黄河中游暴雨的水汽特征

黄河中游地区区域性暴雨的爆发及强弱与低纬天气系统有着密切的关系，普查了１９８２－１９９１年６－９月间黄河中游地区区域性暴雨过程。分析了中、低纬天气系统相互作用下，该区出现区域性暴雨时的水汽来源、输送及辐合、辐散的空间结构特征。结果表明：该区产生区域性暴雨以上强度降水所需水汽的７５％以上来自台风，台风所提供的水汽主要是从７００ｈＰａ以下输入到该区，且水汽输送通道中心始络维持在８５０ｈＰａ附近。做低层

The Moisture Feature of Storm in the Middle Reaches of Huanghe River

he outbreak and intensity of regional storm in the middle reaches of Huanghe River is closely related to the low latitude synoptic system (especially typhoon). The regional storm pro-cess in middle reaches of Huanghe River during June to Sept in 1982-1991 has been investigated. As the regional storm appeared,the space-structure characteristics of moisture source, transportioon, convergence and divergence influenced by the interaction of middle and low latitude synoptic systems were analysed. It is shown that 75 Percent moisture of regional storm and upwards precipitation stems from typhoon,and the moisture source is located bellow 700hpa. The moisture channel center is maitained over 850hpa. The key factors of the regional storm and hard rain are the input capacity of low-level moisture. The movement direction of the moisture channel center is identical with the low-level southeast jet. Otherwise,the presence of the lower surface moisture forced divergence in the south and southeast of the storm region is benefit to the moist ture re-convergence towards the storm region.