不同云微物理方案对上海特大暴雨模拟影响的分析

利用中尺度数值预报模式WRF3.5，采用36、12和4 km三重嵌套，在积云参数化方案为BMJ条件下，选用WSM5、WSM6和Lin三种云微物理参数化方案，对发生在上海地区的两次典型特大暴雨（简称“0913”和“0825”）进行模拟试验和对比分析，探讨不同云微物理参数化方案对上海暴雨模拟的影响。结果表明:三种方案总体上都较好地模拟出两次特大暴雨过程，但在降水落区、降水中心、降水强度等方面仍存在差异。再利用地面自动站、观测站的实测雨量以及自动站与CMORPH降水产品融合的逐时降水量网格数据，结合K指数、相对湿度、垂直速度和涡度散度等物理诊断量，从降水落区、降水中心和降水强度等方面对三种云微物理参数化方案的模拟结果进行对比分析。此外，通过对三种方案主要参数的比较以及三种方案模拟的冰、雪、霰粒子混合比的垂直廓线对相应的模拟结果进行解释。结果显示:WSM5微物理方案能更好地模拟出强降水的范围，其模拟的降水量较实测偏大；WSM6方案模拟的降水落区略有偏移，降水量偏小；Lin方案模拟的降水落区偏移较大。 

Analysis of the Impact of Different Microphysics Parameterization Schemes in Simulating Heavy Rainfall Over Shanghai

In order to study the impact of physics parameterization schemes in the WRF model on rainstorm simulations, two typical heavy rainfall events ("0825" and "0913") over Shanghai are simulated. The study was carried out with BMJ cumulus parameterization scheme and three physics parameterization schemes (Lin et al, WSM5 and WSM6 scheme) under three horizontal resolutions of 36 km, 12 km and 4 km. The results indicated that all three physics schemes generally simulated the precipitation well, but they still differ in rainfall areas, rainfall center and intensity. By using the measured precipitation data of ground stations and the hourly rainfall grid data integrated from automatic stations and CMORPH, the paper analyzed the impact of different physics schemes on precipitation from the rainfall area, center and intensity, combined with K index, relative humidity, vertical velocity, vorticity, divergence and other physical diagnosis. Furthermore, the paper compared the difference among the three physics parameterization schemes, and explained the difference of the results by using the vertical profile of qsnow, qice and qgraupel. The results showed that the micro-physical WSM5 scheme can better simulate the rainfall area, but get heavier rain than the observation, and WSM6 can well simulate the rainfall intensity but drift a little in rainfall area, andthe simulated rainfall area of Lin has a drift.