中文摘要：

对北京大学的三维复杂地形中尺度数值模式进行了适当改进，引入第2代陆面过程模式的参数化方案，在计算地表能量水分收支时更加注重植被的影响，根据植物生态和土壤的地理分布特征确定陆面参数。结果表明，改进后的模式在模拟夏季北京气温场、风场、湿度场时都取得令人满意的效果。模拟结果可为了解北京地区区域气候的形成、污染物的扩散及城市规划提供参考和帮助。

英文摘要：

The meso-seale urban atmospheric boundary layer model of Peking University, with three-dimensional complex topography, was improved by introducing the second generation land-surface model, which paid more attention to the effect of vegetable coverage when computing land-surface water balance. The improved model was used to simulate temperature, wind and humidity fields over Beijing in summer. It is found that the model can provide acceptable results compared with observations. The simulation results are important to understand the local climate over Beijing area and the feature of diffusion of pollutants, and are helpful for making practical urban design.