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Abstract Oil and gas production regions are significant sources of greenhouse gases and reactive pollutants such as nitrogen oxides (NO_x) and volatile organic compounds. Research has also shown that methane (CH₄) emissions reported to the Environmental Protection Agency's (EPA) Greenhouse Gas Reporting Program (GHGRP) are generally underestimated. The Arctic accounted for 5.5% of global oil and gas production in 2022 but is estimated to contain significant undiscovered resources. The emitted NO_xand volatile organic compounds can impact the composition and chemistry of the Arctic atmosphere. The Prudhoe Bay Oil Field in Alaska is one of the 10 largest oil fields in the US and has been approved for significant development expansion. However, only one recent study has reported measurements of its greenhouse gas emissions. We estimate the emission rates for carbon dioxide (CO₂), CH₄, and NO_xfrom the Prudhoe Bay Oil Field during the spring of 2022 using airborne mass balance methods and emission ratios. We also discuss emissions per energy produced and show an increase over time, with values higher than the national average for oil and gas producing regions, though within uncertainties. Our estimates are lower than the NO_xemission estimate reported in the National Emissions Inventory (NEI), as seen in other oil and gas studies, but fall within the uncertainty range of the greenhouse gases reported in the GHGRP. This work provides a valuable snapshot of emissions before further expansion of extraction activities. 

Abstract The Chemistry in the Arctic: Clouds, Halogens, and Aerosols (CHACHA) field project aimed to advance the understanding of coupled meteorological and chemical processes in the atmospheric boundary layer during the seasonal increase in sea ice fracturing in spring. CHACHA sought to understand the interactions between this changing snow-covered surface, surface-coupled clouds, sea spray aerosols, multiphase halogen chemistry, and impacts of emissions from oil and gas extraction on atmospheric chemistry. The project measured greenhouse gases, reactive gases, size-resolved aerosol number concentrations, cloud microphysical properties, and meteorological conditions in real time, while also collecting particles for offline analysis. Two instrumented aircraft were deployed: the Purdue University Airborne Laboratory for Atmospheric Research and the University of Wyoming King Air. Flights were conducted out of Utqiaġvik, Alaska, between 21 February and 16 April 2022, sampling air over snow-covered and newly frozen sea ice in the Beaufort and Chukchi Seas, over open leads, and over the snow-covered tundra of the North Slope of Alaska, including the oil and gas extraction region near Prudhoe Bay. Observations showed that reactive bromine gases generally peaked near the snow-covered surface and decayed rapidly within the lowest few hundred meters where ozone was depleted, with concentrations reduced by nitrogen oxides emitted from oil fields. Cloud microphysical measurements revealed that thin clouds over and downwind of leads grew in vertical extent after contact with open water. Results from dropsondes indicated that convective boundary layers developed over leads, with depths ranging from 250 to 850 m depending on the fetch.