Trace Gas Retrievals from the GeoTASO Aircraft Instrument During the DISCOVER-AQ Campaigns

The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) instrument is a recently-developed passive remote sensing instrument capable of making 2-D measurements of trace gases from aircraft. GeoTASO was developed under NASA's Instrument Incubator program and is a test-bed instrument for the Geostationary Coastal and Air Pollution Events (GEO-CAPE) decadal survey and the upcoming Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite missions. The instrument collects spectra of backscattered UV-visible radiation for the detection of tropospheric trace gases such as NO2, ozone, formaldehyde and SO2. GeoTASO flew on the NASA HU-25C Falcon aircraft during the 2013 (Texas) and 2014 (Colorado) DISCOVER-AQ field campaigns, making satellite-analog measurements of trace gases at a spatial resolution of approximately 500x500 m over urban areas, power plants and other industrial sources of pollution. We present the GeoTASO retrieval algorithms, trace gas measurement results, and validation comparisons with ground-based observations and other aircraft instruments during these campaigns.