平均螺旋度在强降水过程中的诊断分析  

DIAGNOSIS OF A HEAVY RAIN BY USE OF AVERAGE STORM-RELATIVE HELICITY

作　　者：黄勇[1] 张晓芳[1] 陆汉城[1] 

机构地区：[1]解放军理工大学气象学院,南京211101

出　　处：《气象科学》2006年第2期171-176,共6页Journal of the Meteorological Sciences

基　　金：国家自然科学基金项目(编号:40175012);总参重点科研项目共同资助

摘　　要：本文引入按高度平均的螺旋度-ASRH(Average Storm-Relative Helicity)的概念,为了在螺旋度的诊断分析中,同时考虑高低层效应。利用ASRH分析了2003年6、7月江淮地区、河南和陕西一带的一次大暴雨过程,结果表明,当高低层ASRH匹配较好时,ASRH的大值中心及其演变较好地对应了暴雨中心的位置及演变,ASRH的变化和暴雨演变有一定的因果关系,较大的ASRH可能是暴雨及中尺度系统发生发展的机制之一。In this paper, the ASRH （Average Storm-Relative Helicity） is introduced and the expression of ASRH is given to analysis of a heavy rainfall event according the theory of storm-relative helicity. In the diagnosis of storm-relative helicity,we considered the effect of upper and lower level storm-relative helicity at the same time. A diagnosis is made using ASRH on the heavy rain over the Jianghuai area, Henan and Shanxi region in June, July 2003. The results showed that the area and development of rainstorm is closed relevant with the big value center and evolution of average storm-relatlve helicity. When the correspondence of the upper and lower level ASRH is very well, some causality existed between the change of ASRH and the evolvement of heavy rain. ASRH perhaps is one of the mechanism of development of Mesoscale system.

关 键 词：平均螺旋度 暴雨 诊断分析 

分 类 号：P458[天文地球—大气科学及气象学]