS) extremes in a global SP model. We vary the number of predicted moments for hydrometeor distributions, the character of the rimed ice species, and the representation of raindrop self-collection and breakup. Using a likelihood ratio test and accounting for the effects of multiple hypothesis testing, we find that there are some regional differences, particularly during spring and summer in the Southwest and the Midwest, in both the current climate and a warmer climate with uniformly increased sea surface temperatures. These differences are most statistically significant and widespread when the number of moments is changed. To determine whether these results are due to (fast) local effects of the different microphysics or the (slower) ensuing feedback on the large-scale atmospheric circulation, we run a series of short, 5-day simulations initialized from reanalysis data. We find that the differences largely disappear in these runs and therefore infer that the different parameterizations impact precipitation extremes indirectly via the large-scale circulation. Finally, we compare the present-day results with hourly rain gauge data and find that SP underestimates extremes relative to observations regardless of which microphysics scheme is used given a fixed model configuration and resolution. ©2020. The Authors."
"57217228358;55713076400;","Effects of Microphysical Processes on the Precipitation Spectrum in a Strongly Forced Environment",2020,"10.1029/2020EA001190","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85086834001&doi=10.1029%2f2020EA001190&partnerID=40&md5=a3fb94a53515710ca01653ca51e03eea","This study investigates the effects of microphysical processes on the precipitation spectrum in a strongly forced environment using the vector vorticity cloud-resolving model (VVM). Experiments are performed under imposed advective cooling and moistening with two microphysics parameterizations: the predicted particle properties scheme (P3) and Lin scheme (VVM-Lin). Even though the domain-averaged precipitation is similar in the two experiments, P3 exhibits stronger extreme precipitation in the spectrum compared with VVM-Lin. Changes in convective structures are responsible for such a difference. Using the isentropic analyses, we identify that in P3, stronger convective updrafts take place in the high θei regime, where air parcels rarely reach. This is caused by the reduced melting of rimed ice particles for energic parcels. Through defining convective core clouds, the relation between the convective structure on the isentropic diagram and the extreme precipitation can be identified. The shifts toward extreme intensity in the precipitation spectrum suggest that the microphysical processes have significant impacts on the extreme precipitation by the convective core clouds. The treatment of microphysics has significant impacts on the convective structures and then alter the probability of extreme events under the strongly forced environment. © 2020. The Authors."
"57217282516;57190136413;57211435162;57217401404;57211446010;14051057200;7801602398;","Influence of cumulus convection and cloud microphysics parameterizations on the prediction of Western Disturbances",2020,"10.1007/s00703-019-00697-2","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85073946635&doi=10.1007%2fs00703-019-00697-2&partnerID=40&md5=6343b5a1b015ac51ca7209be24d45c82","The western disturbances (WD) form over the Mediterranean region as extra-tropical low-pressure systems and lose the frontal structure while moving eastward to reach India. These systems bring cold waves, snowfalls, hailstorms and rain over north and north-west India during post monsoon and winter months. The first part (Part A) of the present paper investigates the performance of Advanced Research WRF (ARW) model with 8 combinations of cloud microphysics and cumulus convection schemes in simulating 20 WD cases. These 20 cases were simulated using a single-domain WRF model of horizontal resolution 27 km. The combination of Lin et al. cloud microphysics scheme and Betts–Miller–Janjic cumulus convection scheme (mp2cu2) performs better than other combinations in simulating temperature at 2 m height and precipitation. The performance of the combination of Ferrier (new Eta) microphysics scheme and Betts-Miller-Janjic cumulus convection scheme (mp3cu2) is very close to that of mp2cu2 combination. Analysis of box-whisker plot also shows that the combinations mp2cu2 and mp3cu2 perform better than others. In the second part (Part B) 10 cases are simulated using a double-nested WRF model with inner and outer domain resolutions 9 km and 27 km, respectively. Four cases of part B are simulated with (mp2cu2 and mp3cu2) and without (mp2cu0 and mp3cu0) cumulus convection schemes to understand the response of cloud microphysics to explicit convection and also to select the best combination of cloud microphysics and cumulus convection scheme. The combination mp2cu2 has lower RMSE of precipitation than other combinations. Remaining six cases were then simulated with the combination of mp2cu2 using the double-nested model. Spatial distribution of model simulated and TRMM estimated precipitation agree well in most of the cases. The domain-averaged RMSE of model-simulated precipitation with respect to TRMM 3B42 V7 estimated precipitation varies from 2.89 to 4.12 cm for the six WD cases. The box-whisker diagram shows that the model overestimates the maximum rainfall amount in most of the cases but it is consistent in simulating precipitation over the model domain for all the six cases. © 2019, Springer-Verlag GmbH Austria, part of Springer Nature."
"56939487800;7403352662;57216241620;13404502400;","Passive Microwave Precipitation Retrieval Algorithm with A Priori Databases of Various Cloud Microphysics Schemes: Tropical Cyclone Applications",2020,"10.1109/TGRS.2019.2948262","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85082883701&doi=10.1109%2fTGRS.2019.2948262&partnerID=40&md5=ba990036aaccd74cba7e005e809ef850","The accuracy of a physically based passive microwave precipitation retrieval algorithm is affected by the quality of the a priori knowledge it employs, which indicates the relationship between the precipitation information obtained from cloud-resolving models (CRMs) and the simulated brightness temperatures (TBs) from radiative transfer models. As various microphysical assumptions reflecting a wide variety of sophisticated microphysical properties are applied to the CRMs, the TBs simulated based on the model-driven 3-D precipitation fields are determined by the selected microphysical assumption. In this article, we developed a prototype precipitation retrieval algorithm that incorporates various cloud microphysics schemes in its a priori knowledge (i.e., databases). In the retrieval process, a specific a priori database is selected for every target precipitation scene by comparing the similarities of the simulated and observed microwave emission and scattering signatures. The prototype algorithm was tested through application to precipitation retrieval for tropical cyclones at various intensity stages, which occurred over the northwestern Pacific region in 2015. The a priori databases constructed using the weather research and forecasting double-moment (WDM6) and Thompson Aerosol Aware schemes are superior when used for weak-to-moderate rainfall systems, whereas the databases constructed with the other schemes are superior within strong rain rate regions. The retrieval results obtained using the best-performing database are generally superior for all rain rate regions. Furthermore, we confirm that the database quality is more important than the number of databases. In comparison with the data from the dual-precipitation radar, the retrieval's correlations, bias, and root mean square are 0.75, 0.14, and 5.62, respectively. © 2019 IEEE."
"57195056873;55277641000;57208383202;57208884909;","Assessing the Effects of Microphysical Scheme on Convective and Stratiform Characteristics in a Mei-Yu Rainfall Combining WRF Simulation and Field Campaign Observations",2020,"10.1155/2020/8231320","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85082664264&doi=10.1155%2f2020%2f8231320&partnerID=40&md5=5d9d129e1e32c9c00f509c8df9e4e69c","Microphysics parameterization becomes increasingly important as the model grid spacing increases toward convection-resolving scales. Using observations from a field campaign for Mei-Yu rainfall in China, four bulk cloud microphysics schemes in the Weather Research and Forecasting (WRF) model were evaluated with respect to their ability to simulate precipitation, structure, and cloud microphysical properties over convective and stratiform regimes. These are the Thompson (THOM), Morrison graupel/hail (MOR_G/H), Stony Brook University (SBU_YLIN), and WRF double-moment six-class microphysics graupel/hail (WDM6_G/H). All schemes were able to predict the rain band but underestimated the total precipitation by 23%-35%. This is mainly attributed to the underestimation of stratiform precipitation and overestimation of convective rain. For the vertical distribution of radar reflectivity, many problems remain, such as lower reflectivity values aloft in both convective and stratiform regions and higher reflectivity values at middle level. Each bulk scheme has its advantages and shortcomings for different cloud regimes. Overall, the discrepancies between model output and observations mostly exist in the midlevel to upper level, which results from the inability of the model to accurately represent the particle size distribution, ice processes, and storm dynamics. Further observations from major field campaigns and more detailed evaluation are still necessary. © 2020 Lin Liu et al."
"15050523700;15047538100;36242447900;6602135370;57211603751;36006968000;","Role of cloud microphysics in improved simulation of the Asian monsoon quasi-biweekly mode (QBM)",2020,"10.1007/s00382-019-05015-5","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85074567884&doi=10.1007%2fs00382-019-05015-5&partnerID=40&md5=9602653b48a3b7d5cb355f2b5dd210fc","A major sub-seasonal variability of the tropics and sub-tropics, the quasi-biweekly mode (QBM), is known to have significant influence on the seasonal mean of the south Asian monsoon rainfall. A coupled Atmosphere–Ocean General Circulation Model (AOGCM) being essential for seasonal prediction, the ability of the AOGCMs in simulating the space–time characteristics with fidelity is critical for successful seasonal prediction of the south Asian monsoon in particular and seasonal prediction in the tropics in general. However, strength and weaknesses in simulating the QBM by AOGCMs have remained poorly investigated so far. Here, we examine the simulation of the QBM in AOGCM and show that improvement of parameterizations of both convection and microphysics is required to improve the simulation of the QBM. While the standard version of the model overestimates the variance of QBM and simulates a smaller scale Rossby waves (n = 1), the modified version of the model where the simple Arakawa–Schubert (SAS) convection parameterization is combined with a new improved microphysics parameterization (MCMv.1) proposed by us, simulates a more realistic space–time characteristics of the QBM. In yet another version of the model, we combine the new SAS with the new improved microphysics parameterization. Interestingly, this version of the model also simulates the space–time structure poorly with poor westward propagation and fragmented organization, but it simulates a reasonable variance. These results indicate that a synergy among the convective parameterization and microphysics parameterizations is critical in simulating the QBM in particular and equatorial waves in general. We show that most the biases in simulating the QBM may be related to the biases of the model in simulating the stratiform fraction of precipitation. While the simulation of the space–time characteristics of QBM is better simulated in the MCMv.1, the convective coupling is still too strong as compared to observations, an area for future improvement of the model. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature."
"7202157381;56651680700;","Impact of cloud microphysical processes on the dynamic downscaling for western himalayas using the WRF model",2019,"10.1007/978-3-030-29684-1_6","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85085440106&doi=10.1007%2f978-3-030-29684-1_6&partnerID=40&md5=89e6b3dc9e10a51067c6a1facc44c34f","Dynamic downscaling of climate is a useful procedure to downscale the climate especially over the data sparse regions of the Himalayas. The global reanalysis data are too coarse to represent the hydroclimate over the regions with sharp orography gradient in the western Himalayas. The present study attempts to carry out dynamic downscaling of ERA-Interim dataset (January to May) over the western Himalayas using the weather research and forecasting (WRF) model. Sensitivity studies have been carried out using four microphysics parameterization schemes (namely WSM3, WSM6, Morrison and Thompson schemes). It is seen that the model is able to simulate large scale patterns of precipitation, temperature and winds reasonably well. The impact of the Morrison and Thompson schemes is to shift the zone of maximum precipitation more downwind as compared to WSM6 during winter. The WSM6 favors precipitation on the slopes of the terrain, Morrison and Thompson schemes simulate more precipitation on the mountain top (more snow) as the snow particles get advected more downwind. The Morrison scheme simulates less amount of graupels over the region than the WSM6. The narrow zone of sharply rising orography is the area where the WSM6 scheme simulates more rain than the Morrison scheme. This study emphasizes that a correct representation of the microphysical processes in the models is crucial for long-term climate simulations for correct representation of partitioning atmospheric water into vapor, cloud liquid water, cloud ice etc. leading either to solid or liquid precipitation. © Springer Nature Switzerland AG 2020. All rights reserved."
"7005872245;7201398636;6602134507;7005868133;","On the importance of a consistent treatment of prognostic moisture variables between convective and microphysical parameterizations",2018,"10.1175/MWR-D-17-0305.1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047055981&doi=10.1175%2fMWR-D-17-0305.1&partnerID=40&md5=24bb7faf273c32cc1f8f752e05b2b023","Analysis of WRF Model output from experiments using two double-moment microphysics schemes is carried out to demonstrate that there can be an inconsistency between the predicted mass and number concentrations when a single-moment convective parameterization is used together with a double-moment microphysics scheme. This inconsistency may arise because the grid-scale and subgrid-scale cloud schemes generally apply different levels of complexity to the parameterized microphysical processes. In particular, when a multimoment formulation is used in the microphysics scheme and other physical parameterizations modify only the mass-related moment while the values of the second (or higher) moment for individual hydrometeors remain unchanged, an unintended modification of the particle size distribution occurs. Simulated radar reflectivity is shown to be a valuable tool in diagnosing this inconsistency. In addition, potential ways to minimize the problem are explored by including number concentration calculations in the cumulus parameterization that are consistent with the assumptions of hydrometeor sizes in the microphysics parameterization. The results of this study indicate that it is physically preferable to unify microphysical assumptions between the grid-resolved and subgrid cloud parameterization schemes in weather and climate simulation models. © 2018 American Meteorological Society."
"54902712400;23490592400;55861417200;","High-resolution WRF simulation of cloud properties over the super typhoon Haiyan: physics parameterizations and comparison against MODIS",2016,"10.1007/s00704-015-1575-y","https://www.scopus.com/inward/record.uri?eid=2-s2.0-84938819765&doi=10.1007%2fs00704-015-1575-y&partnerID=40&md5=93d5f6a82b54bf6e2d6a0c24d8baaa99","Numerical weather prediction (NWP) models can complement the satellite technology in simulating the cloud properties, especially in extreme storm events, when gathering new data becomes more than essential for accurate weather forecasting. In this study, we investigate the capability of the Weather Research and Forecasting (WRF) model to realistically simulate some important cloud properties in high-resolution grids, such as cloud phase (e.g., liquid or ice) and cloud water path. The sensitivity of different combinations of physics parameterizations to the simulated cloud fields is studied. The experiment is conducted on a super typhoon event by configuring the WRF model in two domains, with two-way nesting, allowing bidirectional information exchange between the parent and the nest. In order to do the assessment, the simulated cloud fields are compared against MODIS-derived cloud properties from one overpass scene. While the simulations have been able to capture the spatial distribution of cloud properties reasonably well, produced cloud quantities such as ice water path has been significantly overestimated when compared to the MODIS optical cloud information. The microphysics parameterizations are found to be more sensitive than the planetary boundary layer (PBL) parameterizations. © 2015, Springer-Verlag Wien."
"25953950400;57210719777;6505932008;","The Parameterization or Modeling of Microphysical Processes in Clouds",2011,"10.1016/S0074-6142(10)09910-9","https://www.scopus.com/inward/record.uri?eid=2-s2.0-77957771813&doi=10.1016%2fS0074-6142%2810%2909910-9&partnerID=40&md5=d8e1d7b4333ff9b87139cfb29fa24304","Chapter 4 provides an overview of the general theory of cloud precipitation processes. We then review cloud microphysics parameterization methodologies. We conclude but summarizing how cloud microphysics impacts cloud dynamics. © 2011 Elsevier Ltd."
"56818716000;7102353054;18436976900;","Simulation of monsoon precipitation over south-Asia using RegCM3",2007,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-77952890779&partnerID=40&md5=dabd70a7a910a0ffbc2157710e4661a6","The objective of this study was to explore the capability of the regional climate model RegCM3, to predict extreme weather events in south-Asia region with particular reference to precipitation during monsoon season (July, August, September) over northern mountainous and southern plain regions of Pakistan. Different cumulus parameterization schemes in RegCM3 for prediction of convective precipitation were tested for monsoon period during the years 1998 and 2001. The model predicted results compared with the satellite pictures, CRU observational data and the surface synoptic observatories data of the Pakistan Meteorological Department (PMD). This may be mentioned here, that the year 1998 was a dry year and the starting year of a severe drought which lasted up to the year 2000. This may also be added here, that during the year 2001, the precipitation over some parts of the country exceeded the normal and some areas in the northern parts of the country observed exceptionally high rainfall rate. The results indicated that some convective parameterization schemes of RegCM3, well captured the summer monsoon precipitation over south-Asia region. However, the schemes need to be selected carefully depending upon the region of any particular focus. Some interim findings were that the Grell scheme with both closures: Arakawa-Schubert (AS) and Fritsch-Chappell (FC) satisfactorily predicted the total monthly rainfall in the northern mountainous regions of Pakistan. However, both predicted high precipitations over southern and south-eastern plain regions. Both the modified-Kuo and Betts-Miller (BM) schemes substantially under-predicted the rainfall, although the patterns were captured adequately. The modified-Kuo scheme was more close to the observed data when compared with the performance of the BM scheme It is recommended to further test the model schemes, perhaps a further improvement in the modified-Kuo scheme would yield a scheme even better than both of the Grell closures (which predicted exceptionally high precipitation over south-eastern plain regions of Pakistan and the adjoining Indian regions. In a future paper we shall be presenting more results and will try to suggest some modifications in the existing schemes to be able to better capture the summer monsoon precipitation over south-Asia. Due to their coarse resolution General Circulation Models (GCMs) often perform poorly in simulating regional processes, especially in regions with local fine-scale forcing topography (Gates, 1992, Gao et al., 2002). On the other hand, modeling studies with regional climate models also indicated that some cumulus parameterization schemes do not perform well in some specific regions of the world e.g. Asian monsoon regions (Leung et al. 2003, Lee and Suh 2000). Scale interactions are extremely complex in the Asian monsoon regions (Holland 1995), which are further complicated due to the effects of Tibetan plateau, ocean-continent contrast and sea-air interactions. These specific features require special consideration in designing regional climate models to be used in this particular region. The impacts of climate change on food and water resources of a country are linked with the regional climate rather than to the global scale. It is therefore imperative to understand and predict how global climate change is manifested at these regional scales. Using GCM output to drive limited-area atmospheric simulations on regional scales has been reported to be a promising approach for simulating regional climates (Giorgi and Mearns, 1991, 1999). The principle behind this approach is that, given a large-scale atmospheric circulation, a limited-area model with a suitably high-resolution, resolving complex topography, land-sea contrast, land use and detailed description of physical processes can generate realistic high-resolution (both spatial and temporal) information coherent with the driving large-scale circulation. The large-scale circulation can be supplied by either reanalysis data or a GCM output. A critical weakness that needs improvement in both global and regional climate models is the treatment of clouds (Giorgi and Mearns 1999). Although the detailed explicit cloud microphysics parameterization for grid resolved moist processes, is considered in some of the regional climate models, the complex interaction between sub-grid cumulus convection and grid scale moist processes is very crudely treated. Some studies have indicated the improvements in radiation budgets by using cloud microphysics information (Petch and Dudhia, 1998), but the cloud amount is treated in a quite simple way and is usually estimated by the relative humidity in most of the climate model applications (Giorgi et al. 1993, Dudek et al. 1996, Wang et al. 2000). Although some previous studies (Houghton et al., 1992) have shown the capability of regional climate models in reproducing intra-annual variability when driven by good quality driving fields, more analyses are needed to improve model performance in simulating climate variability at short timescales (days to weeks). The increased resolution of regional climate models can allow simulation of a broader spectrum of weather events to improve simulation of the daily to monthly precipitation intensity distributions. We in this work, have studied the capabilities of a regional climate model, RegCM3 (available from http://www.ictp.trieste.it/~pubregcm/RegCM3) to simulate the precipitation intensity/patterns during summer monsoon season in the Indian subcontinent. The summer monsoon systems are originated from the Bay of Bengal, Indian Ocean and some times get accentuated by the juxtaposition of passing westerly disturbances and the Arabian Sea component. We have tried to identify some suitable cumulus parameterization schemes for predicting the summer monsoon precipitation (July to September) over the regions or to access the need of further modification in the model. Different cumulus parameterization schemes in RegCM3 for prediction of convective precipitation were tested for monsoon period during the years 1998 and 2001. This would be interesting to mention here that 1998 was the starting year of a severe drought in Pakistan, which lasted up to the year 2000. Due to this drought the agricultural productivity in the country was badly affected. On the other hand, during the year 2001, the precipitation over some parts of the country exceeded the normal and some areas in the northern parts of the country observed exceptionally high rainfall rate. July 23, of the year 2001 witnessed heavy rainfall in a cloud burst fashion over some of the northern parts of Pakistan (Districts of Mansehra, Abottabad, Rawalpindi and Islamabad). This heavy precipitation exceeded the recorded maximum rainfall in Islamabad, during a single spell and caused severe economic and life loss. In this work, we have tried to explore the capabilities of RegCM3 and the effects of the use of different convective closure schemes on the intensity and spatial patterns of the precipitation during the summer monsoon months (July, August and September) of the selected years. The model was initialized using the NCEP reanalysis data having spatial resolution of 2.5° × 2.5° and temporal resolution of 6 h. The model domain was from 5N to 45N and 55E to 105E with a spatial resolution of 90 km and a 1:3 nesting was provided over a domain from 24N to 36N and 60E to 76E to focus on Pakistan. USGS Topographic data and US Department of Agriculture, land use data of 10 minutes resolution were used (see Figs. 1-2)."
"7404805734;7202484836;7102201685;","Scaling the Microphysics Equations and Analyzing the Variability of Hydrometeor Production Rates in a Controlled Parameter Space",2002,"10.1007/s00376-002-0004-1","https://www.scopus.com/inward/record.uri?eid=2-s2.0-0346044578&doi=10.1007%2fs00376-002-0004-1&partnerID=40&md5=88eb7efe04b8fd8b120fb91883a25116","A set of microphysics equations is scaled based on the convective length and velocity scales. Comparisons are made among the dynamical transport and various microphysical processes. From the scaling analysis, it becomes apparent which parameterized microphysical processes present off-scaled influences in the integration of the set of microphysics equations. The variabilities of the parameterized microphysical processes are also studied using the approach of a controlled parameter space. Given macroscopic dynamic and thermodynamic conditions in different regions of convective storms, it is possible to analyze and compare vertical profiles of these processes. Bulk diabatic heating profiles for a cumulus convective updraft and downdraft are also derived from this analysis. From the two different angles, the scale analysis and the controlled-parameter space approach can both provide an insight into and an understanding of microphysics parameterizations."
"56216811200;7003885275;7202537315;","Numerical simulations of turbulence in convective clouds",2000,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-84894379984&partnerID=40&md5=c769fd59b60e89395caf03b6b63f3081","Results of several three-dimensional, high resolution numerical simulations of convective clouds and the model generated turbulence locations and intensities within the clouds are presented, and the model results compared to actual observations gathered in field programs. Gross properties of the cloud appear to be correctly captured by the model. However, turbulence locations and intensities were found to be sensitive to details of the cloud microphysics parameterizations. Wind and turbulence fields from these simulations are being used as input into radar turbulence algorithms and for aircraft response studies as part of the NASA Aviation Safety Program. © 1999 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved."
"7403590856;6701873414;7410372222;","4DVAR assimilation of multi-parameter radar observations in an explicit cloud model",1997,,"https://www.scopus.com/inward/record.uri?eid=2-s2.0-0031343223&partnerID=40&md5=6700aaca9dc3e37d1b284c0613d8ef8c","A four-dimensional variational (4DVAR) data assimilation technique, based on an anelastic model and its adjoint, is used to retrieve the wind, temperature, pressure and microphysical fields in moist convective systems from single or multiple-Doppler radar observation. The microphysical parameterization in this model incorporated the liquid phase physics. This model is applied to a severe thunderstorm observed during the MIST experiment. Observations have indicated that ice process played a significant role in the precipitation processes in its life-time period. To have a better microphysical retrieval, the differential reflectivity (ZDR) observation from the multi-parameter radar (CP2) is included."
"56122761300;6506806397;","Alternative solution to the problem of saturation adjustment in the presence of ice and water",1992,"10.1007/BF01613899","https://www.scopus.com/inward/record.uri?eid=2-s2.0-34249835087&doi=10.1007%2fBF01613899&partnerID=40&md5=2bd037ea8959172656492b4f65201844","In cloud microphysics parameterization schemes, explicitly involving the co-existence of cloud water and ice in a temperature interval, it is necessary to solve the question of saturation adjustment in the presence of the mixed phase. In the present paper we propose an iteration procedure, which reliably converges with a small number of iterations, to solve this problem. The procedure is applied to a 3-D prognostic mesoscale model being developed for studying the effect of the ice phase on precipitation forecasts. © 1992 Academia, Publishing House of the Czechoslovak Academy of Sciences."