AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
An Evaluation of the Mixing and Evaporation of Organic Aerosol Components
CHRISTINE LOZA, Matthew Coggon, Jill Craven, Wilton Mui, Katherine Schilling, Rebecca Schwantes, Lindsay Yee, Xuan Zhang, Richard Flagan, John Seinfeld, Caltech
Abstract Number: 345 Working Group: Aerosol Chemistry
Abstract Ambient secondary organic aerosol (SOA) is a mixture of oxidation products of various anthropogenic and biogenic precursors. The nature of these mixtures and their phase behavior has been modeled theoretically using assumptions about gas-particle partitioning equilibrium and mixing ideality, but the some of these assumptions remain to be validated experimentally. We present results of experiments performed in the new Caltech dual 17-m$^3 chambers designed to probe the evaporation behavior of aerosol mixtures. SOA mixtures were formed from low-NO$_x oxidation of unlabeled alpha-pinene and labeled toluene under dry and humid conditions and were subjected to dilution and heating. A high-resolution time-of-flight aerosol mass spectrometer was used to separate the different aerosol types. A comparison of SOA mixing under dry and humid conditions and SOA evaporation behavior will be presented.