新疆阿勒泰地区短时强降水流型及环境参数特征

Characteristics of Short-time Heavy Precipitation Weather Flowand Environmental Parameter of Altay Region in Xinjiang

利用新疆阿勒泰地区(简称阿勒泰地区)自动气象站逐时降水、常规及EC细等资料分析研究了2010-2016年5-9月45个短时强降水过程的环境流型、温度对数压力(T-logP)图形态和关键物理参数,并与中国中东部对比。结果表明,该地区短时强降水天气主要由中亚槽前型、中亚低涡型、西西伯利亚低槽(涡)型造成,前2种型6月发生最多,后者7月最多,并给出各天气型的高低空流型配置。大多数过程T-logP图温湿廓线呈上干冷下暖湿的"漏斗"状,对流层中低层或低层水汽较好,对流有效位能CAPE呈"瘦弱"的梭形,抬升凝结高度较低。总结出该地区短时强降水发生前主要天气型的关键环境参数平均值和阈值;该地区大多数环境参数阈值小于中国中东部地区,说明该地区比中国中东部地区更有利于触发短时强降水的发生。

In order to understand the characteristics of short-time heavy precipitation（≥ 10 mm · s-1） in Altay of north Xinjiang, using automatic weather stations, common and EC fine grids and so on in Altay region, The environmental flow patterns, T-logP chart, and key physical parameters from 45 times of short-time heavy precipi- tation during 2010-2016 were analyzed, and then compared the area with the eastern part of China. The result shows that the short-time heavy precipitation was caused largely by front type of central Asia trough and vortex and the low trough （vortex） type of West Siberia. The first two occur most in June and the latter one most in Ju- ly, and we extracted the flow pattern configurations of different weather patterns. In most processes, the profile of temperature and humidity looks like a funnel on T-logP chart, the upper part is dry and cold, and the lower part is warm and humid; the water vapor troposphere is better in middle low layer; CAPE shows a thin and weak spindle shape; Uplift condensation height is lower. In this area, average and threshold value of the key environ- mental parameters of the main weather types were summarized before short-time heavy precipitation, most envi- ronmental parameter thresholds are smaller than the central and eastern part of China, which shows that the region is more conducive to trigger short-time heavy precipitation than central and eastern regions of China.