Predominance of Combustion Aerosols at the Oliktok Point AMF3 Site in the Arctic

Description

With rapid Arctic sea ice loss, oil and gas extraction activities are increasing, yet little is known about their associated emissions. These particles have significant climate effects, including interacting with radiation, forming cloud droplets and ice crystals, and depositing onto surfaces. Given the complexity and evolving nature of atmospheric particles, as well as the challenges associated with Arctic measurements, significant uncertainties remain in our understanding of particle sources, evolution, and impacts in the Arctic. The ‘Summertime Aerosol across the North Slope of Alaska’ ARM field campaign was conducted by the University of Michigan and Baylor University at the AMF3 Oliktok Point field site during August-September 2016 to identify and quantify the sources, chemical composition, and mixing states of atmospheric particles. An aerosol time-of-flight mass spectrometer (ATOFMS) measure the size and chemical composition of 32,880 individual particles in real-time. Direct combustion plumes from local oil and gas extraction were characterized, with particles specific to diesel combustion and natural gas processing and combustion identified. Non-plume periods were characterized by aged combustion aerosol, with no period of clean Arctic air observed. Sea spray aerosol, aged by multiphase reactions involving emitted NOx and SO2, was observed throughout the study. These results inform how increasing Arctic development will impact Arctic atmospheric composition through local oil and gas extraction emissions.