一次变性台风再增强过程的敏感性试验

采用位涡反演技术与数值模拟相结合的方法,通过初值敏感性试验和物理量场的诊断分析,对台风变性后再度增强的影响因子和物理机制进行了深入的分析和研究。结果表明:台风低压由变性减弱转为发展增强主要是由于台风低压环流与西风带斜压锋区之间的相互作用所造成的,随着高空冷涡低槽的加深南下和台风低压的继续北上,两个系统之间的距离逐渐减小,西风带高空槽与台风低压之间相互作用的正反馈机制逐步成为台风变性后强烈加深发展的主要原因。

SENSITIVE EXPERIMENTS ON THE REINTENSIFICATION FOR THE EXTRATROPICAL TRANSITION TYPHOON

Through sensitive experiments of initial conditions and diagnostic analysis of physical fields,the influencing factors and physical mechanisms of the reintensification of typhoons after extratropical transition are analyzed and investigated thoroughly in terms of potential vorticity inversion and numerical simulation.The results show that the conversion from the weakening during the transition process to the reintensifying of typhoon depression mainly results from the interactions between the typhoon depression and westerly baroclinic frontal zones.The positive feedback mechanism between the two approaching systems,the southward upper-level cold trough and the northward typhoon depression,becomes gradually the main reason for the typhoon depression to deepen intensely.