青藏高原东北侧7月少雨流型的研究  

Study on Drought Flow Pattern on the Northeast Side of Qinghai-Xizang Plateau in July

作　　者：王金花[1] 马镜娴[1] 谢金南[2] 

机构地区：[1]南京气象学院,江苏南京210044 [2]甘肃省气象局,甘肃兰州730020

出　　处：《高原气象》2004年第6期875-883,共9页Plateau Meteorology

基　　金：甘肃省十五科技攻关计划项目"西北干旱成因及其应用研究"(GS012 A45 118)资助

摘　　要：根据青藏高原东北侧9个代表站1951—2000年历年7月的降水量资料,确定了5个多、少雨年。再用NCEP/NCAR再分析格点资料,分别求出850,700,600,500,200,100,70,50和30hPa共计9个层次上多、少雨年份7月月平均合成位势高度场。计算了500hPa合成高度场与其余各个层次合成高度场流型的相似性度量以及各个层次的东亚北风指数。结果表明:20世纪80年代提出的500hPa层次上高原东北侧"西正东负"少雨流型的特征在850～70hPa整层大气中仍然存在。同时,7月少雨流型与平流层低层70,50hPa前期环流特征之间也存在联系,这些结果可供西北干旱形成研究和干旱预测业务参考。Five more and less rain years have been selected according to the data of July precipitation at nine stations on the northeast side of Qinghai-Xizang Plateau from 1951 to 2000. Then the height departures on nine levels(850, 700, 600, 500, 200, 100, 70, 50, 30 hPa) in more and less rain years are calculated by using NCEP/NCAR reanalysis grid data. In addition, we analyzed the flow pattern similarity between 500 hPa and other levels and the north wind index in East Asian on different levels. The results are as follows: 1 The character of less rain flow pattern of 'west positive and east negative' brought forward in 1980′s of last century is not only exist on 500 hPa but on the whole atmosphere(850～70 hPa). 2 The less rain flow pattern of July is related to the character of preceding circulation on 70, 50 hPa lower stratosphere. These results may provide some reference for research of the formation cause of drought in Northwest China and drought forecast operation.

关 键 词：青藏高原东北侧 少雨流型 相似性度量 东亚北风指数 

分 类 号：P468.024[天文地球—大气科学及气象学]