Citation:

Liu, Y., R. Park, Q. Li, V Kilaru, J. Sarnat, AND D. J. Jacobs. MAPPING ANNUAL MEAN GROUND-LEVEL PM2.5 CONCENTRATIONS USING MULTIANGLE IMAGING SPECTRORADIOMETER AEROSOL OPTICAL THICKNESS OVER THE CONTIGUOUS UNITED STATES. JOURNAL OF GEOPHYSICAL RESEARCH. American Geophysical Union, Washington, DC, 109:D22206,doi:10.1029/2, (2004).

Impact/Purpose:

Our main objective is to assess the exposure of selected ecosystems to specific atmospheric stressors. More precisely, we will analyze and interpret environmental quality (primarily atmospheric) data to document observable changes in environmental stressors that may be associated with legislatively-mandated emissions reductions.

Description:

We present a simple approach to estimating ground-level fine particle (PM2.5, particles smaller than 2.5 um in diameter) concentration using global atmospheric chemistry models and aerosol optical thickness (AOT) measurements from the Multi- angle Imaging SpectroRadiometer (MISR). The method uses seasonally averaged data in 2001 for the United States and compares the results with EPA PM2.5 ground-level observations, Overall, the estimated PM2.5 concentrations are within 20% of EPA observations. In addition, estimated PM2.5 concentrations capture the spatial and seasonal patterns slightly better than the surface level PM2.5 concentration predicted using the GEOS-CHEM model alone. The estimated PM2.5 concentrations also showed the potential to be less influenced by AOT prediction biases in GEOS-CHEM or the Georgia Tech/Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model since MISR AOT is able to bring in more urban scale variation of particulate matter pollution. With the rapid development of model capabilities, we expect the weak correlation between model AOT and MISR AOT measurements to be improved significantly in the future and estimated PM2.5 concentrations by this simple approach will be more comparable with observations.

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