1111号热带气旋“南玛都”异常路径成因分析

Analysis on the Cause of Unusual Track of 1111 Tropical Cyclone “Nanmadol”

本文利用NCEP／NCAR提供的GRIB码数据格式的1.0。×1.0。格点再分析资料、卫星云图和中央台的台风定位报资料，对“南玛都”在台湾海峡内移动缓慢的成因进行分析，结果表明：（1）多天气系统的影响，环境引导气流减弱，是“南玛都”移速减缓的大尺度环流背景。（2）台风风场结构中不对称强风区的转移，造成台风移动合力方向的改变，使“南玛都”在台湾海峡内移动缓慢、路径徘徊。（3）台风前进方向后侧强盛的对流发展，对台风西行北上起到一定牵制作用，造成“南玛都”在福建近海徘徊。（4）台风中心附近的垂直速度场及涡度场分布对台风的移向、移速有一定的预示作用。

Based on the NCEP/NCAR GRIB 1.0 ~ ~ 1.0 ~ reanalysis data, satellite images and the NMC＇s typhoon center location data, the cause of lingering and slow-moving of ＂Nanmadol＂ in the Taiwan Strait are analysed. The results indicate： （1） The interaction of multi-synoptic systems and the weak steering flow made the ＂Nanmadol＂ slowed down. （2） The transfer of the asymmetric strong winds area in typhoon wind field structure, which changed the composition of forces impacting typhoon, made it lingering and slowing down in the Taiwan Strait. （3） The intensifying deep convection behind the typhoon prevented it from northwestward moving, which made it lingering off the Fujian coast. （4） The distribution of the vertical velocity and the vorticity around the center of typhoon showed an indication to the direction and the speed of typhoon motion.