新疆及周边中亚地区大气可降水量分布的中亚低涡响应

Distribution of Precipitable Water Vapor of Low Vortex over Xinjiang and Surrounding Central Asia in Summer

中亚低涡是新疆及中亚地区主要降水系统,为了揭示其影响下的大气降水潜力,利用2003-2014年夏半年中亚低涡发生时的AIRS Version 6 Level 2卫星资料,对夏半年中亚低涡降水系统月际变化和不同类型路径的大气可降水量分布规律进行了分析。结果表明:①中亚低涡的南涡与北涡发生率明显不同。北涡占中亚低涡总发生率的68.31%,南涡占31.69%。其中,7、8月中亚低涡发生频次最高。②按照中亚低涡不同路径分类来看,各路径发生率明显不同,其中,向东南方向移动的中亚低涡发生率最高。③从月际变化来看,5-9月平均大气可降水量整体分布趋势为中亚地区高于中国新疆地区。新疆吐鲁番盆地和塔里木盆地高于沿山脉分布的地区。④从路径类型来看,北涡各路径平均大气可降水量分布趋势整体相似,各路径均有26 mm以上大范围高值区,南涡各路径含量整体偏小,大都在18 mm以下。上述研究将为新疆和中亚地区突发性强降水天气预报预警以及人工增水提供参考。

The Central Asian Vortex is the main precipitation system over Xinjiang and Central Asia.Based on the data of AIRS Version 6 Level 2 from Aqua satellite in summer during the period of 2003-2014,the monthly variation of the Central Asian Vortex precipitation and the distribution of atmospheric precipitable water vapor from different paths were analyzed so as to reveal the atmospheric precipitation potential.The results showed that:①Occurrence of the South Vortex and North Vortex over Central Asia was significantly different.The proportions of the North Vortex and the South Vortex accounted respectively for 68.51%and 31.69%of the total Central Asian Vortex.In July and August,the frequency of the vortex over Central Asia was the highest;②According to the classification of different paths of the Central Asian Vortex,the occurrence of the paths was obviously different,in which the occurrence of Central Asia Vortex moving southeastward was the highest;③According to the monthly variation,the distribution trend of average atmospheric water vapor during the period from May to September was higher over Central Asia than that over Xinjiang,China,and it was higher over the Turpan and Tarim basins in Xinjiang than that over the areas distributed along the mountains;④According to the path type,the distribution trend of average atmospheric water vapor of the North Vortex was similar.Compared with the North Vortex,there were the large high-value(26 mm or more)areas along the paths,and the water vapor content along the paths of the South Vortex was low and mostly less than 18 mm.The study results could be referred in weather forecast and artificially enhancing precipitation in Xinjiang and Central Asia.