You are here:
MODELING REGIONAL-SCALE ATMOSPHERIC MERCURY USING RELMAP
Citation:
Bullock, O., W. Benjey, AND M. Keating. MODELING REGIONAL-SCALE ATMOSPHERIC MERCURY USING RELMAP. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/A-95/115 (NTIS PB96114566), 1995.
Description:
The Regional Lagrangian Model of Air Pollution (RELMAP) is used to simulate the emission, transport and diffusion, chemical transformation, and wet and dry deposition of elemental mercury gas, divalent mercury gas and particulate mercury. ased on recent modeling advances in Europe, the RELMAP has been modified to simulate a reduction-oxidation (redox) balance for mercury dissolved in cloud and rain water. his redox balance is used in the estimation of a variable precipitation scavenging ratio for elemental mercury. et removal of divalent mercury gas and particulate mercury is modeled using constant wet scavenging ratios. ry deposition is estimated using deposition velocities developed from various modeling studies in the U.S. and in Europe. A mercury air emission inventory for the continental United States is used to estimate the releases of elemental mercury gas, divalent mercury gas and particulate mercury based on emission speciation estimates for the various emitter types in the inventory. verage annual concentrations and wet and dry deposition totals for these three forms of mercury have been simulated. he results of the simulation are used to estimate the quantity of mercury emitted to the air annually over the United States and the amount that is subsequently deposited back to U.S. soils and water bodies. An analysis of the modeling results also provides some information about the areas of the country thought to have the most significant exposure from all air emissions of mercury. his analysis contributes to the understanding of the key variables, such as source location, chemical and physical form of emission, or meteorology, that lead to these outcomes.
