近49年新疆阿克苏地区雷暴气候特征分析

Characteristics of Thunderstorms in Aksu, Xinjiang in Recent 49 Years

利用新疆阿克苏地区6个气象站1960年-2008年49年雷暴资料，对新疆阿克苏地区雷暴时空分布特征和变化规律进行了分析研究。结果表明：①雷暴日数75％以上都集中在夏季，持续期盆地谷地最长、沙漠边缘最短；地势较高的盆地谷地为雷暴的高发区，沙漠地带雷暴最少；②新疆阿克苏地区雷暴日数总体呈下降趋势，1990年-2008年累计距平均为-50．9d，沙漠边缘雷暴年代波动最大；③各测站年雷暴日数下降趋势在-1．05d／10a—-3．0d，10a，1990年代开始下降趋势加大，乌什、阿拉尔下降趋势较大，分别为-16．86d／10a和-8．4d／10a，相当于每10年减少34．5％和46．4％。夏季变化幅度较小，1990年-2008年乌什、阿拉尔倾向率分别为-4．64d／10a和-2．24d／10a，相当于每10年减少9．5％和12．4％。

Based on the thunderstorm data of six weather stations in Aksu, Xinjiang from 1960 to 2008, the temporal and spatial distribution and changing were analyzed. The results showed： （1） the number of thunderstorm days over 75% are concentrated in the summer, the duration of thunderstorm is the longest in the valley and basin and the shortest in the edge of the desert. There were the most thunderstorms in the valley and basin and the least thunderstorm in the desert. （2） thunderstorm days in Aksu, Xinjiang had a downward trend. The accumulated anomaly of thunderstorm days from 1990 to 2008 is 50.9d and the deeadal variation of thunderstorm was the greatest in the edge of the desert. （3） the thunderstorm days of each station downward trend was from -1.05d/10a to -3.0 d / 10a. The downward trend increased in 1990＇s. The downward trend was larger in Wushi and Alar. Wushi and Alar decreased -16.86d/10a and -8.4d/10a respectively and it reduced about 34.5% and 46.4% every ten years. Summer changed little. Trend rate of Wushi and Alar was-4.64d/10a and -2.24d/10a in 1990 -2 008. It reduced about 9.5% - q112. 4% every ten years.