Based on ground hourly rainfall, conventional observations, 1° × 1° NCEP/NCAR reanalysis and ground- based GPS atmospheric precipitation data , the basic configuration of atmospheric circulation and the differences and similarities in water vapor transmission characteristics among them for four heavy rain process in the Ili river valley and the north slope of Tianshan Mountains were analyzed through synthetic analysis method in this study. It is showed that:(1)200 hPa strong divergence airflow,500 hPa positive vorticity advection and southwest airflow were in favor of vertical movement development,and 700 hPa west and east airflow which provided the water vapor and instability energy,were over the rainstorm area during the heavy rainfall period,low-level convergence and high-level divergence facilitated vertical movement further strengthen which was conducive to the rainstorm occurrence;(2)compared to the low trough system ,the humidifying time of GPS was longer before the heavy rainfall occurred caused by the deep west of Siberian vortex,due to its slowly moving speed and the longer stagnation time. the stations'GPS PWV had 1-3 days humidifying process before the rainstorm occurred,appeared obvious jump during the period of precipitation,and the peak of GPS-PWV could achieve 2 times to climate average;(3)The evolution of GPS had good corresponding relation with the large-scale water vapor transport ,but the GPS high value area was not representative the precipitation area of greater value,also with the dynamic and thermodynamic condition to comprehensive judge the strength of rainstorm.%选取4次伊犁河谷、天山北坡暴雨天气过程,利用地面逐时降水、常规、NCEP/NCAR 1°×1°再分析及地基GPS遥感的大气水汽总量资料(GPS-PWV),通过合成分析方法得到暴雨期间大气环流的基本配置,阐明了伊犁河谷、天山北坡地区强降水期间环流形势及水汽输送的异同,结果表明:(1)强降水过程中暴雨区上空200 hPa强辐散气流、500 hPa槽前正涡度平流、西南气流利于垂直运动的发展,低层偏西、偏东和偏北气流为暴雨区提供水汽和不稳定能量,低层辐合、高层辐散,配合地形辐合抬升,上升运动进一步增强,造成强降水发生;(2)深厚的西西伯利亚低涡低槽系统移速缓慢,停滞时间长,造成强降水前暴雨站增湿时间更长,比较发现强降水发生前暴雨站GPS-PWV均存在1~3 d的增湿过程,暴雨期间测站GPS出现明显跃变,峰值可达到气候平均值的2倍左右;(3)GPS大气可降水量的演变与大尺度的水汽输送、聚集有较好的对应关系,但GPS高值区并不代表降水大值区,还应和动力热力等条件综合判断降水的强弱.
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