Observations of ozone, acyl peroxy nitrates, and their precursors during summer 2019 at Carlsbad Caverns National Park, New Mexico

In Situ Sampling of NOx Emissions from United States Natural Gas Flares Reveals Heavy-Tail Emission Characteristic

“…Studies have shown that oil and gas emissions have degraded air quality in surrounding regions through increases in ozone concentrations, at times resulting in exceedances of EPA National Ambient Air Quality Standards (NAAQS). − Pozzer et al found that oil and gas emissions contributed to increased ozone in 90% of the contiguous U.S., with the highest summer enhancements seen in the central U.S., coincident with areas in nonattainment with ozone NAAQS . NOx is an important precursor of tropospheric ozone; however, the efficiency of its generation varies depending on other conditions (e.g., VOC/NOx ratio, solar radiance).…”

“…NOx is an important precursor of tropospheric ozone; however, the efficiency of its generation varies depending on other conditions (e.g., VOC/NOx ratio, solar radiance). In NOx-limited regions, such as Carlsbad Caverns National Park, NAAQS exceedances have been attributed to emissions, particularly NOx, from the nearby Permian basin . In addition to the contribution to ozone generation, NOx also has a direct impact on air quality. , Buonocore et al found that 2016 oil and gas emissions resulted in considerable health impacts (e.g., 410,000 asthma exacerbations), with NO 2 as the highest contributor to those adverse outcomes compared to ozone and PM2.5.…”

Source characterization of volatile organic compounds at Carlsbad Caverns National Park

“…During periods with S-SE winds, contributions of the three O&G factors increased. The two secondary factors also contributed significantly to the measured VOCs, especially during periods when O 3 was high, whereas contributions of the three O&G factors decreased during high O 3 events compared to other periods with S-SE winds, especially the process-specific O&G factor 3 (Pollack et al 2023).…”

“…Light alkenes have been linked to vehicular emissions in urban areas and O&G production regions (Baker et al 2008;Swarthout et al 2013) but also can be emitted by industrial activities (Washenfelder et al 2010), vegetation (Rhew et al 2017), and biomass burning (Akagi et al 2012;Hecobian et al 2011). CAVE was not significantly impacted by wildfire plumes in 2019 during CarCavAQS (Pollack et al 2023). Since CAVE is more than 140 km away from major urban centers and high contributions of the alkene factor occurred mostly with S-SE winds, we hypothesize that the alkene factor may reflect influence from vehicular or other combustion emissions associated with O&G activities in the Permian Basin.…”

“…The campaign was designed to investigate the impacts of regional sources on fine particle formation (PM 2.5 ), VOC composition, O 3 and PAN formation, and nitrogen deposition. The composition, sources, and visibility impacts of PM 2.5 at CAVE have been discussed in Naimie et al (2022), while O 3 , NO x , and PAN observations are discussed in Pollack et al (2023). In this work, we characterize sources of VOCs at CAVE using positive matrix factorization (PMF) analysis and consider the contribution of different sources to VOC reactivity.…”