uataq/X-STILT: X-STILT

This release includes the model code of X-STILT built on STILT-R version 2 (Fasoli et al., 2018) and STILT (Lin et al., 2003). Important changes from the last version v1.3 include X-STILT code refactoring with STILTv2 being a submodule along with few optimizations and minor changes:

• Refactor transport error code using the latest X-STILT framework (see run_xstilt). Specifically, move the traj-level CO2 calculation (starting with cal.trajfoot.stat()) into before_footprint_xstilt().

• Minor bugs/typos fixed (leading to very small impact on the calculation), when 1) weighting traj-level foot for trajec with wind error component (wgt.trajec.footv3) and 2) calculating the traj-level CO2 (cal.trajfoot.stat). Specifically, no AK weighting for endpts.trajfoot.r.

• Remove two sections of the code for simplifications, including 1) calculation of lat-int signals or errors in run_xstilt and 2) two scripts for plotting that used to be in ./r/src/plot_scripts.

• Optimize several functions for trajec-level CO2 calculations (*.trajfoot) to reduce the memory needed.

This version bookmarks the code version documented in the following manuscript: Wu, D., Lin, J. C., Fasoli, B., Oda, T., Ye, X., Lauvaux, T., Yang, E. G., and Kort, E. A.: A Lagrangian approach towards extracting signals of urban CO2 emissions from satellite observations of atmospheric column CO2 (XCO2): X-Stochastic Time-Inverted Lagrangian Transport model ("X-STILT v1"), Geosci. Model Dev., 11, 4843-4871, https://doi.org/10.5194/gmd-11-4843-2018, 2018.

Please refer to https://github.com/uataq/X-STILT for the latest updates. Please contact Dien Wu (Dien.Wu@utah.edu) if you have any questions, comments, and suggestions.