Match: A Mesoscale Atmospheric Dispersion Model and Its Application to Air Pollution Assessments in Sweden

Abstract

The MATCH (Mesoscale Atmospheric Transport and CHemistry) model has been developed as a tool for air pollution assessment studies on different geographical scales. It has been used as a basis for decision making concerning environmental protection within Sweden or subregions of Sweden.

MATCH is an Eulerian atmospheric dispersion model, including physical and chemical processes governing sources, atmospheric transport and sinks of oxidized sulfur and oxidized and reduced nitrogen. In its standard configuration the model has three levels in the vertical, where the second layer is variable in height and follows the mixing height. The mixing height is derived from standard meteorological fields and varies in both space and time.

Using the MATCH system, air pollution contributions from different source types like traffic, industry, shipping, farming etc can be obtained. Using a combination of air and precipitation chemistry measurements and the MATCH model, the contribution of air pollution and deposition from long range transport can be quantified in the model region. A first tentative comparison between the EMEP and MATCH calculations indicate that the relations between local/regional contributions and long range transport are similar for deposition of oxidized and reduced nitrogen, but for oxidized sulfur the MATCH system gives a somewhat smaller influence from local/regional sources compared to what is obtained from EMEP.