AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
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Photolysis of Aqueous Atmospheric Aerosol Mimics
MELISSA GALLOWAY, Jacqueline Sharp, Shiqing Ma, Joseph Woo, Lafayette College
Abstract Number: 861 Working Group: Aerosol Chemistry
Abstract Aqueous reactions of small, water soluble aldehydes with amines or ammonium salts have been shown to be important for atmospheric brown carbon formation processes. The extent to which photolysis of these brown carbon compounds changes the chemical composition and light absorption of these systems is not well understood or characterized. We photolyze aged reaction systems of aqueous carbonyls (e.g., glycolaldehyde, glyoxal, methylglyoxal, and hydroxyacetone) and ammonium sulfate and monitor light absorption and chemical composition via UV-visible spectroscopy and mass spectrometry. Photobleaching and photobrowning rates vary with wavelength and aldehyde identity, while mass spectrometry shows that the chemical composition changes significantly upon photolysis.