Intercomparison of Tropospheric and Total Column Ozone of TRACER-AQ Data Sets with EPIC on DSCOVR Satellite

The Earth Polychromatic Imaging Camera (EPIC), attached to NASA’s DSCOVR satellite, provides hourly 0.25° x 0.25° measurements of total and tropospheric column ozone over most of North America and was active during the full month of September 2021, when the TRacking Aerosol Convection ExpeRiment–Air Quality (TRACER-AQ) campaign took place in the Houston Area. There were 62 ozonesondes launched during the campaign, Pandora spectrometer instruments collecting total column ozone measurements, two ground-based NASA TOLNet (Tropospheric Ozone Lidar Network) systems from Goddard Space Flight Center (GSFC, TROPOZ) and NASA Langley Research Center (LaRC, LMOL), as well flights from NASA’s G-V aircraft that had a downward facing High Spectral Resolution Lidar-2 (HSRL-2). We report on an intercomparison between the tropospheric and total column ozone measurements of these instruments and those of EPIC. The comparison of the LiDAR with EPIC and GEOS-CF is performed using a hybrid of the LiDAR measurements for the lower altitudes and the higher altitude ozonesonde measurements that were launched in coordination with G-V overpasses.The intercomparison between the sondes and EPIC showed good agreement for the height of the tropopause, however a relatively large error between the tropospheric column ozone measurements of the two. The Pandora intercomparisons showed good agreement with EPIC in the total column ozone, especially considering the large variability in total column ozone throughout the month.