Air Quality Management Online Portal
Air Quality Modeling
Air Quality modeling is the mathematical prediction of ambient concentrations of air pollution, based on measured inputs.
Air quality modeling is the necessary substitute for ubiquitous air quality monitoring, which is impossible. Air quality managers can use models to predict the impacts from a potential emitter, which is useful for permitting new sources. Managers can also apply models for the simulation of ambient pollution concentrations under different policy options, as a tool to both make and justify a decision. Finally, models can be used to determine the relative contributions from different sources as a tool for tracking trends, monitoring compliance, and making policy decisions.
Modeling for air quality management purposes typically falls into two broad categories: dispersion modeling and receptor-based modeling. Briefly, dispersion models are used to predict ambient concentrations and receptor (or source apportionment) models use ambient data to determine the sources. They can be differentiated a few ways: on the required model inputs (i.e., meteorological data); on the spatial scale (global; regional-to-continental; local-to-regional; local); on the temporal scale (episodic models, long-term models); on the treatment of the transport equations (Eulerian, Lagrangian models); on the treatment of various processes (chemistry, wet and dry deposition); and on the complexity of the approach. The choice of model depends on a combination of the available data and the needs of the researcher.
|How do I do air quality modeling?|
The choice of model depends on a combination of the available data and the needs of the researcher. To help decide which model to use, see U.S. EPA's detailed recommendations. Once you decide which model is best for your situation, many of the models are available for direct download at the U.S. EPA Support Center for Regulatory Air Models (SCRAM).
It is important to involve the public. As with the other management activities related to the AQM process, it is critical to contact the regulated community and other affected parties, as the public should be consulted as part of the process.
To learn the basics of air dispersion modeling, you may take an on-line course offered by the Air Pollution Training Institute or read U.S. EPA's Citizens' Guide on Air Dispersion Modeling. If you are more advanced, you should visit the series of advanced courses on air quality modeling.