四川盆地西部与东部持续性暴雨过程的对比分析  

Comparative Analysis of Persistent Heavy Rainfall Events in West and East Sichuan Basin

作　　者：李娟[1,2] 孙建华[1,2] 张元春[2] 沈新勇[1] 

机构地区：[1]南京信息工程大学气象灾害预报预警与评估协同创新中心/气象灾害教育部重点实验室,南京210044 [2]中国科学院大气物理研究所云降水物理与强风暴重点实验室,北京100029

出　　处：《高原气象》2016年第1期64-76,共13页Plateau Meteorology

基　　金：国家重点基础研究规划项目(2012CB417201;2013CB430103);国家自然科学基金项目(41205027;41375058)

摘　　要：利用常规观测资料、风云卫星资料和NCEP再分析资料等,探讨了四川盆地的盆西暴雨个例(2013年7月)和盆东暴雨个例(2007年7月)发生的环流背景条件、冷空气和水汽来源、高原对流和西南涡的特征及差异。结果表明:盆西与盆东暴雨过程相比,盆西暴雨200 hPa急流位置更偏北,西风槽位置偏西,副热带高压的位置偏北、强度偏强,西南涡位置也较偏西南;盆西暴雨过程对流层中层有来自青藏高原以西的中亚地区和青藏高原西部的冷空气,低层水汽输送以来自孟加拉湾的西南气流为主,盆东暴雨过程对流层中层只在前期有来自中高纬度的冷空气,中后期在对流层中层无中高纬度地区冷空气影响,主要以来自孟加拉湾和青藏高原南侧的偏西气流为主,低层水汽输送以来自南海的东南气流为主;盆西和盆东暴雨过程的对流活动都有明显的日变化,对流下午在川西高原发展,后半夜至早晨在盆地发展,区别在于盆西暴雨过程有川西高原对流东移与盆地对流合并发展的过程,而盆东暴雨过程中川西高原对流在东移过程中减弱,无与盆东对流合并发展的过程。Based on the conventional observation data,reanalysis data from NCEP/NCAR,satellite data and so on,the characteristics of circulation background,source of cold air and water vapor,convective systems over the Qinghai-Xizang Plateau and southwest vortex are analyzed on the two persistent heavy rainfall in western Sichuan basin and eastern Sichuan basin.The results show that in the western basin event,the location of high-level jet on 200 hPa was norther,the subtropical high was northeaster,the westerly trough and southwest vortex were westerner than the eastern basin event;cold air in the middle troposphere came from central Asia and western edge of the Qinghai-Xizang Plateau,water vapor in low level was transported by southwest airflow from the bay of Bengal in the western basin event;cold air came from mid-latitude at the early stage of event,while during the later period,the westerly flow in the middle troposphere mainly came from Bengal and southern QinghaiXizang Plateau,water vapor in low level was transported by southeast airflow that from South China Sea in the eastern basin event.The convective activities in western Sichuan plateau and basin have significant diurnal variation：from the afternoon to early evening in western Sichuan plateau,from the late evening to the next early morning in Sichuan basin,the difference is the eastward propagation of convective system from the edge of the Qinghai-Xizang Plateau merged with the clusters over western basin in the western basin event,but for the eastern basin event,convective system weakened as it moved eastward,there was no merging process.

关 键 词：持续性暴雨 多尺度特征 水汽输送 高原对流 西南涡 

分 类 号：P466[天文地球—大气科学及气象学]