Single-Particle Chemical Composition in the Arctic during the Winter-Spring Transition

Monday, 14 December 2015
Poster Hall (Moscone South)
Kerri Pratt1, Rachel Kirpes2, Amy L Bondy2, Alexander Laskin3, Bingbing Wang3 and Andrew P Ault2, (1)University of Michigan Ann Arbor, Department of Chemistry and Department of Earth & Environmental Sciences, Ann Arbor, MI, United States, (2)University of Michigan, Ann Arbor, MI, United States, (3)Pacific Northwest National Laboratory, Richland, WA, United States
Atmospheric particles have significant, but highly uncertain, impacts on the Arctic climate by decreasing snow/ice albedo, scattering/absorbing solar radiation, nucleating cloud droplets and ice crystals, and contributing to atmospheric trace gas budgets. In the winter, atmospheric particles and trace gases are transported from the mid-latitudes to the Arctic, forming a springtime ‘Arctic haze’. In the winter-spring, thinning sea ice is causing ice fracturing and the formation of open sea ice leads, which are suggested to be a source of local sea spray aerosol. To investigate the chemical composition and source of atmospheric aerosols during the winter-spring transition in the Arctic, 0.1-5 µm particles were collected during January and February 2014 near Barrow, Alaska. The elemental composition and morphology of these particles were examined using computer-controlled scanning electron microscopy with energy dispersive X-ray spectroscopy (CCSEM-EDX). Significantly, major contributions of sea spray aerosol were observed for both submicron and supermicron size ranges during a nearby open lead event, and organic-sulfate (‘Arctic haze’) particles were also abundant at <1 µm in diameter. The single-particle chemical composition, sources, and evidence of aging processes will be discussed.