Impacts of Emissions of C₂‐C₅ Alkanes From the U.S. Oil and Gas Sector on Ozone and Other Secondary Species

Abstract

Inside many U.S. oil and gas-producing regions, the oil and gas sector dominates local anthropogenic emission fluxes of C 2-C 5 alkanes. Here, we present a detailed analysis of the impact of these emissions on secondary species production over the continental United States using the GEOS-Chem model. Oil-and gas-producing areas in the central United States show the highest summertime surface ozone (O 3) enhancements due to oil and gas C 2-C 5 alkane emissions. The Colorado Front Range is the most impacted 8-hr O 3 non-attainment area in the United States with 3-hr daytime instantaneous O 3 enhancements >4 ppb. From three selected non-attainment areas, the Colorado Front Range has (1) the lowest monthly mean VOC reactivity (1.5 s −1); (2) the highest percent contribution of oil and gas sources (52%) to calculated VOC reactivity; and (3) the largest relative increases in PAN (peroxyacetyl nitrate), PPN (peroxypropionyl nitrate), and >C 4 alkyl nitrates. Enhanced abundances of PAN, PPN, and >C 4 alkyl nitrates have the potential to perturb remote O 3 production through increased NO x export to remote regions via PAN chemistry. Globally, simulated C 2-C 5 alkane emissions from the U.S. oil and gas sector contribute 0.5 Tg (~0.17%) to the tropospheric O 3 burden with a~0.27% contribution in the Northern Hemisphere.

Summertime Ozone Production at Carlsbad Caverns National Park, New Mexico: Influence of Oil and Natural Gas Development

“…However, certain regions, particularly in the western and central US, have seen more modest declines or even increasing O 3 trends (Strode et al., 2015; US EPA, 2023). Sources of O 3 precursors that have gained prominence or recognition in recent years include enhanced wildfire activity (Jaffe et al., 2022), volatile chemical product emissions (Coggon et al., 2021; Seltzer et al., 2022), and the oil and natural gas (O&G) industry (Allen, 2016; Pozzer et al., 2020; Tzompa‐Sosa & Fischer, 2021).…”