中文摘要：

中国卫星FY-3A水汽产品为大气水汽混合比,对大气各层水汽条件具有精细化描述能力。将卫星水汽混合比空间分布与区域流场对应叠加,进行综合量化分析,是目前卫星监测反演数据研究分析与业务应用的形式之一。由于卫星数据与流场数据为非同源数据,具有各自的坐标系,综合分析需要将坐标系统一,卫星坐标系随时间变化,因此向固定的流场坐标系转化。整个数据预处理过程,包括卫星数据插值至标准等压面层,卫星轨道网格转为经纬等距标准网格;双权重法异常数据剔除;平滑滤除高分辨率＂噪音＂;十折交叉相关检验确认卫星资料精细化特征保持良好。对流场分析首先选择关键系统,江淮梅雨强降水系统主要为浅薄低涡和辐合线,近5 a的统计显示3/5的低涡活跃在江南,2/3的辐合线活跃在淮北。诊断分析合成的江淮梅雨强降水典型系统,获得辐合线系统纬向湿度锋区更强,低涡系统湿舌经向度大,显示更多干湿气团混合。进而将预处理后的FY-3A水汽分布与强降水系统低层流场对应时刻综合比对,结果显示：与流场气旋性辐合区对应的卫星湿区对强降水落区具有精细化指示性。同时FY-3A湿度产品计算的大气低层（1 000~850 h Pa）可降水量、以及降水区对应的假相当位温高能区及高能锋区,均与降水强度呈正比关系。将卫星水汽资料诊断方法应用于近海海域,可估测系统强降水落区以及降水强度,有利于改善海上缺乏降水观测站的问题。

英文摘要：

The air-moisture ratio is one of the products of the Chinese FY-3A satellite.The product enables atmospheric moisture conditions to be described at fine scale.By overlapping the air-moisture ratio field of FY-3A and the wind streamline field at low level together,the quantitative diagnostic and pre-estimate on precipitation over local area can be done.Due to the fact that the satellite data and reanalysis data come from different digital sources,and have their own coordinate systems,it is needed to build the same coordinate as a base for both datasets.The satellite coordinate changes with time as its covering area is different to any given position on Earth,so it needs to transfer the satellite coordinate into the coordinate of the wind streamline fields.The whole data preprocessing includes the following steps：interpolation of the vertical standard pressure levels from the satellite＇s own pressure levels;switching the satellite orbit coordinate into the traditional latitude-longitude coordinate;deleting outliers via the Bi-weight Check method,smoothing the data field and removing the data ＂noise＂ by the nine smooth method;Testing preprocessing results via cross-correlation testing,to check that the fine-scale features of satellite data are still keep satisfactory.For analysis of the wind streamline fields,key systems of heavy rainfall need to be determined at first.According to 5 year （2009-2013）statistics,the shallow low vortex and convergence line are two key system types for heavy rainfall over the Jianghui Valley during the Meiyu season.Three of five low vortices are active in the downstream area of Changjiang River,and two of three convergence lines are active in the Huaihe Basin.Synthetic analysis of these typical systems according to their different types shows that the convergence line is associated with a moisture front that has a stronger latitude directional,whereas the low vortex is associated with a longitudinally directed wet tongue and more blending of the wet and dry air masses.Furthe