Fundamental Experimental and Modeling Studies of Secondary Organic AerosolEPA Grant Number: R831075
Title: Fundamental Experimental and Modeling Studies of Secondary Organic Aerosol
Investigators: Seinfeld, John , Clegg, Simon , Flagan, Richard
Current Investigators: Seinfeld, John
Institution: California Institute of Technology , University of East Anglia
Current Institution: California Institute of Technology
EPA Project Officer: Chung, Serena
Project Period: July 1, 2003 through June 30, 2006
Project Amount: $449,991
RFA: Measurement, Modeling, and Analysis Methods for Airborne Carbonaceous Fine Particulate Matter (PM2.5) (2003) RFA Text | Recipients Lists
Research Category: Air , Air Quality and Air Toxics , Particulate Matter
Understanding the sources, molecular composition, and chemistry of formation of atmospheric secondary organic aerosol represents a key problem in atmospheric chemistry. Secondary organic aerosol arises when volatile organic compounds (VOCs) are oxidized in the atmosphere to form products that have sufficiently low volatility to partition between the gas and particulate phases. These products tend to be highly oxidized, polar organic molecules containing six or more carbon atoms. The partitioning is determined by the dissolution of the low-vapor pressure organics into a particulate phase that consists in general of a mixture of already condensed organic compounds, primary carbonaceous material, water, and dissolved inorganic electrolytes. Laboratory measurements of the overall mass yields of aerosol from oxidation of individual VOCs provide the fundamental data to test first-principles prediction of aerosol formation. The objective of this study is to improve the ability of source-oriented atmospheric models to simulate the formation of secondary organic aerosol (SOA).
The proposed approach includes three major aspects: (1) a comprehensive program of laboratory chamber experiments on SOA formation; (2) continued development of theoretical models of SOA formation that can be included in atmospheric models; and (3) evaluation of the models against the laboratory chamber data.
One expected result of the research will be an organic aerosol module suitable for incorporation in airshed models.