台风“韦帕”的非对称结构特征及其登陆异常的成因分析

Asymmetric structural characteristics of Typhoon Wipha and analysis of its landing anomaly

利用0.25°×0.25°分辨率的ERA5再分析资料,对201907号台风“韦帕”的环流形势、物理量场进行了诊断分析。结果表明,“韦帕”具有非对称结构,强度稳定,移速缓慢,路径复杂,降水量大,维持时间长,影响范围广的特点;副高减弱东撤、“双台风效应”与“韦帕”自身的不对称结构导致台风路径多次转折;西南季风带来的丰沛水汽使台风持续维持热带风暴级别,并给海南、广东、广西带来了强降水;水汽通量散度辐合和上升运动与降水落区有较好的对应关系,中心强度与同时段降水量级呈正相关。

Using the ERA5 reanalysis data with a resolution of 0.25°×0.25°,the circulation situation and physical quantity field of Typhoon Weipa were diagnosed and analyzed.The results showed that Weipa had characteristics of asymmetric structure,stable strength,slow moving speed,complicated path,large precipitation,long maintenance time,and wide influence.The weakening of the subtropical high,the double typhoon effect and the asymmetric structure of the Weipa itself caused the multiple turns of typhoon path.The abundant water vapor brought by the southwest monsoon made the typhoon maintain the level of tropical storm and brought heavy rainfall to Hainan,Guangdong and Guangxi.The convergence and upward movement of water vapor flux divergence had a good corresponding relationship with the precipitation area,and the central intensity had a positive correlation with the precipitation magnitude in the same period.