“温比亚”台风登陆前后大暴雨特征及成因分析  

Analysis on the characteristics and reasons of the heavy rainfall caused by landfalling typhoon “Rumbia”

作　　者：王毅 钱燕珍 段晶晶 郭宇光 方艳莹 WANG Yi;QIAN Yan-zhen;DUAN Jing-jing;GUO Yu-guang;FANG Yan-ying(Ningbo Meteorological Observatory,Ningbo 315012 China;Ningbo Meteorological Service Center,Ningbo 315012 China)

机构地区：[1]宁波市气象台,浙江宁波315012 [2]宁波市气象服务中心,浙江宁波315012

出　　处：《海洋预报》2020年第3期62-71,共10页Marine Forecasts

基　　金：浙江省气象局预报员专项(2018YBY03);浙江省宁波市科技局项目(2014C50024);浙江省宁波市自然科学基金项目(2018A610210)。

摘　　要：利用中尺度自动站加密资料、雷达和卫星资料以及NCEP全球分析资料,诊断分析1818号台风"温比亚"登陆前后大暴雨特征及其成因。结果表明:(1)台风登陆前后,降水具有时间集中、局地性强、雨强大等中尺度降水特征,强降水集中在距台风中心100 km以内的台风前进方向的左前部和后部,主要由两个移动性雨团和1个相对少动雨团产生,距台风中心25~50 km的降水量中心小时降水量普遍较大;(2)杭州湾区域地面辐合一方面加强了低空水汽辐合,另一方面促进了上升运动的发展和维持,使得中尺度对流雨团在宁波东北部至舟山一带发展加强,同时引导气流偏弱和地形作用导致台风在舟山附近移速减慢,延长了影响时间,造成了杭州湾附近区域的大暴雨;(3)地面辐合的增强和减弱对应于其后1 h降水的增大和减小;水汽通量散度的减小、增大与降水的增大、减小有较好的对应关系,水汽通量散度在-16×10^-5g/(cm^2·hPa·s)以下的时段降水较强;垂直螺旋度大值中心所对应区域未来6 h有强降水,垂直螺旋度的减小对应于该区域其后6 h降水的减弱。Based on the intensified automatic station data, radar, satellite and NCEP re-analysis data, the characteristics and reasons of heavy rainfall before and after landfalling typhoon"Rumbia"(2018) are analyzed in this study. The results show that the precipitation revealed mesoscale precipitation characteristics of short period, strong locality and heavy rainfall. Heavy rainfall mainly located in the left front and back of the typhoon moving direction within 100 km from the typhoon center, which was mainly generated by two moving rain mass and one relatively static rain mass. The hourly precipitation within 25~50 km from the typhoon center was generally large. The convergence of surface wind over Hangzhou bay strengthened the convergence of water vapor flux in lower air layers and boosted and sustain the ascending motion, which intensified the mesoscale convective rain mass between northeast of Ningbo and Zhoushan. Meanwhile, the weak steering flow and terrain effect made typhoon"Rumbia"slow down near Zhoushan, which extended the impact time and caused heavy rainfall around Hangzhou bay. The strengthened and weakened convergence of the surface wind caused the increased and decreased precipitation in 1 hour, respectively. The decrease or increase of the water vapor flux was corresponding to the increase or decrease of the rainfall. The rainfall was strong when the divergence of water vapor flux was below-16×10^-5g/(cm^2· hPa · s). Heavy rainfall would occur in 6 hours around the center of large vertical helicity. The decrease of the vertical helicity indicated the decrease of rainfall in 6 hours.

关 键 词：“温比亚”台风 大暴雨 成因 诊断分析 

分 类 号：P732.2[天文地球—海洋科学]