AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Characterization of the Heterogeneous Aging of Secondary Organic Aerosols Formed via Isoprene Ozonolysis Using Aerosol Flow Tube - FTIR Spectroscopy
Demetrios Pagonis, Brian Bouchard, Jeff Baker, CINDY DEFOREST HAUSER, Davidson College
Abstract Number: 305 Working Group: Aerosol Chemistry
Abstract Isoprene is emitted by plants at a rate of 600 Tg yr-1, and is the second most abundant organic compound in the atmosphere, behind methane. When isoprene reacts with ozone, the oxidation products are less volatile and condense to form secondary organic aerosols (SOA). This is of particular concern in areas such as the southeastern United States, where there has been significant kudzu invasion. Kudzu is a strong emitter of both isoprene and ozone-forming compounds, creating an environment ripe for the production of SOA. These aerosols and their precursors undergo additional reactions after formation called heterogeneous aging. In these studies, we use a relative rates approach to study the heterogeneous aging of SOA generated through isoprene ozonolysis. The formation and aging processes are decoupled in space and time through the combination of a chamber, denuder and aerosol flow tube. The composition, concentration, particle size and number density of the aged aerosol is characterized using Fourier Transform Infrared Spectroscopy (FTIR) and a Scanning Mobility Particle Sizer (SMPS), allowing us to develop a kinetic model for the heterogeneous aging of isoprene SOA.