AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Development of an Air Quality Model for Particle Formation from Sulfur Compounds and Amines
ANDREW MARTINEZ, Matt Dawson, Veronique Perraud, Barbara J. Finlayson-Pitts, Donald Dabdub, University of California, Irvine
Abstract Number: 609 Working Group: Urban Aerosols
Abstract Airborne particles are known for their wide-ranging effects on human health and climate, including their influence on cloud formation and ground-level solar radiation. The mechanisms and dynamic responses of particle formation are not well understood, contributing to International Panel of Climate Change’s conclusion that this class of species provides the largest uncertainty in estimating the overall effect on radiative forcing and climate change. In particular, it has been shown that conventional air quality models cannot match observed atmospheric concentrations of airborne particles, particularly secondary organic aerosol (SOA) formed from oxidation of organic precursors. Discrepancies of a factor of ten or more have been reported. Recent experimental work has sought to provide greater accuracy to models’ predictive capability via the identification of previously unrecognized reaction mechanisms. In this regard, the authors’ efforts have focused primarily on the system consisting of combinations of amines, organosulfur compounds, sulfuric acid, and methanesulfonic acid. The authors are integrating reaction mechanisms for particle formation from these precursors into the previous-generation UCI-CIT air quality model. This three-dimensional, spatially resolved model is then utilized to investigate the potential for particle formation via these newly-included mechanisms. Of particular importance are the development of amine emission scenarios and investigation of oxidation chemistry that would compete with particle formation (via species such as OH and ozone). These considerations have been utilized as a tool for assessing the overall potential for particle formation from these reaction pathways in the South Coast Air Basin of California.