台风“莫拉克”路径诊断分析和模拟  

Diagnosis and Simulation of Track of Typhoon Morakot

作　　者：张建海 黄汉中 何勇 

机构地区：[1]浙江省绍兴市气象局,绍兴312000 [2]浙江省诸暨市气象局,诸暨311800

出　　处：《气象科技》2011年第2期182-189,共8页Meteorological Science and Technology

基　　金：浙江气象科技开放研究专项(KF2006009)资助

摘　　要：利用客观分析资料和数值模拟方法分析了0908号台风"莫拉克"穿越台湾岛前后在路径上出现的北翘、西折现象以及进入台湾海峡后移动异常缓慢的原因。结果表明:①台风靠近台湾岛后西太平洋副高减弱东撤,引导气流明显减弱,台风减速;台风进入台湾海峡后,北侧高压带的断裂和随后的重新连接加强是其路径偏北转向和移动缓慢的主因。②"莫拉克"存在与另外两个热带气旋"天鹅"和"艾涛"逆时针互旋的双台风效应,"艾涛"生成发展还延缓了副高加强西伸。③台湾岛地形敏感性试验表明,地形造成气压场西密东疏的非对称分布致使台风减速;地形诱生低压的发生发展使得台风在穿越台湾岛时出现了西折现象。④台风有向正变涡区和暖湿区移动的趋势,正变涡中心、正相当位温中心和台风中心连线与未来北翘和西折移向基本吻合,这在短时台风路径预报中具有指示意义。The causes of abrupt northward shifting,westward turning and extremely slow moving after entering the Taiwan Strait of Typhoon Morakot（0908） are analyzed by using the objective analysis data and numerical simulation methods.The results show：（1） The weakening and eastward withdrawing of the western Pacific subtropical high when the Typhoon moved close to the Taiwan Island made the typhoon slow down for its steering current obviously weakened.After the Typhoon entering the Taiwan Strait,the splitting,the subsequent rebuilding and the reinforcement are the main causes for its northward recurving and slow movement.（2） Typhoon Morakot has the Fujiwara effect of anticlockwise revolving around Typhoon Goni and Etau.Meanwhile,and the formation and development of Typhoon Etau delayed the westward extending of the western Pacific subtropical high.（3） Sensitivity tests to the Taiwan Island orography indicate that the terrain resulted in the asymmetric distribution of the pressure field,dense on the west and sparse on the east,and that the formation of a topographic low made the typhoon turn westward while traversing the Taiwan Island.（4） Typhoons tend to move towards the positive vorticity variation and warm/wet areas.The connecting line between positive vorticity variation center,positive equivalent potential temperature center,and typhoon center coincides with the direction of the typhoon＇s abrupt Northward shifting and westward turning afterwards,which has denotative meaning for the short-range forecast of typhoon tracks.

关 键 词：莫拉克 疑难路径 大尺度 多台风 地形影响 

分 类 号：P457.8[天文地球—大气科学及气象学]