Atmospheric Aerosols from Biogenic Hydrocarbon OxidationEPA Grant Number: R831079
Title: Atmospheric Aerosols from Biogenic Hydrocarbon Oxidation
Investigators: Milford, Jana B. , Guenther, Alex , Helmig, Detlev , Wiedinmyer, Christine
Institution: University of Colorado at Boulder , National Center for Atmospheric Research
EPA Project Officer: Chung, Serena
Project Period: October 1, 2003 through September 30, 2006 (Extended to September 30, 2007)
Project Amount: $440,000
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
The main objective of the proposed research is to estimate contributions of biogenic volatile organic compounds (BVOC) to secondary aerosol production in the eastern United States. The proposed research focuses on contributions from oxidation of monoterpenes and sesquiterpenes (SQT) and seeks to understand the influence of environmental conditions, background oxidant concentrations and land management practices.
Temperature and light-dependent emission rates for a comprehensive suite of BVOC produced by dominant natural and agricultural vegetation will be incorporated into the Model of Exchange of Gases between the Atmosphere and Nature (MEGAN). To augment existing data for SQT, new data on SQT emissions and light and temperature dependencies will be acquired for critical vegetation species. Using MEGAN, BVOC emission inventories will be simulated for each of the four seasons. Summer inventories will also be developed for three hypothetical land management scenarios. The Community Multiscale Air Quality model (CMAQ; August 2003 version) will be modified to include gas-phase chemistry, secondary aerosol formation and gas-particle partitioning for MT and SQT. CMAQ results obtained using the base case BVOC inventories and existing anthropogenic emissions and meteorological inputs will be evaluated through comparison with aerosol data from the IMPROVE, SEARCH and PM Supersite networks. CMAQ will then be run with inventories for the alternative land management scenarios.
To date, SQT emissions have not been included in regional-scale studies of secondary aerosol formation in the U.S., but preliminary estimates suggest they may be highly significant. By including SQT and incorporating recent advances in biogenic emissions modeling methods, this study will provide improved estimates of BVOC emissions in the eastern U.S. The study will estimate regional landscape fluxes of MT and SQT and identify the primary vegetation species that contribute to secondary aerosol formation. By evaluating different land management scenarios, we will provide estimates of the change in BVOC emissions and air quality impacts based on land management practices. The understanding of BVOC emissions and their contribution to secondary aerosol formation provided by this study will allow for the determination of better pollution control strategies and improved prediction of the consequences of land management decisions.