河西走廊中部一次强降水过程的多普勒雷达资料分析  

Analysis on the Doppler Radar Data of a Heavy Rainfall Process in the Central Hexi Corridor

作　　者：付双喜[1,2] 张鸿发[3] 楚荣忠[3] 

机构地区：[1]甘肃省人工影响天气办公室,甘肃兰州730020 [2]甘肃省干旱气候变化与减灾重点实验室,甘肃兰州730020 [3]中国科学院寒区旱区环境与工程研究所,甘肃兰州730000

出　　处：《干旱区研究》2009年第5期656-663,共8页Arid Zone Research

基　　金：国家自然科学基金重点项目(40533015);国家自然科学基金项目(40575008);中国气象局气象新技术推广项目"冰雹云CINRAD/CC雷达预警及防雹作业指挥系统技术推广(CMATG2009MS38)"共同资助

摘　　要：利用张掖C INRAD/CC多普勒雷达资料,结合自动站逐时雨量、DEM和常规气象观测资料,对2005年6月30日～7月2日发生在河西走廊的一次地形强降水过程进行分析。结果表明：这次强降水是一次积层混合云降水,具有典型地形影响降水的回波特征;积状云主要由祁连山地形影响产生对流泡发展而成,降水主要集中在祁连山北坡和龙首山脉的西南侧;速度场上反映出低层冷平流、中高层暖平流的流场,致使这次降水持续发展,回波处于稳定;中低层负速度区面积增大,正速度区面积缩小,气流场为大尺度的辐合与暖平流叠加而成,为后期降水的水汽输送和加强提供了动力和热力条件;风廓线产品（VWP）上可以确定垂直风切变、冷暖平流及回波高度,进而推断降水的强度及生消;特殊的口袋状地形是造成局地强降水机理的主要原因。This paper analyzed a heavy rainfall process. Occurred in the central Hexi Corridor from 30 June to 2 July 2005 using the CINRAD/CC Doppler radar data, hourly rainfall data derived by the automatic meteorological stations, and DEM and conventional meteorological observation data in Zhangye. The results show that the heavy rainfall was caused by a plot of mixing cumulostratus with the typical echo characteristics of rainfall ; the cumuliform cloud was mainly generated from the development of convection bubble under the effect of terrain in the Qilian Mountains, and the rainfall occurred mainly in the northern slope of the Qilian Mountains and the southwest piedmont of the Longshou Mountains; the velocity field was reflected by the low-level cold advection and the high-level warm advection, which resulted in the continuous development of rainfall and the stabilization of echo; the area of low-level negative speed zone was enlarged but that of positive one was reduced, the flow field was superposed by the large-scale convergence and the warm advection, which provided the dynamic and thermal conditions for the successional water vapor transport and rainfall; VWP could be used to identify the vertical wind shear, stratospheric height and echo, and then to infer the intensity, occurrence and termination of rainfall; the special pocket-shaped terrain was the main mechanism causing the heavy rainfall.

关 键 词：多普勒雷达 降水过程 气流场 水汽输送 张掖 河西走廊 

分 类 号：P458.121.1[天文地球—大气科学及气象学]