台风“利奇马”期间苏州大暴雨物理量诊断和微物理特征分析  

Physical quantity diagnosis and microphysical characteristics analysis of heavy rainstorm process in Suzhou during typhoon“Lekima”

作　　者：郭小浩 何琰 曹舒娅 赵静娴 吴玥 李睿 陈纾杨 GUO Xiaohao;HE Yan;CAO Shuya;ZHAO Jingxian;WU Yue;LI Rui;CHEN Shuyang(Suzhou Meteorological Bureau,Jiangsu Suzhou 215131,China;Wuzhong Meteorological Bureau,Jiangsu Suzhou 215128,China)

机构地区：[1]苏州市气象局,江苏苏州215131 [2]吴中区气象局,江苏苏州215128

出　　处：《气象科学》2021年第2期143-152,共10页Journal of the Meteorological Sciences

基　　金：江苏省气象局预报员专项(JSYBY201814);苏州市气象局自立课题(SZKJ201701)。

摘　　要：采用日本气象厅的最佳台风路径及强度资料、NCEP/NCAR逐6 h细网格再分析数据,分析了“利奇马”暴雨影响相关的云水含量、假相当位温、水汽通量散度、Q矢量、湿位涡等物理量;通过苏州雨滴谱资料,分析降雨强度、雨滴数密度、雨滴平均直径、雨滴含水量、雷达反射率因子、雨滴谱宽等微物理量特征。结果表明降水落区位于环境垂直风切变顺切的左侧。暴雨期间能量和水汽条件较好,低层Q矢量梯度使辐合上升增强,且其非对称性对暴雨落区有指示意义,湿位涡的发展也有利于暴雨的加强;另外,微物理分析表明冷云降水机制使降水效率大幅提高,雨滴谱能较好地反映台风降水特征,强降水主要由层状云中嵌入的对流降水引起。强降水时段雨滴谱的相关微物理量等都呈现较大值。Based on optimal typhoon track and intensity data from Japan Meteorological Agency and fine reanalysis data from NCEP/NCAR with interval of 6 hours,cloud water content,pseudo-equivalent potential temperature,vapor flux divergence,ageostrophic Q-vector and humidity potential vorticity during typhoon“Lekima”heavy rainstorm were analyzed.Meanwhile the data of raindrop spectrum was also adopted to analyze the precipitation intensity,number density,mean diameter,rain water content,radar reflectivity and the width of raindrop spectrum in the heavy rainstorm process in Suzhou during typhoon Lekima.The heavy rainstorm weather process in Suzhou during typhoon“Lekima”was analyzed in this paper.Results show that the precipitation area is located in the left of the environmental vertical wind shear.The condition of energy and water vapor is well during rainstorm.Q-vector gradient in the lower layer enhances the convergence and ascending motion.The asymmetry of the Q-vector gradient leads to the asymmetrical rainfall area.In addition,the development of the moist potential vorticity contributes to the strengthening of precipitation intensity.Furthermore,microphysical analysis shows that cold cloud precipitation mechanism plays an important role in precipitation efficiency,and raindrop size distribution can well reflect the precipitation characteristics of“Lekima”.Severe precipitation is mainly caused by convective precipitation embedded in stratiform cloud.Some microphysical quantities of Raindrop Size Distribution(RSD)have great performance during severe precipitation period.

关 键 词：利奇马 大暴雨 Q矢量 湿位涡 微物理特征 

分 类 号：P444[天文地球—大气科学及气象学]