Evaluation of a Model Performance with Data from a Large Power Plant

Air pollution models for local-scale dispersion were developed during the years 1980–84 at the Danish Air Pollution Laboratory. The result of the project is the OML-model, a new operational air quality model. The OML-model is based on the well-known Gaussian plume formulation but the simulation of dispersion processes has been improved compared to earlier models. The improvement was obtained by describing the dispersion processes in terms of physical parameters which have been shown by recent research to be of basic importance to boundary-layer turbulence. During the period April 1984 to March 1985, an extensive dispersion experiment was conducted in the surroundings of the 1440 MW coal fired power plant, the Asnaes Power Plant, Denmark. The data set consist of one full year of 1/2-hourly measurements of SO2-concentrations from ten monitoring stations. Meteorological measurements were made at a nearby meteorological mast. Hourly emission inventory has been performed for the power plant as well as for other major nearby sources. Results from the model evaluation are presented in the paper Detailed analyses of the OML-model performance showed that the model exhibits a heigh degree of accuracy in predicting dispersion of SO2-pollution from the power plant. A special emphasis was put on evaluation of the physical behaviour of the model.