Numerical regional air quality forecast tests over the mainland of China

The paper gives a general description of a numerical regional-scale air qua lity forecast model, with emphasis on solution schemes for all possible pro cesses (emissions, transport, deposition, chemistry, and initial boundary c onditions) considered in the Eulerian transport/deposition model. In order to improve forecast efficiency we first introduce a looking-up table method for treatment of NOx and ozone chemical processes instead of the coupling method. Meteorological field is forecasted by the Eta model, which is drive n by NCEP data. Several-week regional-scale air quality in China is forecas ted using the numerical model system. Comparison and analysis indicate that the air quality levels of key cities over China and the time evolution of pollutants over most places of China can well be forecasted by the numerica l model system. Further improvements in some important aspects are needed a nd presented.