中文摘要：

基于NCEP 1°×1°资料,且在高空探测和卫星云图的基础上,利用涡度方程分析了2009年6月28日四川盆地发生的区域暴雨过程,结果表明：①500 hPa环流变化与贝加尔湖南侧低槽扰动及高原切变线有关,在暴雨开始前后降水环流形势出现较快的调整,贝加尔湖冷槽南移影响四川盆地.700 hPa西昌一带的西南风加大,并在雨区具有中尺度结构的降水云团发展.②诊断分析表明,局地涡度分布对降水系统的发展具有重要作用,在短波槽扰动区域内,通常ζ/t〉0.暴雨临近时,正局地涡度变化区域偏北,槽偏北,雨区仍为负局地涡度.暴雨开始时,雨区上空转为正局地涡度.在700 hPa上,正局地涡度的分布也对低层降水系统发展起到重要作用,正局地涡度变化的分布首先是开始于盆地西北部,然后发展到暴雨区域,再逐渐往盆地南部发展,与云团移动路径和降水发生趋势较为一致.③一定程度上,当500和700 hPa两层的正局地涡度变化中心位置叠加在同一地方时,正涡度深厚,往往是暴雨发生的区域,因此正局地涡度变化可以作为判断降水落区的一个物理要素来参考.

英文摘要：

Using NCEP 1°×1°re-analysis data to analyze circulations character on heavy rain in Sichuan basin on 28th June 2009.The results show that firstly,the atmospheric circulations were relevant to high through of Baikal lake region,low vortex of Yunnan region and plateau shearing in 500 hPa.When heavy rain occurred,the cold through of Baikal lake region moved towards Sichuan basin and affected Sichuan basin.In 700 hPa,Southwest wind speeded up in Xichang and there was a meso-scale rain cloud-mass exiting in heavy rain region.Secondly,the physic diagnoses show that variation of local vorticity was essential to development of rain system,in through region,variation of local vorticity was plus.While heavy rain occurred,through appeared in north of Sichuan basin,during heavy rain time,there was plus variation of local vorticity in rain region in 700 hPa,plus variation of local vorticity was also important to development of rain system,and plus variation of local vorticity appeared in north of Sichuan basin firstly,then appeared in heavy rain regions,lastly heavy rain moved toward south of Sichuan basin.To some extent,when the area of plus variation of local vorticity was coincident between 500 hPa and 700 hPa,it was favorable for the formation of heavy rain.Therefore,plus variation of local vorticity was useful physic factor to judge rain areas.Thirdly,-βv was important to development of southwest in Xichang region.