台风“鲇鱼”异常路径的诊断分析和数值模拟

从高空环流和基本气流的演变对2010年第13号台风＂鲶鱼＂进入南海以后路径发生向北＂急翘＂的大环流形势进行分析,并应用wrf模式输出的高分辨率资料,对台风中心附近的风场、温度场和θse场的分布进行探讨,得出：＂鲇鱼＂进入南海后,路径发生向北＂急翘＂是由于青藏高压增强并向东移,致使其前部高空槽加深发展,切断了华南高压和副热带高压的联系,并使华南高压南落至中南半岛一带,使台风西行受阻,逐渐转为北移。同时越赤道气流的北涌,使基本气流从东北气流转为西南气流,北偏东移动趋势加大。500～700hPa两层引导气流与＂鲶鱼＂路径有很好的对应关系。最大风速区的水平和垂直结构将影响台风移动的路径,台风中心的有向风速低值区移动的趋势,最大风速区的垂直尺度的变化对台风移动有指导意义。温度场的水平和垂直分布也将影响台风的移动路径,西侧冷空气的入侵使台风偏西移动的趋势减弱,台风中心有向等厚度低值区移动的趋势。θse的高能舌的分布,有利台风向北或北偏东方向移动。

Diagnosis and Numerical Simulation of the Unusual Track of Meigi（1013）

Basing on the upper air circulation and the evolution of the basic flow,the path abruptly northward turning after Typhoon No.13 of 2010"Meigi"entering the South China Sea was analyzed.Using data output from WRF mode,the distribution of wind field,temperature field and se were also analyzed.The results show that Qinghai-Xizang high enhances and eastward moves,resulting in the front upper trough development and cutting off the contact between South China High and Subtropical High.Cause the South China High moves southward to indo-china peninsula,Meigi’s path abruptly changed from west to north.The cross-equatorial airflow northward rush,resulting in the northeast airflow turning to southwesterly airstream,which is conducive to typhoon "Meigi"moving northeast.There is a good correspondence between the steering flow of 500 ～ 700 hPa and "Meigi"path.The horizontal and vertical structure of the maximum wind region affect the path of the typhoon.The typhoon center tends to move to the small value area of wind speed.The vertical change of maximum wind,the horizontal and vertical distribution of temperature will guide typhoon movement.Typhoon center is inclined to the low value area of the height field.The cold air invasion of the west side(The distribution of high se value)makes typhoon moved west(north and northeast)trend weakening(strengthing).