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COMMUNITY SCALE AIR TOXICS MODELING WITH CMAQ
Citation:
Ching, J.K S., J Herwehe, S. Dupont, AND R. Tang. COMMUNITY SCALE AIR TOXICS MODELING WITH CMAQ. Presented at 3 CMAS Workshop, Research Triangle Park, NC, October 27-29, 2003.
Impact/Purpose:
The objective of this task is to develop and evaluate numerical and physical modeling tools for simulating ground-level concentrations of airborne substances in urban settings at spatial scales ranging from ~1-10 km. These tools will support client needs in the areas of air toxics and homeland security. The air toxics tools will benefit the National Air Toxics Assessment (NATA) program and human exposure modeling needs within EPA. The homeland security-related portion of this task will help in developing tools to assess the threat posed by the release of airborne agents. Both sets of tools will consider the effects induced by urban morphology on fine-scale concentration distributions.
Description:
Consideration and movement for an urban air toxics control strategy is toward a community, exposure and risk-based modeling approach, with emphasis on assessments of areas that experience high air toxic concentration levels, the so-called "hot spots". This strategy will require information that accurately maps and characterizes the spatial and temporal variability of such pollutants. Many air toxic pollutants are active in photochemistry and ambient concentration levels will, therefore, depend on both the magnitude of the secondary products from the inflow regional background as well as from fresh emissions. In principle, the Community Multi-scale Air Quality (CMAQ) modeling system, using multi-scale modeling attributes can provide the ambient concentrations of air toxics from both regional and local sources and through advanced treatment of chemical, transport and deposition pathways. This paper explores the CMAQ capability to model air toxics at fine scale to meet the desired air toxics assessments objectives.
This paper has been reviewed in accordance with United States Environmental Protection Agency's peer and administrative review policies and approved for presentation and publication.