CrIS NH3 retrieval data used in EnsAI evaluation

This dataset contains the CrIS NH3 retrieval data that was used in the evaluation of the EnsAI ensenble generation system (Sitwell 2025). The files in this dataset contain gridded data files containing the innovation (retrieval minus model forecast) values for 2015 which were processed as described in Sitwell et al. 2022. This data is defined on the horizontal grid used by the EnsAI system, where values of NaN (not a number) indicate that retrievals were not available at that grid point for a particular time.

The user guide for the (unprocessed) CrIS NH3 retrievals is also included.

References:

Sitwell, M., Shephard, M. W., Rochon, Y., Cady-Pereira, K., and Dammers, E.: An ensemble-variational
inversion system for the estimation of ammonia emissions using CrIS satellite ammonia retrievals,
Atmospheric Chemistry and Physics, 22, 6595–6624, 2022.

Sitwell, M.: EnsAI: An Emulator for Atmospheric Chemical Ensembles, doi:
https://doi.org/10.5281/zenodo.15342768, 2025.