Plume-in-Grid Modeling of the Atmospheric Deposition of Mercury over the United States

Krish Vijayaraghavan, Prakash Karamchandani, Rochelle Balmori, Christian Seigneur
Atmospheric & Environmental Research, Inc. (AER), 2682 Bishop Drive, Suite 120, San Ramon, CA

Leonard Levin
EPRI, 3412 Hillview Avenue, Palo Alto, CA 94304

John J. Jansen
Southern Company Services, P.O. Box 2641, Birmingham, AL 35291


CMAQ-MADRID-APT (the Community Multiscale Air Quality model coupled with new particulate matter (PM) and mercury modules and advanced plume treatment) is a multi-pollutant model which offers sophisticated treatments of ozone, PM and mercury processes. The model has been further enhanced with a state-of-the-science analysis of the atmospheric dynamics and chemistry of mercury in plumes from elevated point sources. This paper presents the application of this plumein- grid model to simulate the wet and dry deposition of mercury species over the United States during 2001. Meteorology is driven by the Mesoscale Model version 5 (MM5). Emissions of criteria pollutants and mercury over the United States were obtained from the U.S. EPA and are based on the National Emission Inventory (NEI) for 1999 with additional corrections made by EPA for MACT controls of mercury emissions from some waste incinerators. CMAQ-MADRID-APT is applied here over a domain that covers the continental United States and parts of Canada and Mexico and has a horizontal resolution of 36 km with 14 vertical levels extending up to the tropopause. Model performance is evaluated by comparison of simulated wet deposition of mercury with 2001 wet deposition data from the Mercury Deposition Network (MDN) in the National Atmospheric Deposition Program (NADP). The impact of using an explicit treatment of the plumes from thirty large coal-fired power plants in the United States on local and regional mercury deposition is investigated.