Exploring the Heterogeneous Ozonolysis Reactions of Secondary Organic Aerosols using AFT-FTIR

CINDY DEFOREST HAUSER (1), Justin Godinho (1)

(1) Davidson College

     Abstract Number: 571
     Last modified: May 13, 2010

Abstract
Heterogeneous chemical reactions are a critical component in the ageing processes of atmospheric aerosols. Since a large fraction of atmospheric aerosols are generated as secondary organic aerosols, an increased understanding of the ageing of this class of aerosols will be valuable in interpreting atmospheric aerosol measurements and accurately presenting these processes in climate models. In the studies presented here, the formation of secondary organic aerosols from limonene and nitrate, a nighttime formation pathway, is decoupled from the daytime ageing process or heterogeneous chemical reaction of the SOA with ozone in an aerosol flow tube. Using FTIR, we characterize the aerosol before and after reaction with ozone. By reacting the SOA with ozone in the flow tube, we can change the ozone concentration or reaction time to probe the kinetics of the ozonolysis reaction.