AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Modeling Nanoparticle Growth in Biogenic VOC+Nitrate Radical Chamber Studies
KELLEY C. BARSANTI, Juliane L. Fry, Danielle C Draper, John Ortega, Steven Brown, Peter Edwards, Michael J. Lawler, Paul M Winkler, Peter McMurry, James N. Smith, Portland State University
Abstract Number: 438 Working Group: Aerosol Chemistry
Abstract New particle formation (NPF) in the atmosphere may contribute to the formation of cloud condensation nuclei if the newly formed particles grow faster than they are scavenged. Research over the last twenty years has shown that relatively rapid growth of nanometer-sized particles (> 2-3 nm) cannot be explained by condensation of sulfuric acid alone and that organic compounds clearly play a role. It has been suggested that relatively volatile/low molecular weight compounds may contribute to NPF via organic salt and/or accretion product formation; relatively non-volatile/high molecular weight compounds may condense directly to contribute to NPF. Much work is currently being done to elucidate the key mechanisms by which organic compounds contribute to NPF, and to identify the critical species involved. Parallel efforts are underway to represent such processes in models capable of predicting NPF in laboratory studies as well as in the atmosphere. In this work, process-level modeling was used to evaluate particle growth in chamber experiments of individual monoterpenes with nitrate radical. Comparisons of measured and modeled growth rates and secondary organic aerosol yields were used to describe the limitations in available biogenic volatile organic compound (VOC)+nitrate radical parameterizations and to explore the potential species, including organonitrates, contributing to NPF in these chamber experiments.