The spatial coverage provided by current satellites provides the opportunity to enhance our knowledge of atmospheric deposition through the fusion of the satellite observations with ground-based observations and air quality models.  Presented is a brief description of the recent Cross-Track Infrared Sounder (CrIS) satellite observations of ammonia (NH₃) (Shephard and Cady-Pereira, (2015)), and their initial evaluation against available ground-based observations (e.g. AMoN, NAPS, Fourier Transform Infrared (FTIR)).  Also provided are examples of how the CrIS NH₃ observations can be used for air quality model evaluation, and deriving emission estimates from large point sources and forest fires. Furthermore, we present recent results from an atmospheric deposition application combining CrIS and Ozone Monitoring Instrument (OMI) satellite observations with modelled deposition velocities to derive atmospheric dry deposition of reactive nitrogen from short-lived nitrogen species of ammonia and nitrogen dioxide (NO₂) (Kharol et al., 2018).   Some key findings from this application are that: (i) satellite estimates of NH₃ and NO₂ dry deposition indicate that the NH₃ dominates over most regions across the North America during the warm season, and (ii) locations at northern latitudes affected by forest fires tend to have 2–3 times more dry deposition of ammonia relative to the local background.  The same approach was applied to derive the atmospheric dry deposition of sulphur from sulphur dioxide (SO₂) using OMI observations.  We will also briefly discuss the increased capabilities of recently launched (e.g. TropOMI) and future satellites (e.g. TEMPO). 

Kharol, S. K., M. W. Shephard, C. A. McLinden, L. Zhang, C. E. Sioris, J. M. O’Brien,  R. Vet, K. E. Cady-Pereira, E. Hare, J. Siemons, and N. A. Krotkov,  Dry deposition of reactive nitrogen from satellite observations of ammonia and nitrogen dioxide over North America, Geophysical Research Letters, 45, 1157-1166, https://doi.org/10.1002/2017GL075832, 2018.

Shephard, M.W. and K.E. Cady-Pereira, Cross-track Infrared Sounder (CrIS) Satellite Observations of Tropospheric Ammonia, Atmos. Meas. Tech., 8, 1323–1336, doi:10.5194/amt-8-1323-2015, 2015.