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投稿时间:2007-07-23 修订日期:2007-09-06
投稿时间:2007-07-23 修订日期:2007-09-06
中文摘要: 利用美国国家环境预报中心(NCEP)再分析资料以及山西64个测站的月降水量等资料,采用
EOF分解和合成分析方法研究了1960-2003年山西夏季降水的年际变化异常以及时空特征。利
用EOF方法分析山西夏季降水,第一类雨型是山西省夏季一致多雨型,并给出此类异常雨型
的时空分布和相应的典型年份。山西省夏季降水趋势分析表明,自1960年以来山西省夏
季降水趋于减少。从500hPa位势高度场、纬向风、850hPa风场、700hPa水汽场、海温场等物
理量场分析表明,山西夏季一致多雨年对应偏强的东亚夏季风,一般出现在La Nina事件(
冷水事件)发生的当年和El Nino事件(暖水事件)发生的来年,中高纬度地区易出现纬向
排列的+-+-环流异常纬向分布型,大陆地区为一个异常槽和两个异常脊,乌拉尔山以
东地区和鄂霍次克海是异常高压脊,而贝加尔湖地区是一个异常低压槽。山西省夏季一致少
雨年对应偏弱的东亚夏季风,一般出现在El Nino事件(暖水事件)发生的当年和La Nina事
件(冷水事件)发生的来年,与一致多雨年相反,中高纬度地区通常呈现纬向排列的-+-+环
流异常纬向分布型,大陆地区出现两个异常槽和一个异常脊。山西省夏季第一类雨型的发生
与中高纬度地区纬向排列的环流异常分布和赤道太平洋海温异常有关系。
Abstract:Using American National Centre of Environmental Prediction reanalysis
data and monthly
precipitation data at 64 observational stations of Shanxi Province,
the precipitation and temperature anomalies variation and tempora
l/spatial
distribution patterns in 1960-2003 summer was studied with EOF, wavelet analyse
s
and composite analyses methods. The first rainfall pattern over Shanxi Province
was concurrent rich/seldom rain pattern. The distinctive years were selected an
d the corresponding spatial distributions were made out. Summer precipitation tr
ends appeared the same trend pattern with the first rainfall pattern and showed
that precipitation in 43 years decreased mainly over whole Shanxi Province. With
the first rainfall pattern, analyzed were the general circulation anomalies and
meridional winds on 500hPa potential height field, 850hPa wind vector anomalous
fields, 700hPa water vapor field and sea surface temperature anomalies and so o
n. The results showed that concurrent rich rainfall pattern in Shanxi Province c
orresponded to strong East Asian summer monsoon, normally appeared at the year w
hen La Nina event was happening and El Nino event had happened during last winte
r. While at mid and high latitudes there was latitudinal+-+-anomalous circ
ulation pattern, and over Asian continent there were one trough around Baikal an
d two ridges around Ural Mountain and Okhotsk Sea respectively. Concurrent poor
rainfall pattern corresponded to weak East Asian summer monsoon, normally appear
ed at the year when El Nino event was happening and La Nina event had happened d
uring last winter. At the same time, at mid and high latitudes there was lati
tu
dinal-+-+anomalous circulation pattern, and over Asian continent there we
re two troughs and one ridge. Therefore, The first rainfall pattern in Shanxi Pr
ovince is strong related to the anomalous latitudinal wave train happened at mid
and high latitudes and SSTA over the equatorial Pacific Ocean.
keywords: precipitation anomalies East Asian summer monsoon concurrent rich rainfall pat
tern circulation anomaly
文章编号: 中图分类号: 文献标志码:
基金项目:山西省气象局开放式研究基金(SX042002),成都高原气象研究所高
原气象开放基金课题(LPM2005003),2006年国家自然科学基金课题(40675056)。
引用文本:
李智才,宋燕,朱临洪,张世英,2008.山西省夏季年际气候异常研究1.山西省一致多雨或少雨型[J].气象,34(1):86-93.
Li Zhicai,Song Yan,Zhu Linhong,Zhang Shiying,2008.On Shanxi Summer Interannual Climate Change I. Concurrent Rich/Seldom Rainfall Pattern[J].Meteor Mon,34(1):86-93.
李智才,宋燕,朱临洪,张世英,2008.山西省夏季年际气候异常研究1.山西省一致多雨或少雨型[J].气象,34(1):86-93.
Li Zhicai,Song Yan,Zhu Linhong,Zhang Shiying,2008.On Shanxi Summer Interannual Climate Change I. Concurrent Rich/Seldom Rainfall Pattern[J].Meteor Mon,34(1):86-93.