Two Air Quality Regimes in Total Column NO₂ Over the Gulf of Mexico in May 2019: Shipboard and Satellite Views

Abstract

The Satellite Coastal and Oceanic Atmospheric Pollution Experiment (SCOAPE) cruise in the Gulf of Mexico was conducted in May 2019 by NASA and the Bureau of Ocean Energy Management to determine the feasibility of using satellite data to measure air quality in a region of concentrated oil and natural gas (ONG) operations. SCOAPE addressed both technological and scientific issues related to measuring NO2 columns over the outer continental shelf. Featured were nitrogen dioxide (NO2) instruments (Pandora, Teledyne API analyzer) at Cocodrie, LA (29.26°, −90.66°), and on the Research Vessel Point Sur operating off the Louisiana coast with measurements of ozone, carbon monoxide, and volatile organic compounds (VOCs). The findings: (a) all NO2 observations revealed two atmospheric regimes over the Gulf, the first influenced by tropical air in 10–14 May, the second influenced by flow from urban areas on 15–17 May; (b) comparisons of OMI v4 and TROPOMI v1.3 TC (total column) NO2 data with shipboard Pandora NO2 column observations averaged 13% agreement with the largest difference during 15–17 May (∼20%). At Cocodrie, the satellite–Pandora agreement was ∼5%. (c) Three new‐model Pandora instruments displayed a TC NO2 precision of 0.01 Dobson Units (∼5%); (d) regions of smaller, older natural gas operations showed high methane readings from leakage; elevated VOCs were also detected. Neither satellite nor spectrometer captured the magnitude of ambient NO2 variability near ONG platforms. Given an absence of regular air quality monitoring over the Gulf of Mexico, SCOAPE data constitute a baseline against which future observations can be compared.

Surf, Turf, and Above the Earth: Unmet Needs for Coastal Air Quality Science in the Planetary Boundary Layer (PBL)

“…Understanding these non‐traditional emission sources will require the combination of satellite estimates and evaluations from sub‐orbital campaign data sets. Preliminary studies reaching similar conclusions were documented in the Chesapeake Bay region (Caicedo et al., 2021; Gronoff et al., 2019; Ring et al., 2018), the South Korean coast waters (Thompson et al., 2019; Tzortziou et al., 2018), the Gulf of Mexico (Thompson et al., 2023), the Lake Michigan region (Vermeuel et al., 2019) and along the New York City coast (Nauth et al., 2023; Tzortziou et al., 2022). Identify novel and viable pathways derived from the interaction of the land‐ocean‐atmosphere that can drive PBL content and structure in coastal communities.…”

“…Satellite measurements of tropospheric and total column amounts of nitrogen dioxide (NO 2 , Figure 2) have become increasingly accurate over the past two decades with improvements to retrieval algorithms from instruments like the GOME (Global Ozone Monitoring Experiment) series, Ozone Monitoring Instrument (OMI) and the higher spatial resolution TROPOspheric Monitoring Instrument (TROPOMI). However, relating the column amounts of pollutants to “nose‐level” or PBL concentrations, especially in coastal regions, remains a challenge due to the complexities of vertical distribution and often strong spatial and temporal variability in surface (land or ocean) reflectivity (Knepp et al., 2015; Kollonige et al., 2018; Szykman et al., 2019; Thompson et al., 2019, 2023; Tzortziou et al., 2015, 2018). However, continued work is moving toward evaluating and utilizing these satellite derived NO 2 products to the neighborhood scale (Demetillo et al., 2021; Dressel et al., 2022; Goldberg et al., 2021; Johnson et al., 2022; Judd et al., 2020) to better evaluate urban pollution and human health (Anenberg et al., 2022).…”

Satellite NO2 Trends and Hotspots Over Offshore Oil and Gas Operations in the Gulf of Mexico

“…Since meteorological regimes drove much of the variability in TC NO 2 in coastal areas during SCOAPE‐I (Thompson et al., 2023), we also analyzed how the time series differ according to different wind speed and directions (source regions). For this objective, daily MERRA‐2 wind data from 2005 to 2022 were used to restrict the NO 2 averaging to days based on three cases: (a) Wind from the north (land) at greater than 10 ms −1 (b) wind from the south (GOM) at greater than 10 ms −1 , and (c) calm winds of less than 5 ms −1 .…”

“…Preliminary results were summarized in two documents by Duncan (2020) and Thompson et al (2020). These were followed by detailed reports on a 2019 field campaign (Satellite Coastal and Oceanic Atmospheric Pollution Experiment), SCOAPE-I (Thompson et al, 2020(Thompson et al, , 2023, along the Louisiana coast.…”

“…(2020). These were followed by detailed reports on a 2019 field campaign (Satellite Coastal and Oceanic Atmospheric Pollution Experiment), SCOAPE‐I (Thompson et al., 2020, 2023), along the Louisiana coast.…”