摘要
利用中国气象局(CMA)最佳台风路径资料、地面加密自动站资料、SRTM30数据与ERA5再分析资料,对2013年相似路径台风“苏力”与“潭美”造成的福建暴雨落区差异的成因进行了分析。结果表明:(1)两次台风暴雨过程中福建强降水落区相对于台风移动路径方向的位置在其登陆前后有所不同,台风登陆前强降水均位于其路径北侧(闽东北),台风登陆后“苏力”强降水转至其路径南侧,而“潭美”强降水则位于路径附近。(2)台风登陆前“潭美”相较于“苏力”低纬存在强水汽输送带、闽东北上空高能高湿、低层辐合和高层辐散形成的抽吸作用,配合垂直正涡度场及地形抬升作用,该区域上升运动强且伸展高度高,导致其路径北侧降水强度更大、范围更大。(3)台风登陆后,“苏力”路径的南侧为强水汽辐合中心、气流汇合区及能量锋区,垂直正涡度柱南倾,上升运动强烈且强对流不稳定;“潭美”移动路径附近为强水汽辐合中心,西北气流与偏西气流汇合,维持暖湿结构,正涡度柱范围位于台风中心附近,该区域配合低层辐合、高层辐散,强垂直上升运动。受地形的引导、阻挡作用,低层气流加速辐合与抬升,有利于强降水的维持和加强。(4)台风强降水落区与环境风垂直切变有较好的对应关系,强降水区往往位于环境风垂直切变矢量下游和左侧;“苏力”和“潭美”登陆前后环境风垂直切变强弱和方向不同,可能是造成福建暴雨落区差异的重要原因之一。
Based on the best typhoon track data from CMA,intensive observations from automatic weather stations,SRTM30 data and ERA5 reanalysis data,we have performed the causality analysis of the difference of heavy rainfall distribution in Fujian caused by typhoons Soulik and Trami along similar tracks in 2013.Results are as follows.(1)Severe precipitation distribution in Fujian is different before and after typhoon landing with respect to the position of typhoon moving path during the two typhoon rainfall events mentioned above.The severe precipitation before both typhoons landing is located on the north side,namely northeast Fujian,of typhoon path.After typhoon landing,the severe precipitation caused by typhoon Soulik is located on the southern side of its path,and that caused by typhoon Trami locates near its path.(2)Before typhoon landing,comparing to the typhoon Soulik,typhoon Trami are associated with strong water vapor transport in the low latitudes.The warm and wet air produced the suction effect by convergence in the mid-and low-level and divergence in the upper level over the northeastern Fujian.Coordinating with the horizontal positive vorticity structure and the topographic lifting,it lead to the strong and high ascending motion in the northeastern Fujian and the intensive and extensive rainfall in the northern side of its path.(3)After typhoon landing,there are the strong vapor convergence center,airflow writhing zone and energy frontal zone in the southern side of Soulik typhoon path.In addition,the vertical positive vorticity column inclines southward,and ascending motion and convective instability are strong.While nearby the Trami moving path is a strong vapor convergence center,the northwest airflow and westerly airflow writhe,the warm and wet structure maintains,and the positive vorticity column is located near the typhoon center,coordinating with the convergence in the mid-and low-level and divergence in the upper level and the strong vertical ascending motion.Guided and blocked by the terrain,the convergence and uplift of the low-level airflow are accelerated,which is conducive to the maintenance and strengthening of severe precipitation.(4)There is a good correspondence between typhoon severe precipitation zone and ambient wind vertical shear(VWS).Severe precipitation zones locate mainly on the downstream and left side of the VWS.Before and after Soulik and Trami landfall,the strength and direction of the VWS are different,which may be one of the important reasons for the difference of heavy rainfall distribution in Fujian.
作者
黄惠镕
赵玉春
荀爱萍
陈健康
张伟
HUANG Huirong;ZHAO Yuchun;XUN Aiping;CHEN Jiankang;Zhang Wei(Xiamen Key Laboratory of Straits Meteorology,Xiamen 361012;Xiamen Meterolocial Bureau,Xiamen 361012)
出处
《暴雨灾害》
2021年第2期136-146,共11页
Torrential Rain and Disasters
基金
国家自然科学基金项目(41675047,41705045)
福建省气象局开放式气象科学研究基金项目(2019KX02)。
关键词
台风
移动路径
暴雨落区
环境风垂直切变
typhoon
moving path
heavy rainfall distribution
ambient wind vertical shear
