E1 Nio phenomenon in simple ocean data assimilation data     

GUI Maochang  *  WU Lingjuan  . Institute of Oceanology  Chinese Academy of Sciences  Qingdao  China. Laboratory of Numerical Modeling for Atmospheric Sciences  Geophysical Fluid Dynamics  Institute of Atmospheric Physics  Chine-se Academy of Sciences  Beijing  China. Graduate School  Chinese Academy of Sciences  Beijing  China 《海洋学报(英文版)》2005,(4)

1 IntroductionIt is well known that interaction between the trop-ical ocean and atmosphere produces the largest inter-annual climate signal, El Nino-Southern Oscillation(ENSO). In past decades many efforts have been madein understanding and predicting ENSO: such as the hy-pothesis of Bjerknes (1969) that ENSO arises as aself-sustained cycle in which SSTA in the Pacific O-cean causes the trade winds to strengthen or slackenand that this in turn drives the ocean circulation changesthat …  相似文献   

Oceanographic influences on seabirds and cetaceans of the eastern tropical Pacific: A review     

Lisa T. Ballance  Robert L. Pitman  Paul C. Fiedler 《Progress in Oceanography》2006,69(2-4):360

This paper is part of a comprehensive review of the oceanography of the eastern tropical Pacific, the oceanic region centered on the eastern Pacific warm pool, but also including the equatorial cold tongue and equatorial current system, and summarizes what is known about oceanographic influences on seabirds and cetaceans there. The eastern tropical Pacific supports on the order of 50 species of seabirds and 30 species of cetaceans as regular residents; these include four endemic species, the world’s largest populations for several others, three endemic sub-species, and a multi-species community that is relatively unique to this ecosystem. Three of the meso-scale physical features of the region are particularly significant to seabirds and cetaceans: the Costa Rica Dome for blue whales and short-beaked common dolphins, the Equatorial Front for planktivorous seabirds, and the countercurrent thermocline ridge for flocking seabirds that associate with mixed-species schools of spotted and spinner dolphins and yellowfin tuna. A few qualitative studies of meso- to macro-scale distribution patterns have indicated that some seabirds and cetaceans have species-specific preferences for surface currents. More common are associations with distinct water masses; these relationships have been quantified for a number of species using several different analytical methods. The mechanisms underlying tropical species–habitat relationships are not well understood, in contrast to a number of higher-latitude systems. This may be due to the fact that physical variables have been used as proxies for prey abundance and distribution in species–habitat research in the eastern tropical Pacific.Though seasonal and interannual patterns tend to be complex, species–habitat relationships appear to remain relatively stable over time, and distribution patterns co-vary with patterns of preferred habitat for a number of species. The interactions between seasonal and interannual variation in oceanographic conditions with seasonal patterns in the biology of seabirds and cetaceans may account for some of the complexity in species–habitat relationship patterns.Little work has been done to investigate effects of El Niño-Southern Oscillation cycles on cetaceans, and results of the few studies focusing on oceanic seabirds are complex and not easy to interpret. Although much has been made of the detrimental effects of El Niño events on apex predators, more research is needed to understand the magnitude, and even direction, of these effects on seabirds and cetaceans in space and time.  相似文献   

热带地区积云对流的长期变化特征     

温之平  梁必骐 《热带海洋学报》1996,(3)

使用１９７９年１月至１９８４年１２月向外长波辐射（ＯＬＲ）资料，对热带地区积云对流的长期变化特征进行了研究。结果表明：热带地区积云对流活动存在显著的季节变化，冬季积云对流区主要是东西向，位于南印度洋和西太平洋的近赤道地区；夏季则北移至北印度洋和菲律宾附近的西太平洋地区。低纬地区积云对流活动存在明显的季节性位移，北印度洋地区的积云对流活动主要集中在５—１０月，７—８月位置最北；北半球热带西太平洋地区的积云对流活动则主要集中在６—１１月，８—９月位置最北。标准差分析表明，冬季北半球热带西太平洋、赤道中太平洋及热带印度洋东部地区积云对流的年际变化最明显。经验正交函数（ＥＯＦ）分析的主要空间型反映了赤道中太平洋、热带西太平洋、阿拉伯海和副热带西太平洋地区的积云对流活动存在一定的关系。结合遥相关计算还表明秋云对流存在４种遥相关型，即２种东西向偶极型涛动型、西太平洋型和北印度洋型。  相似文献   

Impact of Two "El Niño" Events of Different Intensity on the Hypoxic Soft Bottom Macrobenthos off the Central Peruvian wast     

Juan  Tarazona  Wolf E.  Arntz Elba  Canahuire 《Marine Ecology》1996,17(1-3):425-446

Abstract. Monthly changes in the community structure of hypoxic soft-bottom macrobenthos have been studied at a station at 34 m depth in Ancón Bay (Peru) before and during two El Niño (EN) events. Of these events, 1982-83 is considered the strongest, and 1991–93 one of the most prolonged in the 20th century. On the oceanographic scale, EN 1982–83 ranges as "very strong", whereas EN 1991–93 ranges as "moderate".
The thermal anomalies at the station during EN 1982–83 (+ 7.8 °C) were almost twice those of EN 1991–93 (+ 4.1 °C). However, the community changes were not in all cases proportional to the extent of warming. Species numbers increased in a similar way (up to 24 species from near zero in each of the two events), but maximum faunal density was five times higher, and mean biomass was twice as high in 1982–83 compared with the event a decade later. Species diversity was slightly higher during EN 1982–83, whereas successional and trophic changes occurred on a broader scale during EN 1991–93. On the whole, the impact of the long-lasting event on the small soft-bottom macrofauna was not much weaker than that of the exceptionally strong event.
The authors discuss the mechanisms which may be responsible for the differences and similarities encountered in the benthic community dynamics during these two events. Both in the unusually strong and the unusually long EN, the community revealed a pattern of early biological response several months ahead of the onset of local warming which marks the official begin of EN. The question is addressed to what extent the increase of certain parameters in the benthic community could be used for predictive purposes.  相似文献   

太阳黑子、厄尔尼诺及西北太平洋热带气旋的活动   总被引：4，自引：0，他引：4  

毛祖松  金德山 《海洋预报》1996,(4)

本文用１９００～１９９４年的资料，以统计分析的方法，对太阳黑子，厄尔尼诺及西北太平洋热带气旋活动的相互关系，进行了初步探讨，归纳出几点有参考价值的结论  相似文献   

信风张弛对赤道东、西太平洋斜压扰动的影响研究          下载免费PDF全文

林永辉  王柏忠 《海洋学报》2003,25(5):29-37

利用一个斜压两层海洋模式解析地研究了赤道东、西太平洋对信风张弛的响应特征.研究表明:当赤道上空偏东信风张弛或转为西风时,由于打破了海洋原来的平衡关系,结果在赤道东、西太平洋的温跃层附近产生了扰动并开始传播.西太平洋温跃层附近的扰动向东传播的速度远大于东太平洋扰动向西传播的速度,而且与东太平洋温跃层扰动向西传播的狭窄范围和小振幅相比,西太平洋温跃层扰动向东传播的范围和强度均很大.这与最近几次强厄尔尼诺增暖事件暖水从赤道西太平洋向赤道中、东太平洋的迅速传播特征是一致的.  相似文献   

基于PMIP2气候模式模拟的中全新世北大西洋涛动   总被引：1，自引：0，他引：1  

张肖剑  靳立亚  俞飞  王志远 《海洋学报》2010,32(4):41-50

根据PMIP2中的4个海气耦合模式对中全新世气候的模拟结果,利用现代和中全新世两个时间段的冬季海平面气压场(SLP),分析了北大西洋海平面气压的变化情况并计算了这两个时间段的北大西洋涛动(NAO)指数。结果表明,中全新世亚速尔高压加强,冰岛低压加深,南北气压差增加,NAO强度显著增强。对中全新世北大西洋地区SLP进行经验正交函数(EOF)分析显示,4个模式均能捕捉到了NAO的主要结构。中全新世NAO处于正位相的时间较现代提高了10%~30%,其中MIROC3.2提高了29.3%;虽然NAO指数振幅变化不大,但还是能显示中全新世NAO显著强于现代,这与地质资料恢复的结果相一致。对NAO指数的多窗谱分析显示,现代NAO指数存在3~5 a的准周期变化,中全新世NAO指数存在3 a的准周期变化。NAO对中全新世亚洲地区冬季增温有重要影响。北大西洋地区中纬度海面温度(SST)的增温可能是导致中全新世NAO强度增强的一个重要因素。  相似文献   

利用卫星测高技术监测厄尔尼诺和拉尼娜现象   总被引：2，自引：0，他引：2  

赵小阳  李建成  王正涛  金涛勇 《海洋测绘》2007,27(1):41-44

利用美国宇航局和法国空间局联合公布的T／P数据（1993-2000年）和Jason-1数据（2002—2006年），由共线法计算了热带太平洋地区海平面高度的变化。根据T／P和Jason-1数据计算的海面月变化异常图，分别研究了和分析了1997-1998年的厄尔尼诺和拉尼娜现象、2002-2003年厄尔尼诺现象的变化发展过程。  相似文献   

El Niño对东亚气候年际异常影响的数值模拟   总被引：3，自引：0，他引：3  

孙旭光  杨修群 《海洋学报》2007,29(5):21-30

根据1949~1998年期间8次显著El Niño事件合成的24个月年际海温异常(SSTAs)和气候平均的海温(SST),利用CCM3分别进行了3个包含10次积分的集合试验,即控制试验(CTRL),热带太平洋海洋全球大气试验(TOGA)以及整个太平洋海洋全球大气试验(TOGA-NP),通过对比分析这3个试验之间的集合模拟结果,揭示了在El Niño不同演变阶段东亚气候年际异常响应结构以及北太平洋年际SSTAs在此过程中的调制作用.结果表明:El Niño发展阶段夏季,东亚地区大气环流异常呈显著的负PJ波列,副热带高压减弱、偏东,东亚夏季风增强,东北和江淮流域降水偏多,华北和长江流域及其以南地区降水偏少;El Niño成熟阶段冬季,东亚大槽加强,东亚北部冬季风加强,西太平洋副热带地区低层有显著的反气旋式异常风场,华南地区降水显著增多;El Niño衰亡阶段夏季东亚气候年际异常型与其发展阶段夏季几乎相反.同时,北太平洋年际SSTAs对El Niño影响东亚气候年际异常有一定的调制作用,使模拟的我国降水异常分布更符合观测.  相似文献   

西太平洋暖池变异及其对西太平洋次表层海温场的影响   总被引：9，自引：0，他引：9  

陈锦年  何宜军  孙树远  许兰英  宋贵霆  张艳慧 《海洋学报》2002,24(3):35-44

应用热带太平洋上层XBT温度资料,分析研究了西太平洋暖池区(0°～16°N,125°～145°E)上层海洋的变化特征以及与西太平洋次表层海温场之间的关系.研究表明,西太平洋暖池区的垂向温度存在显著的年际变化,尤其在次表层(120～200m)的变化最为明显.西太平洋暖池区的次表层冷暖信号明显早于西太平洋次表层的海温异常.分析发现,西太平洋暖池区的海温异常是导致整个西太平洋次表层海温场变异的关键区,当西太平洋暖池区的次表层冷暖信号加强时,3～4个月后西太平洋海温场出现大范围的冷暖异常.  相似文献