摘要
利用NCEP每日4次全球预报场(GFS)分析资料、卫星云图资料以及实况观测台风路径、强度资料对0908号台风"莫拉克"在台湾登陆前后其强度、结构变化特征进行天气动力学诊断分析,从而为台风强度、结构预报提供参考依据。结果表明:(1)低层切向风大值区中心所在半径处的切向风非对称性幅度之切向平均值可作为诊断分析台风强度的一个重要参考指标;(2)"莫拉克"中心高层干位涡大值区具有沿着低层切向风大值区中心内侧的切向风梯度密集带向下延伸的趋势;(3)未考虑摩擦、湍流混合的柱坐标切向风运动方程主要有四项是决定切向风变化的,即切向风径向平流项、切向风垂直输送项、惯性离心力作用项以及地转偏向力作用项;(4)台风低层辐合中心在切向上具有沿着切向风梯度密集区移动、发展的趋势。
GFS （Global Forecast System） analytical data obtained by NCEP four times daily, satellite cloud image data and real-time observation data about the path and strength of Typhoon Morakot （2009） were employed to make a synoptic dynamics analysis on the variation of its strength and structure before and after the landing, with the aim of offering some reference for the strength and structure forecast of typhoons. The results show that the tangential mean value of the asymmetrical range of the tangential wind, located on the radius of the center of the strong tangential wind at low altitude, can be employed as an important reference for diagnosing the strength of typhoon. Secondly, the large dry potential vorticity area of the typhoon center at high altitude exhibits a tendency of downward extension along the intensive gradient zones of the tangential wind on the inner side of the center of the strong tangential wind at low altitude. Thirdly, the principal decisive factors for the variation of the tangential wind are the radial advection, the vertical transmission of the tangential wind, the inertia centrifugal force and the coriolis force. These four factors are part of the tangential wind movement equation based on a cylindrical coordinate without considering the combined effect of friction and turbulence. Lastly, the convergent center of the typhoon at low altitude tangentially tends to shift and develop alongside the intensive gradient zones of the tangential wind.
出处
《热带气象学报》
CSCD
北大核心
2012年第5期726-734,共9页
Journal of Tropical Meteorology
基金
国家基础研究发展项目规划"973"(2009CB421503)
国家自然科学基金项目(40975037
41075039)
江苏省优秀科技创新团队基金
江苏省高校优势学科建设工程资助项目(PAPD)共同资助
关键词
天气学
诊断分析
台风
切向风
干位涡
synoptic meteorology
diagnostic analysis
typhoon
tangential wind
dry potential vorticity
