DISPERSION21 (also called DISPERSION 2.1) is a local scale air pollution dispersion model[1][2][3] developed by the air quality research unit at SMHI, the Swedish Meteorological and Hydrological Institute, located in Norrköping.[4][5]
The model is widely used in Sweden by local and regional environmental agencies, various industrial users, consultant services offered by SMHI and for educational purposes.
DISPERSION21 is intended as a tool for calculating air pollutant concentrations originating from industrial or urban air pollutant sources. The model is used in studies to evaluate effects on air quality from existing or planned sources. It is a local-scale Gaussian model including plume rise and building wake effects. A street canyon component with NOx-chemistry is included.[6]
Some of the specific features and capabilities of DISPLAY21 are: [6]
The meteorological preprocessor and the point source part of the model have been extensively evaluated against many datasets. The street canyon part of the model has been tested with highway data. The model has also been tested in extremely stable atmospheric situations with datasets from Lycksele in Sweden.[6][7]
As of June 2011, SMHI is adapting DISPERSION21 so as to fit into their two overall air quality and dispersion modeling systems known as SIMAIR and Airviro. The adaptation is currently ongoing and the latest version of DISPERSION21 is referred to DISPERSION21-beta.[8]