近10a新疆短时强降水湿度层结及大气能量结构特征分析

Humidity and Unstable Stratification Characteristic of Short-time Heavy Rainfall in Xinjing in Recent Ten Years

为更好地把握中亚低涡造成新疆短时强降水天气过程的机理特征,利用温度露点温度廓线图(T-lnP图)和大气位温-风矢能量图(V-3θ图)研究了中亚低涡背景下新疆短时强降水的湿度特征和大气能量结构特征。主要结论有:(1)根据对短时强降水T-lnP图及湿度特征的分析统计,将短时强降水分成三类:对流层高低层干而中层湿度大型、对流层中层干燥型、对流层整层湿度都显著型。其中第一类最多,占短时强降水总个例的60%;而第二类和第三类分别占27.5%、12.5%。(2)一般在短时强降水天气发生前V-3θ图特征为:三条θ曲线呈曲折增长;有"顺滚流"结构存在;有"蜂腰"形构造;有较为浅薄的超低温层存在。

To better understand the machanism of short-time heavy rainfall in Xinjing under the background of Central Asian vortex,this paper analyzed the humidity and atmospheric energy structure characteristic of short-time heavy rainfall in Xinjing under the background of Central Asian vortex by using T-lnP plot and V-3兹plot,during the on May to September During2005-2014.We found that the short-time heavy rainfall classified to three types by analyzing the form of T-lnP plot,and the first type short-time heavy rainfall(heavy humidity at middle troposphere)was the most,accounted for60%.There were low CAPE before short-time heavy rainfall took place.The unstable stratification,wasp-waisted potential temperature line,the ultra-low temperature and the development of tumble can be seen obviously in V-3兹plot before short-time heavy rainfall took place.