The characters for the boundary layer and mechanism of acid rain formation in the Qingdao area,China

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The characters for the boundary layer and mechanism of acid rain formation in the Qingdao area,China

The vertical distributions of the wind field and temperature field of the boundary layer were very peculiar in Qingdao area, China. Under the height of 1500m, the wind field appeared as one pike two valley type: the wind speed was relatively low near surface, got bigger between 300m to 400m, decreased over 500m, and increased again gradually over 1000m. The temperature stratification was stable in the morning and evening, and it became unstable below 200m after noon. As far as mixed layer was concerned, it was not very high, generally about 400m, sometimes it reached 700m high. Multiple layer inversion often appeared in low altitude. Northern wind was prevailing in winter, so southern in summer. The wind field was often influenced by Jianghuai cyclone and Huanghuai cyclone. Convergence air current between lower level and higher level emerged when the cyclones passed Qingdao area. Introducing straight and shear air current, pollutants emitted from point sources were modeled by advection diffusion equation. The result indicated that pollutants were transported far away under one straight air current. In rainy days, pollutants were accumulated in local area and the concentrations were high. When wind direction appeared shear between higher level and lower level,the transportation of pollutants was more limited. In rain days,acid rain was form by chemical process at a near distance.