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SENSITIVITY ANALYSIS OF THE MULTI-LAYER MODEL USED IN THE CLEAN AIR STATUS AND TRENDS NETWORK (CASTNET)
Citation:
Lavery, T., C. Rogers, K. Mishoe, AND R. E. BAUMGARDNER. SENSITIVITY ANALYSIS OF THE MULTI-LAYER MODEL USED IN THE CLEAN AIR STATUS AND TRENDS NETWORK (CASTNET). U.S. Environmental Protection Agency, Washington, D.C., EPA/600/R-08/126, 2008.
Impact/Purpose:
Healthy Communities and Ecosystems - by providing new approaches to characterize landscape features, conditions, and change.
Description:
The U.S. Environmental Protection Agency (EPA) established the Clean Air Status and Trends Network (CASTNET) and its predecessor, the National Dry Deposition Network (NDDN), as national air quality and meteorological monitoring networks. The purpose of CASTNET is to track the progress of the 1990 Clean Air Act Amendments (CAAA) emission reduction program for sulfur dioxide (SO2) and oxides of nitrogen (NOx) in terms of reductions in sulfur and nitrogen deposition, improved air quality, and changes to affected ecosystems. Both CASTNET and NDDN were designed to measure concentrations of sulfur and nitrogen gases and particles and to estimate dry deposition using an inferential model. The design was based on the concept that atmospheric dry deposition flux could be estimated as Flux = C*Vd, where C represents a measured air pollutant concentration and Vd represents a modeled deposition velocity. In other words, the flux is directly proportional to the deposition velocity. Consequently, an uncertainty in the deposition velocity produces an uncertainly in the flux estimate.