青岛地区边界层特征及酸雨成因

青岛地区边界层风场与温度场垂直分布很特殊，在１５００ｍ高度以下风场，近地面层风速较小，３００—４００ｍ高度风速较大，５００ｍ以上风速减小，１０００ｍ以上又逐渐增大．温度层结早晚稳定，午后２００ｍ以下不稳定，混合层不高，一般在４００ｍ左右，有时可达７００ｍ，低空经常出现多层逆温．冬季盛行偏北风，夏季盛行偏南风，并经常受江淮气旋和黄淮气旋影响，气旋经过青岛地区时，流场经常出现上、下辐合气流．引入平直和上、下切变两种气流，应用平流扩散方程，对青岛地区连续点源所排放的污染物作模式计算，结果表明，在单一平直气流时，污染物传输较远，但浓度轴线也在一定距离上与地面相交．尤其是在雨天，污染物只在局地散布，浓度较大．当风向出现上、下层切变时，污染物传输范围受限制，这些污染物质在雨天经过化学变化即在近距离形成酸雨．

CHARACTER OF THE BOUNDARY LAYER AND CAUSE OF ACID RAIN IN THE TSINGDAO AREA

Vertical distribution of the wind field and temperature field at the boundary layer in Tsingdao Area was found to be unique.Under the height of 1500m,the wind field appears one front two valleys type.For wind speed from ground up,it is relatively low for ground layer,reachs a maximum value between 300m to 400m,reduces over 500m, and increases again gradually above 1000m.As for temperature stratification,it appears stable in the morning and in the evening,and unstable under 200m after noon.As far as mixed layer is concerned,it appears aroung 400m and sometimes can attain 700m.Multiple layer inversiion often emerges in lower altitude.Wind to north is prevailing in winter,so is wind to sourth in summer.And they are often affected by Jianghuai and Haunghuai cyclones.Convergence air current between lower levers and higher levers emerges when the cyclone pass Tsingdao area.Specific point source can be calculated by introducing straight and shear air currents in conjunction with advection diffusion equation.The result indicates that pollutant will be transferred farther under one straight air current,while the concentration axis inclines downward and then meet the ground in some distance.Especially in rainy days,pollutants scatter only in the local area and the concentration is high.When wind direction appears shear between higher and lower levers,the pollutant transferring limits are more limited.And then acid rain will form by chemical changes of these pollutants at a short distance in rainy days.