Satellite NO2 Trends and Hotspots over Offshore Oil and Gas Operations
in the Gulf of Mexico
Abstract
The Outer Continental Shelf of the Gulf of Mexico (GOM) is populated
with numerous oil and natural gas (ONG) platforms which produce NOx (NOx
= NO + NO2), a major component of air pollution. The Bureau of Ocean
Energy Management (BOEM) is mandated to ensure that the air quality of
coastal states is not degraded by these emissions. As part of a
NASA-BOEM collaboration, we conducted a satellite data-based analysis of
nitrogen dioxide (NO2) patterns and trends in the GOM. Data from the OMI
and TROPOMI sensors were used to obtain 18+ year records of tropospheric
column (TrC) NO2 in three GOM regions: 1) Houston urban area, 2) near
shore area off the Louisiana coast, and a 3) deepwater area off the
Louisiana coast. The 2004-2022 time series show a decreasing trend for
the urban (-0.027 DU/decade) and near shore (-0.0022 DU/decade) areas,
and an increasing trend (0.0019 DU/decade) for the deepwater area.
MERRA-2 wind and TROPOMI NO2 data were used to reveal several NO2
hotspots (up to 25% above background values) under calm wind conditions
near individual platforms. The NO2 signals from these deepwater
platforms and the high density of shallow water platforms closer to
shore were confirmed by TrC NO2 anomalies of up to 10%, taking into
account the monthly TrC NO2 climatology over the GOM. The results
presented in this study establish a baseline for future estimates of
emissions from the ONG hotspots and provide a methodology for analyzing
NO2 measurements from the new geostationary TEMPO instrument.