影响广西热带气旋暴雨的环境流场和一些物理量特征分析

The Characteristics of the Physical Factors and Atmospheric Current Fields of the Typhoon Torrential Rain in Guangxi

通过综合利用ECMWF提供的热带风场、气压场、高度场等资料,对24例影响广西的热带气旋环境流场和一些物理量特征进行了较为深入的分析。结果表明:大多数热带气旋的发生、发展都与赤道西风急流向东扩展或热带气旋东侧南风急流向北扩展有关;造成广西大范围台风暴雨的因素不仅取决于台风登陆地点和登陆后的路径以及中心是否直接进入广西内陆有关,而且还与副热带高压脊线的位置和面积指数、强度指数的变化关系密切。登陆台风在影响广西的过程中,其台风东侧的偏南风急流中心涌进广西和正涡度中心进入广西对产生大范围的暴雨起着重要的作用。

This article provides some important evidences for the generation and development of the typhoon and the analysis of the atmospheric current field of its torrential rain with the ECMWF data of tropical wind field, atmospheric pressure field and height field, especially wind vector field in tropical areas. The analysis and comparison for 24 cases indicate that the generation and development of most of typhoons are related to western jet stream in equator extending eastward and southern jet stream in east side extending northward. The factor for Guangxi typhoon torrential rain in large scope not only depend on the landing place, the tracking, the center of typhoon if entering the inland of Guangxi, but also are closely related to the position of the ridge line of Subtropical High, square area index and intensity index. In typhoon's landing process, the factors that the southern jet stream center in its east side surges over Guangxi and the atmospheric vortex enters Guangxi play an important role for the typhoon torrential rain in large scope.