热带气旋Meranti(2010)异常路径的成因分析

Cause analysis on abnormal track of tropical cyclone Meranti(2010)

采用MTSAT2卫星红外云图资料及NCEP/NCAR再分析资料,研究了热带气旋Meranti(2010)异常路径的成因。结果表明:Meranti的路径由西行、打转、北上三个阶段组成。在西行、北上阶段,环境场引导流起着主要作用,Meranti的非对称结构对其也有一定影响,非对称对流系统的作用较弱。在打转阶段,环境场引导流和非对称结构均不能解释Meranti打转的原因,而非对称对流系统则起着主要作用。不同阶段的Meranti外缘线的分形维数特征存在明显区别。在西行、北上阶段,其分形维数处于高值段且变化平缓;在打转阶段,则处于低值段且变化较大。

Based on the infrared satellite images of MTSAT2 and NCEP / NCAR reanalysis data,this paper studies the cause of abnormal track of tropical cyclone Meranti（ 2010）. The track of Meranti consists of three stages： the westward moving phase,the rotating phase and the northward moving phase. Results show that the environmental steering flow plays a key role in the westward moving phase and the northward moving phase,and the asymmetric structure of Meranti also has a certain influence,whereas the influence of asymmetric convection system is weak. The asymmetric convection system plays a main role in the rotating phase,including interaction of Meranti with two neighboring meso-scale vortices,the Meranti escaping northeastward in the binary vortex process and so on. It also shows that the fractal dimension of Meranti border line in the rotating phase is obviously different from that in the westward or northward moving phase,which is significantly lower with notable fluctuations.