大气河对2013年“7.9”四川盆地持续性暴雨作用的诊断分析  

Diagnostic Analysis of the Impact of Atmospheric River in a Persistent Heavy Rainfall in Sichuan Basin

作　　者：岳俊[1] 李国平[1] 

机构地区：[1]成都信息工程学院大气科学学院,四川成都610225

出　　处：《成都信息工程学院学报》2015年第1期72-80,共9页Journal of Chengdu University of Information Technology

基　　金：国家重点基础研究发展计划(973计划)资助项目(2012CB417202);公益性行业(气象)科研专项经费资助项目(GYHY201206042;GYHY201006014)

摘　　要：2013年7月7~11日,四川盆地大部分地区出现了持续性强降雨天气（以下简称四川＂7.9＂暴雨）。此次过程的降水中心稳定少动、降水强度及总量大、持续时间长,累积降水量最高达到了1000mm以上,造成严重灾害。为分析位于孟加拉湾地区的大气河对四川＂7.9＂暴雨的影响。利用NCEP/NCAR再分析资料,通过研究孟加拉湾大气河水汽对这次暴雨的作用及影响,得到的结果表明：此次持续性暴雨过程中,孟加拉湾大气河受西太平洋副高东撤影响,并在200 h Pa和850 h Pa高低空急流的共同作用下,不断向四川地区输送水汽。这种水汽输送一直持续到11日才停止,此时降水也趋于结束。在整个暴雨过程中,850 h Pa上孟加拉湾大气河输送的水汽由于云贵高原阻挡,而绕开云贵高原在南海地区与西太副高外围的水汽以及南半球的越赤道气流汇合后,在低空急流左侧辐合气流作用下输送到四川盆地,为暴雨产生提供水汽。同时,700 h Pa上的水汽直接越过云贵高原到达四川盆地。孟加拉湾大气河的这两种输送方式为四川盆地持续性暴雨提供了充足的水汽供应。During 7-11 July 2013, in most region of Sichuan Basin persistent heavy rainfall had emerged. In this pro- cess the rainfall center is stable, and the total precipitation is huge, the rainfall intensity is heavy and lasted for a long time. The maximum precipitation reached to over 1000 mm. This process had caused serious calamities. The NCEP/ NCAR reanalysis datas are used in order to analyze the impact of the atmospheric river （AR） located in the Bay of Bengal during this process. The results showed that： in this course of persistent heavy rainfall, AR continuously transports water vapor into Sichuan Basin under the influence of West Pacific subtropical high eastward withdrawal and synergy of 200 hPa upper level jet and 850 hPa low level jet. Until 11 July, water vapor transport was stopped and the precipitation tended to cease. Throughout the course of storm, the water vapor transport at 850 hPa of AR bypassed the Yunnan-Guizhou Plateau due to the blocking effect of the Yunnan-Guizhou Plateau. These water vapor converged with the water vapor of periphery of the West Pacific subtropical high and cross-equatorial flow from southern hemisphere at the South China Sea, then transported to Sichuan Basin and provided moisture to produce heavy rainfall as the convergence on left of low level jet. Meanwhile, on 700 hPa, water vapor reached the Sichuan Basin directly without the block of Yunnan-Guizhou Plateau. The two kinds of delivery methods of AR provided ade- quate supply of water vapor for this persistent heavy rainfall in Sichuan basin.

关 键 词：气象学 持续性暴雨 诊断分析 孟加拉湾 大气河 水汽输送 

分 类 号：P458.121.1[天文地球—大气科学及气象学]