1822号台风“山竹”引起浙江东北部大暴雨成因分析  

Causes analysis on the heavy rainfall in northeastern Zhejiang related to the typhoon“Mangkhut”(1822)

作　　者：方艳莹 钱燕珍 申华羽 吕劲文 薛国强 FANG Yan-ying;QIAN Yan-zhen;SHEN Hua-yu;LYU Jin-wen;XUE Guo-qiang(Ningbo Meteorological Service Center,Ningbo 315012 China;Ningbo Meteorological Disaster Warning Center,Ningbo 315012 China;Ningbo Meteorological Observatory,Ningbo 315012 China)

机构地区：[1]宁波市气象服务中心,浙江宁波315012 [2]宁波市气象灾害应急预警中心,浙江宁波315012 [3]宁波市气象台,浙江宁波315012

出　　处：《海洋预报》2020年第4期86-96,共11页Marine Forecasts

基　　金：宁波市“科技创新2025”重大专项(2019B10025);浙江省宁波市科技局项目(2014C50024)。

摘　　要：利用自动站资料、卫星云图以及NCEP再分析资料等,分析了1822号台风“山竹”登陆广东期间浙江东北部出现大暴雨的成因。结果表明:强降水发生在台风“山竹”登陆广东后减弱过程期间,伴有中尺度对流系统的发展,是由副热带高压、台风倒槽以及弱冷空气先后影响共同造成的;当对流不稳定时,与暖湿气流相关的湿位涡水平分量发展可触发垂直涡度的增长,使暴雨过程加强;强降水常发生在能量锋区附近,能量场的位置和梯度大小对此次强降水预报有12 h左右的提前量;来自台风东侧低层强的水汽输入和水汽辐合提供了本次强降水的水汽条件,水汽通量分布和水汽通量散度的增减相比雨量的增减有6 h左右的提前。This paper analyzes the cause of the heavy rainfall in northeastern Zhejiang after the typhoon“Mangkhut”(1822)made landfall in Guangdong using automatic weather station data,satellite images and NECP reanalysis data.The results show that the heavy rainfall occurred during the weakening process of the typhoon landing in Guangdong,accompanied by the development of mesoscale convective system,which was caused by the subtropical high,the typhoon inverted trough and the weak cold air in succession.When the atmosphere was unstable,the development of the horizontal component of the moist potential vorticity can trigger the increase of the vertical vorticity,which strengthened the heavy rainfall process.The heavy rainfall occurred near the energy front,and the position and gradient of the energy field can be used to forecast this strong precipitation with a 12 h lead time.The water vapor input and the water vapor convergence from the low level on the east of the typhoon provided the water vapor conditions for the heavy rainfall.The increase and decrease of the water vapor flux and the water vapor flux divergence led the increase and decrease of the rainfall by about 6 h.

关 键 词：台风“山竹” 大暴雨 浙江东北部 对流不稳定 

分 类 号：P444[天文地球—大气科学及气象学]