复杂地形对山西省区域性暴雨的数值模拟试验

Numerical Simulation Experiment of Complex Terrain on Regional Rainstorm in Shanxi Province

为探究山西省复杂地形对暴雨的影响,利用中尺度天气模式WRF对2013年7月9~10日山西省特大暴雨天气过程进行模拟分析,基于山西省地形设计了3组地形敏感性试验,分析了地形对此次极端强降水的影响。结果表明,山西省复杂地形对暴雨特征(暴雨中心、暴雨强度)影响非常显著,当增高地形后,暴雨中心的垂直螺旋度大值区的区域明显变大,扰动位温大值区向东偏移,山西省南部水汽辐合增强,而当地形降低后,垂直螺旋度则明显缩小甚至消失,扰动位温也明显降低,中部水汽辐合增强。并结合动力条件、热力条件和水汽条件,阐述了山西省地形对暴雨发展过程的影响。

In order to explore the impact of complex terrain on rainstorm in Shanxi Province,the mesoscale weather model WRF was used to simulate and analyze the rainstorm process from July 9 to 10 in 2013.Based on the terrain in Shanxi Province,three sets of terrain sensitivity tests were designed to analyze the impact of the rainstorm process.The results show that the complex terrain in Shanxi Province has a significant impact on the characteristics of rainstorm(rainstorm center,rainstorm intensity).When the terrain is increased,the area of the maximum vertical helicity in the center of rainstorm becomes significantly larger,and the maximum disturbance potential temperature area shifts to the east.The water vapor convergence in Southern Shanxi is enhanced.When the terrain is reduced,the vertical helicity is significantly reduced or even disappeared,the disturbance potential temperature is also significantly reduced,and the water vapor convergence in the middle is enhanced.Combined with dynamic conditions,thermal conditions and water vapor conditions,