SCOAPE: Monitoring Offshore Air Quality Near Oil and Gas Operations in the Gulf of Mexico in May 2019

The Satellite Coastal and Oceanic Atmospheric Pollution Experiment (SCOAPE) was designed to assess the ability of satellite data to monitor air quality near oil and natural gas (ONG) operations in the Gulf of Mexico (GOM). SCOAPE is an Interagency Agreement between NASA and the Bureau of Ocean Energy Management (BOEM – Dept. of Interior), who are required to ensure that ONG operations do not significantly affect the onshore air quality of any State. We present results from the 10-18 May 2019 SCOAPE cruise campaign that sailed the GOM to collect in-situ and remotely-sensed air quality data for satellite validation (primarily NO₂). The R/V Point Sur encountered two contrasting air regimes during the cruise: an extremely clean air mass with remote tropical origins, and a more polluted regime with continental origins. The contrast is obvious in the in-situ trace gas and ozonesonde measurements. Total column NO₂ measurements from the Pandora spectrometer on land and on the Point Sur show good correlation with TROPOMI (TROPOspheric Monitoring Instrument) satellite data during both the clean and polluted regimes, although the satellite averages 15% low. Therefore, results are encouraging for the potential monitoring of air quality over GOM ONG operations with satellite data from TROPOMI, and eventually TEMPO (Tropospheric Emissions: Monitoring of Pollution). In addition, CH₄ (>15 ppmv; see in-situ CH₄ along cruise track in Figure 1) and volatile organic compound (benzene ~2 ppbv) canister measurements indicate that frequent natural gas leaks at shallow water platforms also have the strong potential to influence air quality over the GOM.