AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Interactions of Glyoxal and SO2 in Clouds and Aqueous Aerosol: Production of SOA and Light-Absorbing Quinone Species
DAVID DE HAAN, Alyssa Andretta, Elyse Pennington, Hannah G. Welsh, Lelia Hawkins, Kevin Jansen, Margaret Tolbert, Mathieu Cazaunau, Edouard Pangui, Jean-François Doussin, University of San Diego
Abstract Number: 132 Working Group: There Must be Something in the Water: Cloud, Fog and Aerosol Aqueous Chemistry for Aerosol Production
Abstract Field studies have shown that aerosol oxalate and sulfate are highly correlated. This correlation has been attributed to the fact that both ions are formed mainly via oxidation of precursor species glyoxal and SO2 in cloudwater. Glyoxal and SO2 react with each other in the aqueous phase, however, forming adduct species that can be oxidized and oligomerized into hydroxyquinone products. Hydroxyquinones are redox-active and strongly light absorbing, and thus their atmospheric formation could be relevant to both human health and climate change. Bulk aqueous studies of glyoxal + SO2 chemistry have shown that hydroxyquinone products are rapidly formed at liquid surfaces at high pH, and these reaction mixtures turn brown at pH levels as low as 5. For these reasons, a series of SOA formation experiments were conducted with glyoxal and SO2 in a cloud / smog chamber. Aerosol optical properties were monitored with cavity attenuated phase shift single-scattering albedo (CAPS-ssa) spectroscopy at 450 nm and PILS / waveguide UV-vis spectroscopy. Gas phase species were monitored by high-resolution PTR-MS and long-path FTIR, while aerosol-phase species were identified by high-resolution LCMS analysis of filter extracts. This dataset is utilized to describe the multi-phase reactivity of glyoxal – SO2 reaction products.