Atmospheric dispersion models are computer programs that use mathematical algorithms to simulate how pollutants in the ambient atmosphere disperse and, in some cases, how they react in the atmosphere.

US Environmental Protection Agency models

Many of the dispersion models developed by or accepted for use by the U.S. Environmental Protection Agency (U.S. EPA) are accepted for use in many other countries as well. Those EPA models are grouped below into four categories.

Preferred and recommended models

Alternative models

Screening models

These are models that are often used before applying a refined air quality model to determine if refined modelling is needed.

Photochemical models

Photochemical air quality models have become widely utilized tools for assessing the effectiveness of control strategies adopted by regulatory agencies. These models are large-scale air quality models that simulate the changes of pollutant concentrations in the atmosphere by characterizing the chemical and physical processes in the atmosphere. These models are applied at multiple geographical scales ranging from local and regional to national and global.

Other models developed in the United States

Models developed in the United Kingdom

Models developed in continental Europe

The European Topic Centre on Air and Climate Change, which is part of the European Environment Agency (EEA), maintains an online Model Documentation System (MDS) that includes descriptions and other information for almost all of the dispersion models developed by the countries of Europe. The MDS currently (July 2012) contains 142 models, mostly developed in Europe. Of those 142 models, some were subjectively selected for inclusion here. Anyone interested in seeing the complete MDS can access it here. Some of the European models listed in the MDS are public domain and some are not. Many of them include a pre-processor module for the input of meteorological and other data, and many also include a post-processor module for graphing the output data and/or plotting the area impacted by the air pollutants on maps. The country of origin is included for each of the European models listed below.

Models developed in Australia

Models developed in Canada

Models developed in India

Air pollution dispersion models

Others