AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Fog Processing of Particulate Molecular Marker Species
Jershon Eagar, Franz Ehrenhauser, Youliang Wang, James Hutchings, Aurelie Marcotte, Olivier Delhomme, Raghava Kommalapati, Mary Wornat, Kalliat Valsaraj, PIERRE HERCKES, Arizona State University
Abstract Number: 595 Working Group: Urban Aerosols
Abstract Fog and cloud processing of carbonaceous aerosol material can impact atmospheric concentrations of molecular species through scavenging, aqueous phase reactivity and/and depositional processes. In 2 recent field studies in Fresno (CA) and Davis (CA) the processing of organic species in particular so called molecular marker species, used in source apportionment studies was investigated. Pre- and post fog as well as interstitial aerosol samples were analyzed as well as the aqueous phase (fog) composition. Laboratory studies were conducted to investigate the reactivity of select species in the aqueous phase and identify reaction products and rate under common fog conditions.
Observational results show a differential scavenging of molecular marker species, suggesting selective scavenging of aerosols of some sources over of aerosols from different sources. The results and implications on atmospheric lifetimes will be discussed in detail. A relationship between scavenging efficiency and fog liquid water content, as suggested by earlier studies, could not be confirmed.
Laboratory studies on chrysene reactivity in fog conditions show a surprising diversity of reaction products and the results will be discussed relative to the field observations of the oxygenated daughter species.