Observations of atmospheric composition in fire plumes over the Western United States in summertime from the Cross-Track Infrared Sounder

Smoke from wildfires in the Western United States, has major impacts on air quality, nutrient cycles, weather and climate downwind from fires, even thousands of kilometers away. Satellite measurements from thermal infrared sounders can provide a wealth of information on the composition of fire plumes. Here, we present measurements of trace gases in wildfire plumes over the Western US from the Cross-Track Infrared Sounder (CrIS) on Suomi-NPP. We show single field-of-view results on the native 15 km resolution of the CrIS Level 1B radiances, processed using the optimal estimation Multi-Species, Multi-Spectral, Multi-Satellite (MUSES) algorithm.

We highlight results for two key reactive nitrogen species: peroxyacetyl nitrate (PAN), a thermally unstable reservoir for NOx that plays an important role in long-range pollution transport and the distribution of tropospheric ozone, and ammonia (NH₃), a precursor for particulate matter. We also show coincident CrIS measurements of carbon monoxide (CO) and ozone (O3). We focus on summer 2018, a time period that coincides with the Western wildfire Experiment for Cloud chemistry, Aerosol absorption and Nitrogen (WE-CAN) intensive flight campaign. The WE-CAN measurements provide opportunities for validation of the CrIS trace gas measurements, while the satellite measurements provide wider spatial context for areas and time periods not covered by aircraft campaigns, thus offering an opportunity to add to our understanding of the effects of biomass burning on the nitrogen cycle and ozone production.