河南一次特大暴雨过程的天气学分析

利用NCEP再分析资料，对2005年7月20-22日河南西部特大暴雨的成因进行了诊断分析。结果表明：台风低压倒槽外围的东南气流和副高西南侧的东南气流合并，形成一支较强盛的东南气流带是本次特大暴雨的水汽来源；辐合线和地形的作用是本次特大暴雨的触发机制；特大暴雨中心附近存在低空的气旋辐合、高空的反气旋辐散，且在特大暴雨发生发展时，高空的反气旋辐散作用起主导作用，是特大暴雨发展和维持的依据；在前期有东南急流存在的情况下，东风分量和南风分量明显减弱的时刻．是强降水发生的时刻。

Synoptic Analysis of the Super Rainstorm Process in Henan

Using the NCEP reanalysis data,we make this analysis to find out the cause of the formation of the super rainstorm occurred in the western Henan from July 20 to 22 of 2005.The results show that the vapor source of this severe rainfall is a relative puissant southeast airflow,which is formed by the combination with the southeast air at the boundary of the typhoon inverted trough and the southwest side of the subtropical high.The trigger mechanism is the effect of the convergence line and the orographic influ...