HR: 0800h
AN: A31A-0818    [Abstracts]
TI: Contribution of the Pacific Coast Area to Particulate Sulfate in the Western United States Based on Trajectory Regression Analysis
AU: * Xu, J
EM: jin.xu@dri.edu
AF: Desert Research Institute, 755 E. Flamingo Road, Las Vegas, NV 89119 United States
AU: DuBois, D
EM: Dave.DuBois@dri.edu
AF: Desert Research Institute, 755 E. Flamingo Road, Las Vegas, NV 89119 United States
AU: Pitchford, M
EM: Marc.Pitchford@noaa.gov
AF: NOAA Air Resource Laboratory, 755 E. Flamingo Road, Las Vegas, NV 89119 United States
AU: Green, M
EM: Mark.Green@dri.edu
AF: Desert Research Institute, 755 E. Flamingo Road, Las Vegas, NV 89119 United States
AU: Etyemezian, V
EM: Vic.Etyemezian@dri.edu
AF: Desert Research Institute, 755 E. Flamingo Road, Las Vegas, NV 89119 United States
AB: Atmospheric aerosols can significantly reduce visibility and result in regional haze. The Clean Air Act amendments established a national visibility goal to remedy existing impairment and prevent future impairment in Federal Class I areas (national parks and wilderness areas designated by Congress), most of which are in the western U.S. In order to identify the major source regions of the atmospheric aerosols in the Class I areas of the western United States, backtrajectories are calculated for each Western Regional Air Partnership (WRAP) Class I area every three hours at three starting heights (10, 500, 1500m) for the years 2000-2002 using the NOAA HYSPLIT v4.6 model. Under the concept that the amount of time air spends over a region determines that region's contribution to the sulfate concentration measured at the receptor site, multiple-linear regression between the Interagency Monitoring of Protected Visual Environments (IMPROVE) measured sulfate concentration and the residence time in the pre-defined potential source regions was conducted for each Class I area. The results suggest that sulfate aerosol can be transported over long distances and impact large areas. Shipping and other port emissions from the Pacific Coast area are estimated to have significant contributions to atmospheric sulfate aerosol concentrations in large areas of the western United States. On average, 11 to 15 percent of the sulfate is attributed to the Pacific Coast area for all WRAP continental IMPROVE sites studied. The Pacific Coast area contributes about 50 percent to ambient sulfate for the major port areas of southern California based on the regression. These analyses suggest that shipping / port emissions need to be considered in the development of efficient control strategies for reducing the concentrations of sulfate and other aerosol species.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0341 Middle atmosphere: constituent transport and chemistry (3334)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005