2025 California Wildfire Observations Using Single Field‐of‐View Sounder Atmospheric Products (SiFSAP)

Abstract Southern California wildfires result in a significant loss for Los Angeles and San Diego County from January 7 to 31, 2025. Palisades Fire and Eaton fires, the two largest fires that caused most of that damage, were observed by the infrared sounder CrIS and microwave sounder ATMS aboard a polar‐orbit satellite of the National Oceanic and Atmospheric Administration, that is, NOAA‐20. The high spatial resolution Single Field‐of‐view Sounder Atmospheric Products (SiFSAP) retrieved from CrIS and ATMS measurement have been used to illustrate the emission and transport of the plume generated by the wildfires. The CO total column and UV aerosol index (UVAI) observed by TROPOMI, CO total column observed by AIRS, the aerosol optical thickness (AOT) provided by VIIRS, and wind provided by ERA5 were used to illustrate plume produced by wildfires. Furthermore, cloud optical depths and top pressures retrieved by SiFSAP and VIIRS were compared to assess the IR sounder's capability to retrieve clouds. Results indicated that the SiFSAP data products effectively capture not only large scale dry airmass transport but also the movement of wildfire‐generated plumes containing high CO concentrations. The study shows that the SiFSAP CO retrieved from IR measurements is less affected by aerosols as compared to solar measurements like TROPOMI. This study demonstrates that the SiFSAP products provides a high‐quality data set for wildfire observations and disaster observations.