非ENSO年夏季西风带波包活动特征及对长江中下游强降水事件的影响:以1993年为例
投稿时间: 2017-10-24  最后修改时间: 2017-11-30  点此下载全文
引用本文:
摘要点击次数: 106
全文下载次数: 
作者单位E-mail
李鑫 南京信息工程大学 tlsunnylx8975@126.com 
管兆勇 南京信息工程大学 guanzy@nuist.edu.cn 
叶德超 南京信息工程大学  
中文摘要:利用Hadley中心海温资料,NCEP/NCAR再分析和中国740站逐日降水资料,运用一点滞后相关等方法,分析了非ENSO年长江流域夏季降水特征,并以1993年为例探讨了非ENSO年波包活动特征及其对长江流域夏季降水的影响。结果表明,非ENSO年长江中下游地区夏季降水年际和年代际变化明显,90年代初强降水事件多发。在1993年,波包起源于里海南侧,自西向东向长江中下游传播,为长江流域夏季降水的发生提供了必要的扰动能量积聚。通过非ENSO年和ENSO年波包活动个例的初步对比,发现非ENSO年的南支波导作用较为明显,波包主要表现为自西向东传至长江中下游地区;而作为ENSO年的1983年中,则存在一支明显的偏北波导,使波包沿着西北-东南向的路径向下游传播,最终到达长江中下游地区。这些结果有利于深刻认识非ENSO年长江流域夏季强降水事件的形成机理。
中文关键词:非ENSO年,长江流域,夏季降水,斜压波包
 
The Rossby wave packets in Non-ENSO years and their possible impacts on the severe precipitation events in the middle and lower reaches of Yangtze River: a glimpse at 1993
Abstract:Using SST data from Hadley Centre, NCEP/NCAR reanalysis along with 740-station precipitation data in China, we analyze the characteristics of Rossby wave packets and their possible impacts on severe summer precipitation events in the Yangtze River Basin in Non-ENSO year of 1993. The results show that there exist strong interannual and interdecadal variations of summer precipitation in the Yangtze River Basin for non-ENSO years. Among non-ENSO years, 1993 is a special year when the strongest flooding occurred in Yangtze river basin, which is chosen as the case for study. It is found that the wave packets in 1993 were originated from the south of Caspian Sea, propagating eastward to the middle and lower reaches of the Yangtze River. These wave packets disperse energy eastward, inducing accumulation of energy over China, facilitating the occurrence of severe summer precipitation in the Yangtze River Basin. A comparison is made for non-ENSO year 1993 and an ENSO year 1983. It is found that the route along which the wave packets propagate in Non-ENSO year 1993 locates more southern than that in ENSO year 1983. These results are helpful for us to understand the forming mechanism of severe summer rainfall events in the Yangtze River Basin.
keywords:Non-ENSO years  Yangtze River basin  summer precipitation  baroclinic wave packet
查看全文  查看/发表评论  下载PDF阅读器