2004年7月10日北京局地暴雨数值模拟分析

利用中尺度数值模拟结果,对2004年7月10日北京局地暴雨的中尺度系统的结构特征及其发生发展的原因进行了初步分析,结果表明:MCS在对流层中低层表现为中尺度辐合线和低压,在其发展强盛阶段,具有低层辐合、高层辐散的高、低空最佳配置以及暴雨区上空垂直上升运动强烈发展的结构特征;暴雨发生前,地表感热、潜热通量等边界层非绝热过程造成气温升高、气压下降、湿度增大,影响对流层中低层风场的分布,对暴雨的发生发展起了重要的作用.

Numerical Simulation and Analysis of a Local Storm in Beijing on 10 July 2004

The mesosc.ale structure and development reasons for a local storm in Beijing on 10 July 2004 are investigated by using the mesoscale numerical simulation. The results indicate that the MCS are the mesoscale convergence line and low pressure system in the mid- and low-level, with the convergence in the low level, divergence in the high level and strong ascending motion during the strong development stage. Before the heavy rain, the surface sensible and latent heat fluxes resulted in the temperature increase, pressure decrease and the water vapor accumulation, which influenced the wind distribution and played an important role on the formation and development of the local storm.