复杂地形城市冬季大气污染的数值模拟研究

Numerical Study on Air Pollution Concentration over Lanzhou Winterunder Complex Terrain

采用中尺度大气动力模式与大气扩散模式相结合的方法 ,针对复杂地形条件下兰州市冬季无明显冷空气入侵天气过程时段 (1994年 12月 2～ 3日 )的大气污染状况 ,进行污染物 (二氧化硫和烟尘 )浓度分布的数值模拟研究 ,分析了模拟的风场和气温层结随时间的变化以及污染物浓度的分布及其变化 ,进一步分析了模拟的风场和气温层结与污染物浓度分布的关系。结果表明 ,该模式系统对兰州市大气边界层结构及污染物浓度的分布有较好的模拟能力 。

In this study, concentration of air pollutant (SO 2and fume) during winter period without obvious weather event from 2 to 3 December 1994 over Lanzhou, a city of complex terrain, is simulated witha coupled, high-resolution atmosphere-diffuse modeling system. The meteorological conditions (wind and inverse temperature) prevailing during the period are analyzed based on simulation products of the Regional Atmospheric Modeling system (RAMS). And the dispersion of the air pollutant (SO 2and fume) over Lanzhou is studied with the use of the Hybrid Particle and Concentration Transport package model (HYPACT). The impacts of wind and inverse temperature on pollutant concentration are analyzed based on the simulating results. The results show that the changes of wind and inverse temperature have obvious influence on pollutant concentration, and that the modeling systems are suitable for simulating atmospheric boundary layer and air pollutant concentration over Lanzhou. This proves the feasibility of using the modeling systems to predict air quality over Lanzhou City.