uataq/X-STILT: X-STILT for TROPOMI and OCO-2/3

• Latest release on X-STILT in interpreting TROPOMI (use with cautions for NO2, no chemistry implemented yet) and OCO-2/3 data.
• README can be found at https://github.com/uataq/X-STILT/blob/master/README.md.
• Please always access the development version from https://github.com/uataq/X-STILT. Versions on Zenodo can be outdated.
• Please refer to the STILT tutorial https://github.com/uataq/stilt, if you are not familiar with our Lagrangian system.

Please contact Dien Wu (dienwu@caltech.edu) OR preferrably submit a pull request on GitHub (https://github.com/uataq/X-STILT) describing your specific error messages.

This version (v1.5) bookmarks the code version documented in the following manuscripts:

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.

Wu, D., Liu, J., Wennberg, P. O., Palmer, P. I., Nelson, R. R., Kiel, M., and Eldering, A.: Towards sector-based attribution using intra-city variations in satellite-based emission ratios between CO₂ and CO, Atmos. Chem. Phys. Discuss. [preprint], https://doi.org/10.5194/acp-2021-1029, accepted, 2022.