北京区域近地边界层特征数值模拟

用非静力平衡的中尺度模式MM5.V3模拟了北京地区2000年夏季7月10日—11日的风速和温度场等边界层特征。模式所采用的水平分辨率为1 km，以天安门为中心，选取东西80 km南北100 km的区域进行模拟。模拟结果表明城郊之间存在明显夏季热岛效应，市区和郊区的温差最大可达6～8 ℃；边界层风场受西北特殊地形的影响，白天盛行由南往北的上坡风，夜间转为由北向南的下坡风。并用气象观测站实测资料对模拟结果进行了验证，验证表明模拟是准确的。模拟结果有助于了解北京地区区域气候的形成、污染物扩散及制定相关城市规划。

Numerical Simulation of Features of Surface Boundary-Layer over Beijing Area

The non-hydrostatic mesoscale model MM5.V3 is used to simulate the wind field, temperature field etc. of the atmospheric boundary layer over Beijing Area with the mesh resolution of 1km. The simulation results show that the numerical model can successfully simulate the heat island effect and the wind field and temperature field, which are affected by the complicated topography and urban heat island. The results show that: (1) The surface temperature in the central Beijing is 6--8℃ higher than that in the suburbs. (2) Due to the unique topography the wind of Beijing area during the day time is southern anabatic wind and is northern katabatic wind in the night.