台风“达维”(1210)非对称性结构及其对风雨分布的影响分析

A study on asymmetrical structure of typhoon Damrey( No.1210) and its impacts on wind field and precipitation distributions

针对台风登陆后常有的显著非对称性特征,以2012年10号台风"达维"为例,利用常规观测站、区域自动气象站、卫星云图和NCEP再分析资料等,采用天气学、统计学方法,定量地分析了非对称性台风在登陆后结构的变化及其对风雨的影响机制。研究表明:台风非对称结构对风雨的影响不仅表现在相对于台风中心不同象限量值上的差异,同时也表现在其量值分布形态的差异上;台风"达维"非对称降水差异的主要原因是位于东部象限的强上升区和西北象限的下沉稳定区;右前侧低空暖湿输送带和对流不稳定层结是产生强降水的主要原因。

In order to give more details about the asymmetric structure of typhoon after landing,a case study of typhoon Damrey was carried out by using the synoptic and statistical methods. The observation data from conventional and regional automatic weather stations,satellite imageries and NCEP reanalysis data sets were used to study the possible dynamic mechanism and impacts of asymmetric structure on wind field and precipitation. Results show that the asymmetric structure of typhoon Damrey leads to not only different distributions but also different patterns of wind field and precipitation in different quadrants. The upward movement in the east quadrant and the stable sinking in the northwest quadrant contribute to the asymmetric precipitation distribution. At the same time,the low level warm moist conveyer belt and convective instability are the main mechanism of heavy precipitation.