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1.
用主振荡型( P O P)方法分析了热带洋区月平均海表温度异常( S S T A)。结果表明,最重要的 4 个传播型 P O P对与 El Nino/ La Nina 事件关系密切,说明这类事件具有复杂的时空结构。在此基础上,给出了一个能定量地综合多个传播型 P O P对作用的 P O P中性预测方案。非独立样本和独立样本试验表明,它具有 4 个月的预测时效,且其预测能力在 S S T 强异常的 El Nino、 La Nina 事件阶段强于弱异常的非 El Nino/ La Nina 事件阶段。  相似文献   

2.
热带西太平洋海表温度长期变化的特殊性   总被引:5,自引:1,他引:4  
揭示了50年代以来热带三大洋海表温度(SST)长期变化的两个基本构成(线性增温及El Nino-La Nina振荡),并比较了它们在三大洋中的典型程度。在此基础上重点分析了热带太平洋西、中、东部SST长期变化的差异,指出热带西太平洋SST长期变化中El Nino-La Nina振荡相对较弱,线性增温趋势被年代际强弱振荡代替。  相似文献   

3.
西太平洋暖池次表层海温一场与ENSO关系的CGCM模拟结果   总被引:19,自引:4,他引:15  
全球大气与热带太平洋相耦合的数值模式(CGCM) 很好地模拟了ENSO ( 厄尔尼诺和拉尼娜) 型海表水温(SST) 异常, 进一步分析多年的模式积分结果, 清楚地表明赤道中东太平洋SST 异常与西太平洋暖池次表层( 深100 ~200 m) 的海温异常有密切的关系。在El Nino 事件发生之前的半年到一年左右, 西太平洋暖池次表层海温有明显正异常,并向东传播; 而在La Nina 发生之前的半年到一年左右, 暖池次表层海温有明显负异常, 并向东传播。因此, 西太平洋暖池次表层海温异常及其东传对El Nino (La Nina) 的发生有极重要作用。  相似文献   

4.
云南雨季早迟的气候特征分析   总被引:12,自引:0,他引:12  
刘瑜 《气象》2000,26(7):45-49
分析了100hPa南亚高压的变化、500hPa位势高度距平特征与云南雨季开始期早晚的对应关系,归纳总结了El Nino和La Nina事件与西南季风建立、雨季迟早的联系,提出了云南雨季开始早迟的预报思路。  相似文献   

5.
青藏高原臭氧的ENSO   总被引:3,自引:0,他引:3  
通过对臭氧卫星观测资料及大气环流资料的分析,研究了青藏高原上空臭氧年际变化中的 ENSO信号,并与同纬度无山区及赤道地区进行比较。研究指出:在 E1 Nino年(SOI指数为负)青藏高原臭氧总量增加,在 La Nina年(SOI指数为正)青藏高原臭氧总量减小。本文同时讨论了与ENSO事件有关的大气环流物质输送。  相似文献   

6.
热带大气季节内振荡激发El Nino的机制   总被引:15,自引:1,他引:15  
资料分析了表明,热带大气季节内振荡同El Nino发生有密切的关系。在El Nino事件发生之前,热带大气(尤其是赤道西太平洋地区)季节内振荡异常加强;伴随着El Nino的发生,热带大气季节内振荡动能明显增加。简单海-气耦合模式的分析表明,只有在年陵时间尺度大气外强迫作用下,海-气系统才可以产生类似ENSO模的耦合波。资料和理论模式分析和结果相结合,说明热带大气季节内振荡激发El Nino的机制  相似文献   

7.
ENSO事件对冬季北半球太平洋风暴轴维持的影响   总被引:12,自引:3,他引:9  
利用欧洲中期天气预报中心(ECMWF)每日客观分析资料及美国大气研究中心(NCAR)再分析资料研究ENSO事件对简报北半球太平洋风暴轴维持的影响,结果表明,El、Nino(La Nina)年,风暴轴区域斜压性强(弱),风暴轴位置向东(西)扩展(收缩)且强度强(弱),与风暴轴发展有关的涡动热量通量和运量通量也同时增强(减弱),由此揭示出ENSO事件对太平洋风暴轴的维持和发展有重要影响.  相似文献   

8.
El Nino对云南初夏降水的影响   总被引:7,自引:4,他引:7  
利用云南初夏5-6月的降水资料,全球月平均海温资料及热带OLR资料,研究了云南初夏5-6月降水对海气相互作用特别是El Nino的响应,发现云南初夏降水与赤道东太平洋海温变化以及南海对流活动有密切关系。  相似文献   

9.
采用COADS的月平均海平面温度跨平(SSTA)资料,建立了预报热带印度洋-太平洋SSTA的线性转置模型(LIM)。经检验,对于非独立和独立样本,预报的均方根误差分别在12个月和10个月预报时效内小于SSTA的均方差,相对误差在5个月预报时效内都小于50%。在E1Nino和La Nina时段效果优于其他时段,其中La Nina时段又更好些。对同一地区的SSTA,LIM预报优于自回归模型预报、奇异谱  相似文献   

10.
根据1800-1989年(110年)的资料,分析研究了新加坡地区月平均和年平均降雨量的一些特征。主要结论是:新加坡年平均降雨量存在准2-6年和18年的周期振荡;亚洲季风以及ENSO对新加坡降雨量有明显的影响。新加坡年雨量的谷值出现在西南季风期而峰值在东北季风期。在El Nino年,新加坡降雨量多为负距平;而在反El Nino年,新加坡降雨量多为正距平。  相似文献   

11.
Experimental predictions with a hybrid coupled ocean-atmosphere model(L9R15 AGCM-ZCocean model)were performed for the 1986/87 El Nino event and the 1988/89 La Nina event withand without the Tibetan Plateau respectively(called TP FORC and NTP FORC hereinafter).Comparison shows that,to some extent,the existence of the Tibetan Plateau orography weakensor restrains(strengthens or facilitates)the formation of the anomalous circulation of Asianmonsoon during El Nino(La Nina)period.Opposite results are found in the uncoupled AGCMsimulation.  相似文献   

12.
A hybrid coupled ocean-atmosphere model is designed,which consists of a global atmosphericgeneral circulation model(L9R15 AGCM)and a simple ocean model(ZC ocean model over tropicalPacific).Using the model,experimental predictions are performed for the 1986/87 El Nino eventand the 1988/89 La Nina event with and without the Tibetan Plateau respectively(called TPFORC and NTP FORC hereinafter).It is found as follows:(1)The coupled system cansuccessfully predict the El Nino or La Nina event even if the Tibetan Plateau orography is notincluded in the model.The patterns of SSTA and wind anomalies in the model without the TibetanPlateau are similar to those with the Tibetan Plateau,which further verifies the fact that ENSOprocess is mainly caused by the air-sea interaction in tropical Pacific.(2)However.the existenceof the Tibetan Plateau exerts its influences on the intensity and duration of El Nino(or La Nina).It is unfavorable to the development and maintenance of westerly anomalies,so to some extent,restrains the development of El Nino,but favors the development of La Nina.(3)Effects of theTibetan Plateau orography on the wind anomalies in the coupled system are different from those inuncoupled AGCM simulation.  相似文献   

13.
A hybrid coupled ocean-atmosphere model is designed,which consists of a global atmospheric general circulation model(L9R15 AGCM)and a simple ocean model(ZC ocean model over tropical Pacific).Using the model,experimental predictions are performed for the 1986/87 El Nino event and the 1988/89 La Nina event with and without the Tibetan Plateau respectively(called TP FORC and NTP FORC hereinafter).It is found as follows:(1)The coupled system can successfully predict the El Nino or La Nina event even if the Tibetan Plateau orography is not included in the model.The patterns of SSTA and wind anomalies in the model without the Tibetan Plateau are similar to those with the Tibetan Plateau,which further verifies the fact that ENSO process is mainly caused by the air-sea interaction in tropical Pacific.(2)However.the existence of the Tibetan Plateau exerts its influences on the intensity and duration of El Nino(or La Nina).It is unfavorable to the development and maintenance of westerly anomalies,so to some extent,restrains the development of El Nino,but favors the development of La Nina.(3)Effects of the Tibetan Plateau orography on the wind anomalies in the coupled system are different from those inuncoupled AGCM simulation.  相似文献   

14.
厄尔尼诺和反厄尔尼诺事件与西北太平洋台风活动   总被引:42,自引:12,他引:42  
用统计相关和典型年合成方法分析了厄尔尼诺和反厄尔尼诺事件与西北太平洋台风活动的关系,指出厄尔尼诺年台风活动减少,反厄尔尼诺年台风活动增加,而且台风活动与厄尔尼诺、反厄尔尼诺事件起始和终止时间、强度、台风生成区域有关。利用厄尔尼诺和反厄尔尼诺年台风活动频数的统计特征,及台风频数与海温等要素的时滞相关关系,为台风频数的预测提供了有益的信息。还应用奇异值分解方法,分析了高度场和海温场的相关关系。结果表明,厄尔尼诺年海气耦合作用将造成不利于台风发展的环流条件,因此台风偏少,反厄尔尼诺年则出现相反的情况。  相似文献   

15.
赤道太平洋海域海温异常事件包括厄尔尼诺 (EL- Nino)和拉尼娜 (L a- Nina)现象。通过对赤道东中太平洋特定区域海温指数的统计分析 ,确定厄尔尼诺和拉尼娜出现的诊断指标 ,分析了厄尔尼诺和拉尼娜的出现周期 ,在此基础上分析了厄尔尼诺与拉尼娜对广西气候变化的一些主要影响  相似文献   

16.
ENSO事件对川西高原区的气候影响   总被引:4,自引:0,他引:4       下载免费PDF全文
根据1951-2010年川西高原区7个气象站降水资料和气温资料以及60 a间发生的厄尔尼诺(El Ni?o)/拉尼娜(La Ni?a)事件,分析降水量、气温与El Ni?o /La Ni?a事件之间的关系,研究El Ni?o/La Ni?a事件对川西高原区气候的影响。结果表明:1951年以来川西高原区年降水量变化不大,呈现微弱的增加趋势,El Ni?o/La Ni?a 事件的发生对川西高原区年平均降水量有影响,El Ni?o事件影响下的年平均降水量减少,La Ni?a事件影响下的年平均降水量增加;El Ni?o年降水量低于正常年降水量39.14 mm,拉尼娜年降水量高于正常年降水量22.56 mm。1951年以来川西高原区年平均气温呈现微弱的波动上升趋势,川西高原区年平均气温与ENSO事件等级之间的相关性不显著。  相似文献   

17.
根据1967-2016年揭阳市4个国家气象站(揭阳市区、揭西、普宁、惠来)的观测资料以及Nino3+4区的海温指数(ONI),分析了揭阳市降水量、暴雨日数与厄尔尼诺/拉尼娜事件的关系。结果表明,50a来揭阳市的年降水量呈现出年际和年代际波动起伏的特点。在厄尔尼诺/拉尼娜事件发生时,揭阳春季降水主要表现为偏多/偏少,秋季降水主要表现为偏少/偏多,秋季暴雨日数主要表现为偏少或偏多;冬季暴雨只出现在厄尔尼诺事件或拉尼娜事件发生的年份。  相似文献   

18.
The numerical simulations,hindcasts and verifications of the tropical Pacific sea surface temperature anomaly(SSTA) have been conducted by using a dynamical tropical Pacific ocean-atmosphere coupled model named NCCo.The results showed that the model had performed reasonable simulations of the major El Nino episodes in the history,and the model forecast skill in 1990s had been significantly improved.NCCo model has been used to predict the tropical Pacific SSTA since January 1997.The comparisons between predictions and observations indicated that the occurrence,evolution and ending of the 1997-1998 El Nino episode have been predicted fairly well by using this model.Also,the La Nina episode that began in the autumn of 1998 and the developing tendency of the tropical Pacific SSTA during the year 1999 have been predictedsuccessfully.The forecast skills of NCCo model during the 1997-1999 El Nino and La Nina events are above 0.5 at 0-14 lead months.  相似文献   

19.
2°×2° mean monthly COADS grid data in 1974 and 1987 of E1 Nino and La Nina years are used to compute thesensible and latent heat fluxes,the net longwave radiation,the incident solar radiation and heat budget on the tropicalPacific surface(30°S—30°N).The difference of the heat budget between El Nino and La Nina mainly occurred on theequatorial ocean surface,especially the water area west of Ecuador and Peru.During El Nino,the sensible and latentheat exchange increased,the net longwave radiation and incident solar radiation decreased and the net gain(loss) of heatreduced(increased) on the ocean surface.During La Nina,the circumstances were opposite.Finally an ideal model ofair-sea heat exchange mechanism for the El Nino-La Nina cycle is summarized. Key words:El Nino,La Nina,air-sea heat exchange,COADS grid data  相似文献   

20.
NUMERICAL SIMULATION OF LAG INFLUENCE OF ENSO ON EAST-ASIAN MONSOON   总被引:2,自引:0,他引:2  
By prescribing sea surface temperature anomalies(SSTAs)over eastern equatorial Pacific inJanuary—March,the lag influence of ENSO(El Nino and La Nina)on monsoon over East Asiahas been studied.The results suggest that,due to the excitation of atmospheric low-frequencyoscillation by the SSTA,ENSO has significant lag influence on the monsoon over East Asia.During the summer after E1 Nino,the subtropical high over western Pacific is intensified andshows the northward and westward displacement,meanwhile,the rainfall over East China isbelow normal,especially in North China:during the winter after E1 Nino,both the Asian troughand the winter monsoon over East Asia are strengthened.During the summer after La Nina,theanomalous subtropical high prevails over the lower reaches of Yangtze(Changjiang)River,therainfall between Yangtze and Huaihe Rivers is below normal:during the winter after La Nina,both the Asian trough and the winter monsoon over East Asia are weaker.Compared with LaNina,the effect of El Nino is stronger,but it is not always opposite to the one of La Nina.  相似文献   

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