摘要
本文利用一个空间滤波器将物理量分解为天气尺度和次天气尺度,以两个路径相似但环流形势不同的台风暴雨作为例子,对不同尺度的环流及其动能平衡进行诊断研究,结果表明:中、低纬环流系统能否进行相互作用是决定台风暴雨强度和范围的一个重要条件。在8209号台风过程中,这种相互作用是明显的,因而,8209号台风暴雨的强度和范围均显著大于8304号台风。同时,8209号台风暴雨的能量过程突出地反映在次天气尺度的动能场上,相反,在8304号台风过程中,以天气尺度的能量过程为主要的能量特征。本文还特别指出,不能简单地认为登陆台风是一个动能的“准封闭系统”,在8209号台风过程中,台风从中、低层向外输出的次天气尺度动能是造成台风环流之外暴雨的一个重要物理过程。
A low-pass filter is used to separate the flow into synoptic and subsynopticscalecomponents. There are two examples of typhoon storm rainfall-Andy (1982) andWayne (1983). They are with similar tracks, but their circulation types are different. The circulation types of different scales and kinetic energy balance are diagnosed. The results show that the interaction between low and mid-latitudes in Andy (1982) case is evident. Thus, the intensity and area of Andy( 1982) storm rainfall are greater obviously than those of Wayne (1983), while energy processes of Andy (1982) show mainly in subsynoptic-scale kinetic energy field but that of Wayne (1983) in synoptic-scale kinetic energy field. It should be indicated that the landing typhoon has not been considered as a quasi-closing system of kinetic energy. In Andy ( 1982) case, subsynoptic-scale kinetic energy, which is transported from the middle and the lower troposphere of Andy (9182), is an important physical process that brings about storm rainfall the typhoon.
出处
《大气科学》
CSCD
北大核心
1991年第3期111-117,共7页
Chinese Journal of Atmospheric Sciences
基金
台风基金
关键词
台风
暴雨
华东地区
研究
Filtering
Interaction
Kinetic energy balance.
