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1.
应用TAO(Tropical Atmosphere Ocean project)热带太平洋实测海温和风场资料,分析研究了2010/2011年La Nia事件的变化特征,讨论了此次过程中赤道太平洋次表层异常海温的变化特征及其传播过程,以及上层海温场的异常变化机理。结果表明,2010/2011年的La Nia事件与传统事件不同,是一次明显的中部型La Nia事件(简称CPP La Nia),其爆发过程主要存在两个不同机制的响应过程:一是西太平洋暖池(WPWP)区域次表层异常冷海温通过赤道潜流的作用沿温跃层东传,导致赤道东太平洋上层海洋温度场出现异常降温:二是赤道中东太平洋出现强的距平东风,通过上升流作用,导致冷海温上传影响中太平洋上层异常海温场。前者是导致La Nia事件的必要条件,后者则是形成此次中部型La Nia事件的关键过程。由分析结果还表明,日界线以东赤道太平洋纬向风变化对中西太平洋上层海温场变化有重要影响,是导致此次中部型事件爆发的重要机制。文章进一步分析了此次中部型La Nia事件过程中热带垂直环流的变化,结果表明经向和纬向大气环流都表现出明显的异常。 相似文献
2.
Seasonal Variability of Near-Surface Heat Budget of Selected Oceanic Areas in the North Tropical Indian Ocean 总被引：1，自引：0，他引：1
The results obtained from an Ocean General Circulation Model (OGCM), the Modular Ocean Model 2.2, forced with the National
Center for Environmental Prediction/National Center for Atmospheric Research reanalysis data, and observational data have
been utilized to document the climatological seasonal cycle of the upper ocean response in the Tropical Indian Ocean. We address
the various roles played by the net surface heat flux and the local and remote ocean dynamics for the seasonal variation of
near-surface heat budget in the Tropical Indian Ocean. The investigation is based in seven selected boxes in the Arabian Sea,
Bay of Bengal and the Equatorial Indian Ocean. The changes of basin-wide heat budget of ocean process in the Arabian Sea and
the Western Equatorial Indian Ocean show an annual cycle, whereas those in the Bay of Bengal and the Eastern Equatorial Indian
Ocean show a semi-annual cycle. The time tendency of heat budget in the Arabian Sea depends on both the net surface heat flux
and ocean dynamics while on the other hand, that in the Bay of Bengal depends mainly on the net surface flux. However, it
has been found that the changes of heat budget are very different between western and eastern regional sea areas in the Arabian
Sea and the Bay of Bengal, respectively. This difference depends on seasonal variations of the different local wind forcing
and the different ocean dynamics associated with ocean eddies and Kelvin and Rossby waves in each regional sea areas. We also
discuss the comparison and the connection for the seasonal variation of near-surface heat budget among their regional sea
areas.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
用赤道太平洋长达21a的温度资料以及经验正交函数(EOF)分析方法,讨论了在5°S-5°N平均纬向垂直剖面上赤道太平洋垂向温度梯度距平的时空变化,得到了一些有意义的结果。赤道太平洋垂向温度梯度距平EOF分析第1模态的正/负位相反映了El Nino/La Nina发生前赤道太平洋温跃层的分布,第2模态的正/负位相反映了El Nino/La Nina鼎盛以及开始衰减时赤道太平洋温跃层的分布。根据我们对赤道太平洋温跃层核心位置的定义,在El Nino向LaNina转换的过程中,赤道东太平洋温跃层上升了30-40m,而赤道中太平洋温跃层先是上升了40-50m,然后又下降了40-50m,赤道西太平洋温跃层下降了90m;随着赤道西太平洋暖水的堆积以及东移,温跃层首先在赤道西太平洋加深,El Nino发生前赤道中东太平洋温跃层开始加深,El Nino达到鼎盛时赤道西太平洋温跃层抬升,而赤道中东太平洋温跃层加深;赤道太平洋垂向温度梯度距平EOF分析第1特征向量的时间系数与Nino3区的SST距平有非常好的相关,并且超前于Nino3区的SST距平,超前3个月的相关系数高达0.7017,超前6个月的相关系数高达0.6467,因此可以用该量来预测Nino3区的SST距平。 相似文献
4.
依托中国“大洋一号”第20和第21调查航次,分析测定了东、西赤道太平洋4个站位的颗粒态生物硅浓度及其粒级结构。结果显示赤道太平洋采样站各层位颗粒态生物硅(PBSi)总浓度分布范围为5~65 nmol/dm3,东赤道太平洋的调查站位颗粒态生物硅的总浓度平均值达46 nmol/dm3,是西赤道太平洋的近3倍。PBSi的粒径结果显示在东赤道太平洋调查站位0.8~20 μm粒径颗粒是PBSi的主要来源,其平均贡献率高达64%;而在西赤道太平洋2种粒径的生物硅贡献率相当。营养盐分布对PBSi的浓度及粒径分布有显著的影响,并在一定程度上控制了“硅质泵”的组成结构,是控制大洋生物泵运转的重要因素。 相似文献
5.
The circulation of the eastern tropical Pacific: A review 总被引：5，自引：9，他引：5
During the 1950s and 1960s, an extensive field study and interpretive effort was made by researchers, primarily at the Scripps Institution of Oceanography, to sample and understand the physical oceanography of the eastern tropical Pacific. That work was inspired by the valuable fisheries of the region, the recent discovery of the equatorial undercurrent, and the growing realization of the importance of the El Niño phenomenon. Here we review what was learned in that effort, and integrate those findings with work published since then as well as additional diagnoses based on modern data sets.Unlike the central Pacific, where the winds are nearly zonal and the ocean properties and circulation are nearly independent of longitude, the eastern tropical Pacific is distinguished by wind forcing that is strongly influenced by the topography of the American continent. Its circulation is characterized by short zonal scales, permanent eddies and significant off-equatorial upwelling. Notably, the Costa Rica Dome and a thermocline bowl to its northwest are due to winds blowing through gaps in the Central American cordillera, which imprint their signatures on the ocean through linear Sverdrup dynamics. Strong annual modulation of the gap winds and the meridional oscillation of the Intertropical Convergence Zone generates a Rossby wave, superimposed on the direct forcing, that results in a southwestward-propagating annual thermocline signal accounting for major features of observed thermocline depth variations, including that of the Costa Rica Dome, the Tehuantepec bowl, and the ridge–trough system of the North Equatorial Countercurrent (NECC). Interannual variability of sea surface temperature (SST) and altimetric sea surface height signals suggests that the strengthening of the NECC observed in the central Pacific during El Niño events continues all the way to the coast, warming SST (by zonal advection) in a wider meridional band than the equatorially trapped thermocline anomalies, and pumping equatorial water poleward along the coast.The South Equatorial Current originates as a combination of equatorial upwelling, mixing and advection from the NECC, and Peru coastal upwelling, but its sources and their variability remain unresolved. Similarly, while much of the Equatorial Undercurrent flows southeast into the Peru Undercurrent and supplies the coastal upwelling, a quantitative assessment is lacking. We are still unable to put together the eastern interconnections among the long zonal currents of the central Pacific. 相似文献
6.
INTRODUCTIONSincetheTOGA-COARElOP(October1992--March1993),usingthelOPdatamanyscientistshaveanalyzedthedifferenttimescaleair-seainteractionduringoccurringanddevelopingperiodof1992/1993EINifio,andespeciallyemphasizedtheintraseasonalvariation(Wuetal.,1993;Liu,1993;WuandSheng,1993).ThishasgottenanewunderstandingoftheEINino*ThisworkissupportedbytheNationalKeyProjectStudiesonShort-rangeClimatePredictionSysteminChinaundercontractNo.96--908-04-02--2.1.FirstinstituteofOceanography,S… 相似文献
7.
热带西太平洋暖池异常东伸与热带东太平洋增温 总被引：7，自引：1，他引：6
本文利用“Climate Diagnostics Bulletin”、“Oceanographic Monthly Summary”、美国夏威夷水位中心提供的资料以及TOGA-COAREIOP资料,分析了1992～1993厄尔尼诺事件中西太平洋暖池、东太平洋SST对异常风场的响应,结果指出:由于西风暴发而引起的西太平洋暖水向东输送,不仅导致西太平详水位降低,而且导致温跃层显着升高,进而引起上层海水热含量显着减少,这种减少在温跃层更为明显.东太平洋与此相反,热含量与温跃层深度出现正距平,正距平中心出现时间比西太平洋的负距平均晚两个月;暖池28℃等温线的异常东伸是海流对低空西风异常直接响应的结果,定量估算表明,纬向流异常所引起的温度平流是暖池28℃等温线异常东伸的主要动力,是热带东太平洋异常增温的主要原因之一. 相似文献
8.
Kentaro Ando Yoshifumi Kuroda Yosuke Fujii Tatsuya Fukuda Takuya Hasegawa Takanori Horii Yasuhisa Ishihara Yuji Kashino Yukio Masumoto Keisuke Mizuno Motoki Nagura Iwao Ueki 《Journal of Oceanography》2017,73(4):403-426
The Triangle Trans‐Ocean Buoy Network (TRITON) project by the Japan Agency for Marine-Earth Science and Technology began with deployment in the western tropical Pacific Ocean in 1998 and has shifted to steady, long-term observations since 1999. After on-site inter-comparison with the Autonomous Temperature Line Acquisition System mooring system of the Tropical Atmosphere and Ocean (TAO) array by the National Oceanic and Atmospheric Administration, the TRITON array became the international TAO/TRITON array in 2000 as a key component of the Global Ocean and Climate Observing Systems. The TAO/TRITON array took over from the TAO array, which was developed during the Tropical Ocean and Global Atmosphere program (1985–1994), and replaced the western part of TAO with new additional real-time measurements of salinity and ocean currents. In 2001, two TRITON moorings were deployed in the eastern Indian Ocean for capturing the eastern pole of the Indian Ocean Dipole. From this initiative, the Indian Ocean Observing System (IndOOS) was designed, and the Indian Ocean mooring array (Research Moored Array for Africa–Asian–Australian Monsoon Analysis and Prediction) was developed as a key component of IndOOS. In this paper, 15 years of progress in the TRITON project in the western Pacific and eastern Indian Oceans is reviewed with regards to scientific outcomes, technological development, and collaborations with international and domestic partners. Future directions for sustainable observation in the Pacific and Indian Oceans are also discussed. 相似文献
9.
《Deep Sea Research Part II: Topical Studies in Oceanography》1999,46(1-2):279-303
The mean horizontal flow field of the tropical Atlantic Ocean is described between 20°N and 20°S from observations and literature results for three layers of the upper ocean, Tropical Surface Water, Central Water, and Antarctic Intermediate Water. Compared to the subtropical gyres the tropical circulation shows several zonal current and countercurrent bands of smaller meridional and vertical extent. The wind-driven Ekman layer in the upper tens of meters of the ocean masks at some places the flow structure of the Tropical Surface Water layer as is the case for the Angola Gyre in the eastern tropical South Atlantic. Although there are regions with a strong seasonal cycle of the Tropical Surface Water circulation, such as the North Equatorial Countercurrent, large regions of the tropics do not show a significant seasonal cycle. In the Central Water layer below, the eastward North and South Equatorial undercurrents appear imbedded in the westward-flowing South Equatorial Current. The Antarcic Intermediate Water layer contains several zonal current bands south of 3°N, but only weak flow exists north of 3°N. The sparse available data suggest that the Equatorial Intermediate Current as well as the Southern and Northern Intermediate Countercurrents extend zonally across the entire equatorial basin. Due to the convergence of northern and southern water masses, the western tropical Atlantic north of the equator is an important site for the mixture of water masses, but more work is needed to better understand the role of the various zonal under- and countercurrents in cross-equatorial water mass transfer. 相似文献
10.
Using a gridded array for real-time geostrophic oceanography(Argo) program float dataset, the features of upperocean salinity stratification in the tropical Pacific Ocean are studied. The salinity component of the squared Brunt-V?is?l? frequency N~2( N_S~2) is used to represent salinity stratification. Layer-max N_S~2(LMN), defined as the N_S~2 maximum over the upper 300 m depth, and halocline depth(HD), defined as the depth where the N_S~2 maximum is located, are used to specifically describe the intensity of salinity stratification. Salinity stratification in the Topical Pacific Ocean has both spatial and temporal variability. Over the western and eastern equatorial Pacific, the LMN has a large magnitude with a shallow HD, and both have completely opposite distributions outside of the equatorial region. An obvious seasonal cycle in the LMN occurs in the north side of eastern equatorial Pacific and freshwater flux forcing dominates the seasonal variations, followed by subsurface forcing.At the eastern edge of the western Pacific warm pool around the dateline, significant interannual variation of salinity stratification occurs and is closely related to the El Ni?o Southern Oscillation event. When an El Ni?o event occurs, the precipitation anomaly freshens sea surface and the thermocline shoaling induced by the westerly wind anomaly lifts salty water upward, together contribute to the positive salinity stratification anomaly over the eastern edge of the warm pool. The interannual variations in ocean stratification can slightly affect the propagation of first baroclinic gravity waves. 相似文献
11.
12.
ENSO循环相关的海洋异常信号传播特征及其机制 总被引：3，自引：0，他引：3
通过分析最新的海洋模式同化资料(EstimatingtheCirculationandClimateoftheOcean,EC CO),研究了ENSO循环相关的海洋异常信号在太平洋中的传播过程。研究发现,导致ENSO位相变化的温跃层异常信号主要从北太平洋西传而来,该区与赤道东太平洋相反的温跃层异常信号到达西太暖池区,再从西太暖池沿赤道传到东太平洋,可使ENSO向反位相发展。该异常信号沿赤道东传过程中热带西南太平洋也会出现类似的温跃层异常变化,但是随着异常信号东移和从南太平洋东边界10°S左右传来的反异常信号入侵,热带西南太平洋的异常信号逐渐减弱并消失。稳定性分析表明,北太平洋较大面积区域存在斜压不稳定性或正压不稳定性,有利于ENSO相关的温跃层异常信号以Rossby波形式有效地西传;而在南太平洋,不稳定区的面积较小,且主要局限于海盆东侧,因而传播较弱,这样就造成了ENSO信号在太平洋南、北半球的非对称传播。一般来说,ENSO信号主要在以赤道波导区、东边界、北太平洋纬向区域和西边界组成的回路中循环,在南半球的传播不明显。 相似文献
13.
对海洋中起伏运动(heaving)信号的时空分布研究能够帮助我们更好地了解气候系统中的年际和年代际变率。文章通过再分析资料和模式对太平洋区域的heaving主要模态进行了研究。研究结果表明: 太平洋区域主要存在两种heaving模态: 第一模态主要表现为赤道东西两侧的温跃层异常信号反位相; 第二模态表现为赤道区域和副热带区域的温跃层异常信号呈现反位相变化的规律。本文对这两个主要heaving模态所涉及的物理过程进行详细讨论, 结果表明: 东西反位相模态主要是受赤道波动调节的结果; 而经向结构模态则主要是由赤道地区的波动和副热带区域的风应力旋度异常作用共同导致。此外, 我们还讨论了heaving模态可以通过海洋波动以及Ekman输送等过程对海盆尺度的热输送(振幅约为5×1014W)以及海洋热含量(振幅约为1.5×1020J)的再分配起到了关键的调制作用, 进一步表明heaving模态对全球气候变化有着重要的作用。 相似文献
14.
本文使用SODA(simple ocean data assimilation)海洋同化资料,系统分析了厄尔尼诺-南方涛动(El Ni?o-Southern Oscillation,ENSO)循环中冷暖位相期间热带太平洋上层海洋环流的演变规律,探讨了形成海洋环流异常的新机制。结果表明,在厄尔尼诺成熟期,热带中东太平洋赤道潜流最弱,赤道两侧出现反气旋性环流异常;西太平洋赤道外热带海域出现气旋性环流异常,该区南、北赤道流、棉兰老流、黑潮、新几内亚沿岸潜流及南赤道逆流增强;北赤道逆流区出现异常气旋性环流串,北赤道逆流接近正常。在厄尔尼诺衰退期和拉尼娜发展期,热带中西太平洋赤道潜流达到极强,赤道两侧出现气旋性环流异常;西太平洋赤道外热带海域异常环流减弱,该处主要流场的强度减弱或处于正常状态;北赤道逆流区反转为异常西向流。结果表明, ENSO循环期间的上层海洋环流异常受到热带太平洋温跃层深度异常产生的压强梯度力异常调控,在赤道外热带海洋温跃层深度异常和科里奥利力共同作用产生大尺度海洋环流异常,而在赤道海域,海洋温跃层深度异常和Gill效应造成赤道潜流异常以及关于赤道对称的气旋或反气旋性环流异常。 相似文献
15.
ENSO循环过程中次表层海洋信号的传播和变化 总被引：2，自引：0，他引：2
利用SODA等资料分析了热带太平洋次表层海洋要素的变化特征,结果表明,ENSO循环过程中次表层异常海温信号在赤道外向西传播的路径与温跃层深度的分布有一定关系,10oN附近是气候平均温跃层深度的极小值区域,温跃层在该区域形成了一个从东到西的阻隔带,阻挡了来自赤道地区的ENSO信号继续向北传播,从而转向西传播;而南半球温跃层深度的气候分布不具备这一特征,不利于ENSO信号在南半球的向西传播。进一步的研究还表明,ENSO信号在整个循环过程中,异常海温的主周期是变化的,特别是在沿10oN附近向西传播的过程中,ENSO信号的主周期变化较大。推断西太平洋暖池区域的ENSO信号除了在循环过程中自东太平洋10oN传来的以外,还受其他因素的影响,例如局地的大气变化引起的海温异常,以及来自中高纬度的异常海温信号等因素。 相似文献
16.
An extended variable-grid global ocean circulation model and its preliminary results of the equatorial Pacific circulation 总被引：2，自引：0，他引：2
1IntroductionThetropicalPacificOceanplaysanimpor-tantroleintheclimatevariabilitiessuchasElNi-no-SouthernOscillation(ENSO)phenomenon(Chao,1993).ManystudieshavefoundthatthetropicalPacificvariabilitiescanhavesignifi-cantinfluenceontheoceancirculationintheseasadjacenttoChina(Yu,1985;Chaoetal.,1996;Wangetal.,2002).TheseaareaadjacenttoChinaischaracterizedbyitscomplextopog-raphyandnumerousnarrowstraits,andthusre-quiresafinegridtoresolve.Tostudytheinter-actionbetweenthetropicalPacificandChinas… 相似文献
17.
利用NCEP、SODA等再分析资料,对东太平洋上层海洋的热量收支进行了计算,研究了产生ENSO冷暖事件强度非对称的可能原因。对海表温度异常(SSTA)的分析发现,在东太平洋SSTA存在明显的正偏,即El Nio事件中正异常的幅度大于La Nia事件中负异常的幅度,体现出ENSO事件的非对称性。通过对上层海洋热量收支的计算发现,造成ENSO事件非对称性的可能原因有3个:(1) 非线性温度平流,水平非线性温度平流在ENSO冷暖事件中均为正值,因此增强El Nio事件而减弱La Nia事件;(2) 次表层温度异常对温跃层深度异常的非线性响应,由于东太平洋温度剖面的特性,使得次表层温度异常对El Nio期间正的温跃层深度变化更为敏感,造成次表层温度异常幅度在El Nio期间比La Nia期间大,从而通过－wT′z项引起上层海温的非对称性;(3) 赤道太平洋的纬向风异常的正偏:由于赤道太平洋存在较强的纬向西风,导致东太平洋温跃层深度异常正偏,进而造成次表层温度异常的非对称－wT′z,并通过项影响上层海温的非对称性。 相似文献
18.
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
19.
Hydrography of the eastern tropical Pacific: A review 总被引：3，自引：10，他引：3