Arctic Ocean and Prudhoe Bay Influences on Atmospheric Particle Chemical Mixing States on the North Slope of Alaska

Description

Unprecedented summertime Arctic sea ice loss is opening the region to increased oil and gas extraction activities and ship traffic. Arctic aerosol emissions are expected to increase with increasing anthropogenic activities and production of sea spray aerosol. 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. An ARM field campaign was conducted by the University of Michigan and Baylor University in Barrow, Alaska during August-September 2015 to characterize the chemical composition and mixing states of atmospheric particles. An aerosol time-of-flight mass spectrometer (ATOFMS) and computer-controlled scanning electron microscopy with energy dispersive X-ray (CCSEM-EDX) analysis were utilized to measure the size and chemical composition of individual particles. Additionally, organic carbon, elemental carbon, black carbon, and inorganic ion concentrations, as well as size-resolved particle number concentrations, were measured to provide a full suite of atmospheric aerosol chemical composition data. Aerosol particle mixing state was observed to vary between Arctic Ocean and Prudhoe Bay influence, with significant secondary processing observed for the particles with air masses traveling from Prudhoe Bay, the largest oilfield in North America.