斜压涡度的变化与台风暴雨的关系研究

台风暴雨作为台风引起的最主要灾害之一，一直被人们关注。台风常被认为是对称结构，但从实际状况来看台风的非对称性非常明显，所以有必要研究斜压性涡度在台风中的表现。在高分辨率数值模拟的基础上，通过引入斜压涡度的概念，分析和总结了斜压涡度在2009年台风“莫拉克”暴雨过程中的表现。通过模拟与分析得到如下的结果:斜压涡度和MPV对比，可以看出在登陆前和登陆后，明显低层斜压涡度有更强的异常信号，围绕台风内核呈现正负正的位相特点；从沿着台风中心时间剖面可以看出，登陆前斜压涡度低层多为负正负的位相，并且随着时间的推移，斜压涡度有从大气的高层向台风的移动中心传递的趋势，即在台风即将到达时原先的正涡度被替换为负涡度，所以对其移动有一定指示意义；在台风“莫拉克”过台湾岛时，其斜压涡度表现为负涡度消失，在山地附近有正涡度生成，完成过岛，台风中心被替换；斜压涡度的异常值主要位于大气的低层时，一般会产生较强的降水。 

STUDY ON THE RELATIONSHIP BETWEEN BAROCLINIC VORTICITY AND TYPHOON RAINSTORM

Typhoon rainstorm, as one of the major disasters caused by typhoons, has always been the focus of attention. From the actual atmospheric conditions, typhoons are often known as symmetrical structures. Asymmetry of the actual typhoons, however, is very obvious, so it is necessary to study the baroclinic vorticity in the performance of typhoons. Based on the high-resolution numerical simulation, the baroclinic vorticity is introduced to analyze and summarize the performance of the baroclinic vorticity during Typhoon Morakot in the year 2009. Compared with baroclinic vorticity with MPV, baroclinic vorticity has stronger anomalous signal before and after the landfall of typhoons, and it shows the positive-negative-positive phase characteristics around the inner core of typhoon. From the time profile of typhoon center, the lower layer of baroclinic vorticity is mostly negative-positive-negative phase characteristics before landfall. And along with time there is a tendency that baroclinic vorticity transfers from the upper layer to the center of the typhoon movement. When the typhoon is about to arrive, the original positive vorticity is replaced by negative vorticity. It has certain directive significance to the movement of typhoons. The negative baroclinic vorticity disappears when crossing the islands, and positive vorticity is generated near the mountain area. The negative baroclinic vorticity is replaced by the positive baroclinic vorticity. It is found that when the anomalous value of baroclinic vorticity is mainly located in the lower layer, heavy precipitation usually occurs.