Models and Measurements for Investigating Atmospheric Transport and Photochemistry of Hg

EPA Grant Number: R829799
Title: Models and Measurements for Investigating Atmospheric Transport and Photochemistry of Hg
Investigators: Keeler, Gerald J. , Al-Wali, Khalid , Sillman, Sanford , Xu, Xiaohong
Current Investigators: Keeler, Gerald J. , Sillman, Sanford
Institution: University of Michigan
EPA Project Officer: Stelz, Bill
Project Period: November 1, 2002 through October 31, 2005 (Extended to October 31, 2006)
Project Amount: $899,597
RFA: Mercury: Transport, Transportation, and Fate in the Atmosphere (2001) RFA Text |  Recipients Lists
Research Category: Mercury , Air Quality and Air Toxics , Safer Chemicals , Air


The project will aim to develop a 3-d Eulerian model for transport and photochemistry of mercury, including fully integrated gas-phase, aqueous and aerosol chemistry. It also seeks to develop detailed comparisons between model results and measurements from two field campaigns: a recently completed field campaign in south Florida and campaigns currently being conducted for the Midwest. Model results will be used to investigate several research questions associated with mercury: the impact of local anthropogenic emissions relative to transport from distant sources (located more than 800 km away); the role of current anthropogenic emissions relative to re-volatilization from soils; the impact of photochemical processes on the atmospheric transport and transformation of mercury; and the relative importance of cloud processes and cloud chemistry of mercury in precipitating systems. A major objective will be to interpret measurements that might provide evidence on the above issues.


The Community Model for Air Quality (CMAQ) will be modified to include emissions, transport and chemistry of elemental and reactive mercury. The model currently includes 3-d transport and photochemistry of ozone, reactive nitrogen and aerosols. The CMAQ numerical solver for photochemistry will be extended to include fully integrated gas-phase and aqueous chemistry, including all relevant reactions for mercury. Updated atmospheric reaction rates for mercury will be incorporated into the model as they become available.

Model applications will be initially developed in association with the SAMPEX 2000 field campaign in southern Florida. A second series of model applications will be developed based on field measurements currently being conducted in Michigan and planned for the upper Midwest in 2003. Model evaluation and comparison with measurements will focus on a series of correlations between individual species: elemental versus reactive mercury; correlations among various forms of reactive mercury; and correlations between mercury and sulfate, reactive nitrogen, O3 and CO.

Expected Results:

Results include the development of a comprehensive 3-dimensional Eulerian model, including a version that will be made available to the regulatory community. It will provide the first model-based analysis of the impact of local emissions, transport, soil revolatilization and photochemistry on the deposition of mercury. Model-measurement comparisons will identify errors in the current understanding of atmospheric processes, transport, and chemistry of mercury. By identifying species that can be used to evaluate mercury transport and photochemistry, the project will also provide information useful for the development of future field campaigns.

Publications and Presentations:

Publications have been submitted on this project: View all 2 publications for this project

Supplemental Keywords:

photochemistry, modeling, eulerian model, mercury deposition, transport, environmental chemistry, RFA, Scientific Discipline, Air, INTERNATIONAL COOPERATION, Waste, Ecosystem Protection/Environmental Exposure & Risk, POLLUTANTS/TOXICS, Air Quality, air toxics, Environmental Chemistry, Chemicals, climate change, Air Pollution Effects, Fate & Transport, Environmental Monitoring, Chemistry and Materials Science, Atmospheric Sciences, Atmosphere, fate and transport, air pollutants, Hg, mercury, mercury emissions, modeling, mercury cycling, photochemistry, Eulerian model, chemical kinetics, atmospheric mercury chemistry, mercury chemistry, aerosol, atmospheric chemistry, atmospheric mercury cycling, atmospheric deposition, contaminant transport models, heavy metals, mercury vapor

Progress and Final Reports:

2003 Progress Report
2004 Progress Report
2005 Progress Report
Final Report