采用NCEP再分析资料,通过诊断分析与数值模拟方法,研究探讨"莫拉克"路径异常的可能原因.结果表明:(1)"莫拉克"的移动主要还是受副高南侧偏东气流的引导;"莫拉克"登陆台湾前的移速缓慢主要的影响因素包括这个阶段东侧热带低压"艾涛"的生成对副高引导气流的减弱作用以及大陆高压的阻挡作用;副高主体减弱东退,西南气流的作用以及双台风效应是"莫拉克"北折的主要原因;(2)数值模拟控制试验能较好地模拟出"莫拉克"的移动路径,但是对台风强度的模拟效果不好;两组地形敏感性试验相对于控制试验的模拟路径偏差均较小,台湾岛地形对"莫拉克"移向和移速的影响不显著.%Using the NECP reanalysis data, the unusual track of "Morakot" is investigated through diagnostic analysis and numerical simulation in this paper. Results show that:(1)The movement of "Morakot" is mainly affected by the eastern steering flow of the subtropical high. The tropical depression "Etau" and the mainland high weaken the steering effect of the environmental flow on "Morakot". The weakened environmental flow is the major reason for the slow movement of "Morakot" before landing on Taiwan. The eastward retreating and weakening of the subtropical high,the southwestern current,as well as the binary interaction,play important roles when "Morakot" is turning to north.(2) The track of "Morakot" can be successfully simulated by the control test of numerical simulation,but the intensity of typhoon; The deviation of two terrain sensitivity tests relative to the control test of numerical simulation is small. The influence of terrain of Taiwan Island on the direction and speed of typhoon, moving is not significant.
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