Reconstruction of vertical thermal structure from several subsurface temperatures in the China Seas and adjacent waters

Empirical Orthogonal Function (EOF) analysis is used in this study to generate main eigenvector fields of historical temperature for the China Seas (here referring to Chinese marine territories) and adjacent waters from 1930 to 2002 (510 143 profiles). A good temperature profile is reconstructed based on several subsurface in situ temperature observations and the thermocline was estimated using the model. The results show that: 1) For the study area, the former four principal components can explain 95% of the overall variance, and the vertical distribution of temperature is most stable using the in situ temperature observations near the surface. 2) The model verifications based on the observed CTD data from the East China Sea (ECS), South China Sea (SCS) and the areas around Taiwan Island show that the reconstructed profiles have high correlation with the observed ones with the confidence level >95%, especially to describe the characteristics of the thermocline well. The average errors between the reconstructed and observed profiles in these three areas are 0.69°C, 0.52°C and 1.18°C respectively. It also shows the model RMS error is less than or close to the climatological error. The statistical model can be used to well estimate the temperature profile vertical structure. 3) Comparing the thermocline characteristics between the reconstructed and observed profiles, the results in the ECS show that the average absolute errors are 1.5m, 1.4 m and 0.17°C/m, and the average relative errors are 24.7%, 8.9% and 22.6% for the upper, lower thermocline boundaries and the gradient, respectively. Although the relative errors are obvious, the absolute error is small. In the SCS, the average absolute errors are 4.1 m, 27.7 m and 0.007°C/m, and the average relative errors are 16.1%, 16.8% and 9.5% for the upper, lower thermocline boundaries and the gradient, respectively. The average relative errors are all <20%. Although the average absolute error of the lower thermocline boundary is considerable, but contrast to the spatial scale of average depth of the lower thermocline boundary (165 m), the average relative error is small (16.8%). Therefore the model can be used to well estimate the thermocline. Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No.KZCX-3W-222; KZCX2-YW-Q11-02) and National Basic Research Program of China (No.2007CB411802; 2006CB403601)     

ENSO相联系的热带太平洋上层海洋异常环流

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。     

西北太平洋中尺度涡半径与涡动能的统计关系

中尺度涡的半径与涡动能之间的关系及其内在机制的研究,对我们理解中尺度涡旋的三维结构特征及其变异规律有很大的帮助。本文利用AVISO卫星高度计融合数据,基于流场几何特征的识别方法对西北太平洋(10°～52°N, 120°～180°E)的中尺度涡进行了识别追踪,并由此分析了该区域内中尺度涡的半径与涡动能(Eddy Kinetic Energy, EKE)的统计关系。结果表明该区域中尺度涡的半径与EKE之间存在类似翻转高斯函数的递增关系,特别是在涡旋半径达到一定程度后,EKE将不随半径的变大而继续增强。而且该关系与纬度密切相关,相同半径条件下,涡旋的EKE近似与其所在纬度的第一斜压Rossby变形半径的平方呈反比。进一步分析表明该统计关系与中尺度涡所处的发展阶段没有明显的联系。该结果为建立一个实用性的参数化、归一化的中尺度涡模型提供了一定的理论基础。     

Erratum to: Seasonal variability of zonal heat advection in the mixed layer of the tropical Pacific

<正>Erratum to:Chinese Journal of Oceanology and Limnology Vol.31 No.6,P.1356-1367,2013http://dx.doi.org/10.1007/s00343-014-3019-4The supporting grant information on the footnote of the original version of this article needs to be altered and updated.The new information is given below.     

STUDY OF ANOMALOUS SST FIELD IN TROPICAL PACIFIC IN PRECEDING YEARS OF TWO PATTERNS OF ENSO EVENTS

Analyzing the anomalous field of SST over the tropical Pacific for two kinds of ENSO events after 1956. we find that in the preceding year before the eastern pattern of El Nino event there is the La Nina event and large negative anomalies of SST in the tropical central and eastern Pacific; the preceding year before the eastern pattern of La Nina event witnesses the prevalence of the El Nino event and large positive anomalies of SST in the same waters: the preceding year before the central patterns of the El Nino (La Nina) events are generally marked by significant positive (negative) SST anomalies in central/western (eastern) tropical Pacific. The fields are just the opposite for two patterns of ENSO events. For waters in the warm pool in the western tropical Pacific, the central (eastern) pattern of El Nino event is with a warm (cool) preceding year of the pool. The warmer conditions in the western Pacific warm pool are a necessity for the occurrence of the central pattern of El Nino event.     

黄、东海热量平衡对海水温度变化贡献的估算

用多年平均水温和海面热量收支资料,计算了黄、东海热量平衡,估算了海面热量收支、海洋平流热输送、水体内部涡动热扩散等对水体温度变化的影响,讨论了冷暖水体分布和海洋平流热输送分布的概况.结果指出:秋冬季节,水温迅速下降的原因主要是海面蒸发耗热和南向的冷平流热输送;春夏季节,水温迅速上升的原因主要是进入海面的太阳总辐射的增加和北向的暖平流热输送.结果还指出,黄、东海区,冷水主要位于朝鲜西岸邻近海域和东海东部,前者冬季强,后者春季强,二者均从秋季开始出现,夏季消失;黑潮及其分支的暖平流热输送,春季最大,冬季次之,秋季最小;南向的冷平流热输送,秋季最大,冬季次之,春季最小.     

南沙暖水变化及其与ENSO和西太副高的耦合关系

南沙暖水域位于南海南部,濒临赤道,处于Walker环流上升区和南北半球气流交换的通道上,是南海海温较高的区域,也是海气相互作用的敏感地区。热带海域海洋及大气环流的变化对该海域海温的变化有着重要影响。 以往的研究表明,南海海温与赤道中、东太平洋水温和西太平洋副热带高压关系密切(钮智旺,1994;陈永利,1996)。南海是一个半封闭性海域,南海海温的变化与热带西太平洋水温之间具有非“承接”性(周发琇,1991),与西太平洋之间的水体交换不可能是引起南海海温变化的主要原因。那么,赤道中、东太平洋海温及副高是通过什么过程影响南海海温呢?它们之间的相互关系如何?西太平洋副热带高压是控制南海海域的主要天气系统，厄尔尼诺和南方涛动是热带太平洋地区海洋、大气中的两种大尺度异常现象,南海海温与它们之间的耦合关系可能就是影响海温变化的过程。本文根据综合海洋大气资料(COADS),分析了南沙暖水的变化与南海海温的关系,并借助功率谱和交叉谱分析了南沙暖水的变化周期以及与赤道东、中太平洋水温、南方涛动和西太副高之间的显著耦合频域及相互耦合振荡关系,以探讨南沙暖水与ENSO(埃尔尼诺-南方涛动)和西太副高之间的内在联系及海温变化的原因,对于研究南沙暖水域及南海海温变化的物理成因有着重要意义。     

船上海气之间湍流通量的观测研究

用６个加速度计组阵系统来监测船体姿态和运动，校正船上观测到的风湍流资料，然后用涡动相关技术计算海气之间动量，热量和水汽通量，结果表明，本观测系统可精确地消除船体运动对风湍流的影响，并获得精确的海气湍流通量。     

海温距平的ENSO模和类ENSO模的三维结构

用美国马里兰大学提供的海洋同化(SODA)月平均资料,深入揭示了ENSO模的海洋三维结构及其年际和年代际变率。研究结果指出,ENSO海洋模随深度呈明显规律变化。在热带太平洋,它由热带中东太平洋表层显著海温异常分布型随深度增加逐渐过渡为热带西太平洋次表层显著反号海温异常分布型;在赤道太平洋以赤道西太平洋暖池次表层海温显著异常与赤道中东太平洋表层海温反号显著异常为主要特征。El Nino期间,热带中东太平洋表层为强海温正距平中心,西太平洋暖池次表层为强海温负距平中心,在年际尺度上,160°E以西的西北太平洋副热带海域还存在一个与西太平洋海温异常变化反号、与热带东太平洋同号的区域;La Nina期间正好相反。ENSO循环主要由ENSO年际变率所决定,年际ENSO模具有东部型ENSO事件的海温异常分布特征,其循环是东部型冷暖事件之间的转换,在200m以浅,它具ENSO模相同的三维结构和3-5年的显著年际变化周期;年代际类ENSO模具有中部型ENSO事件的海温异常分布特征,年代际ENSO循环是中部型冷暖事件之间的转换,其影响主要限制在200m以浅的海洋上层,具有ENSO模相似的三维结构和9-23年的显著周期。     

东黄海海雾的初步分析

海雾是出现在海上的灾害性天气现象。发生在我国海面上的雾多数是平流雾,它是在海洋大气边界层中,海洋与大气相互作用的结果之一。对中国海海雾的研究,国内不少单位进行了大量的统计和分析,得到了一些有益的结果。由于缺乏海上观测资料,迄今除狩生义明在东海海区作出了初步的雾日统计以外,其它海区的分析工作大多是用沿岸台站和岛屿上的资料。为弥补这些缺陷,本文拟根