Three-Dimensional Velocity Field and Cross-Frontal Water Exchange in the Kuroshio Extension     

Susana Sainz-Trápaga  Takashige Sugimoto 《Journal of Oceanography》2000,56(1):79-92

A spread of warm water from the first crest of the Kuroshio Extension is periodically enhanced by northward warm water intrusions from the main current. The water type in the spread area was previously found to be the same as that in the Kuroshio front at depth. In looking for the possible mechanism responsible for the northward warm water intrusions, a dynamic analysis in the Kuroshio front was carried out by using CTD, ADCP, AVHRR and ARGOS buoy data, obtained in 1996 by the R.V. Hakuho Maru. Downstream, cross-stream and vertical velocities in the Kuroshio Extension were found by using a "stream coordinate system". The velocity field in the Kuroshio front at the first crest showed a double structure with two surface velocity maxima. In the inner part of the front, relatively high cross-stream (northward) and vertical (upward) velocities were found. Thus, this study suggests that while water particles flow downstream along the first stationary meander of the Kuroshio Extension, they also experience lateral and vertical movements which allow the deeper water from an upstream location to rise to the surface layer, and in certain locations to deflect northward. By assuming isopycnal movement and conservation of potential vorticity, it was found that in those locations where anticyclonic curvature of the meander increases, warm water is more likely to deflect northward. High ageostrophic components observed in the first 300 m of the water column are probably related to the relatively high cross-stream and vertical velocities in the inner part of the front.  相似文献   

东海北部黑潮区浮游动物的多样性研究   总被引：5，自引：1，他引：5  

洪旭光  张锡烈  俞建銮  孟凡 《海洋学报》2001,23(1):139-142

由于浮游动物在海洋生态系统中处于主导地位及其对生物地球化学循环和全球变化的重要影响,浮游动物与环境间相互作用的研究已成为现代海洋生态学研究的一个核心问题[1].  相似文献   

Kuroshio extension variability explored through assimilation of TOPEX/POSEIDON altimeter data into a quasi-geostrophic model     

Yousuke Nishihama  Motoyoshi Ikeda 《Journal of Oceanography》2007,63(6):879-895

Mesoscale features in the eastward extension of the Kuroshio were investigated using assimilation of TOPEX/POSEIDON (T/P) data into a three-layer quasi-geostrophic model. The T/P data exhibited an elongated state of the southern recirculation gyre in 1993–95 and 1997, between whose two periods the gyre had a contracted state in 1995–96. A few stationary eddies were located in the southern gyre during the contracted state. The baroclinic instability, which was indicated by the phase shift from the uppermost-to the lowest-layer anomalies toward the downstream side, was evident near the Kuroshio Extension (KE) path. Since the instability never appeared in the artificial model without bottom topography, the topographic barrier for the eastward flow in the lowest layer was a necessary condition for the instability. The instability synchronized with the transition in the western region of the KE axis from the elongated to the contracted states. This evolution was interpreted as if the baroclinic instability played some part in the KE states and was a trigger for the transition from the elongated to the contracted states.  相似文献   

非线性共轭梯度法在东海黑潮流计算中的应用   总被引：4，自引：0，他引：4  

陈红霞  袁业立  刘娜  曲媛媛 《海洋学报》2003,25(6):31-38

基于现有的几种海流计算方法,根据与P矢量法相同的动力特性和内在假设,对海流计算提出了一种简单、高效、易扩展、适用范围广的新方法:非线性共轭梯度法.利用1989年4月以来的"中日黑潮合作调查研究"6个航次的CTD资料,对东海黑潮流区域应用非线性共轭梯度法进行了海流计算.通过与船载ADCP实测结果比较表明,非线性共轭梯度法是可行的.  相似文献   

Numerical study of the influence of Kuroshio Current on the thermocline in the sea area around Taiwan Island     

张文静  沙文钰 《海洋预报》2001,18(Z1):17-24

1 INTsoDUcrIONTemperature is one of the most impoFtant essential factors of ocean, and its verticalstructure, especially the phenomenon ofthermocline, is concerned by military and manufacturepractices at all times. There are two classes of research methods for thermocIine, statisticmethod and numerical method. In recent years, more attention has been paid to the latterwhich becomes the primary development direction. Since Munk et al (1948) pot forward1-D model of thermocline at steady sta…  相似文献   

冲绳海槽中西部边缘区沉积物成因和沉积环境     

高素兰  王慧艳  辛春英 《海洋科学进展》1998,(3)

本文根据１９９６年“中－法合作东海计划”在冲绳海槽中西部边缘区所取柱状样岩芯沉积物粒度分析资料,对该区沉积物特征进行研究。结果表明,火山沉积和富含生物的半远洋深海软泥沉积是本区的主要特征。以４８１ｃｍ为界,上、下两层沉积物截然不同,可能是沉积物的来源不同或者是水动力条件的差异。该区主要受火山活动的影响,其次是黑潮、大洋风暴  相似文献   

利用卫星遥感资料对南海北部陆架海洋表层温度锋的分析   总被引：4，自引：0，他引：4  

王磊  王丽娅  魏皓 《中国海洋大学学报(自然科学版)》2004,34(3):351-357

利用7年(1993～1999)月平均的SST卫星遥感资料，分析了南海北部陆架区域海洋表层温度锋在一年中的逐月变化特征，表明南海北部陆架海洋表层温度锋存在明显的季节内变化。结合风场的卫星遥感资料，分析了东北季风对南海北部陆架温度锋的影响，表明东北季风风速的增加有利于温度锋强度的增强。通过对黑潮南海流套入侵较强的1999年2月与流套入侵较弱的1998年2月的SST卫星遥感资料的对比分析，考察了黑潮南海流套的入侵对南海北部陆架温度锋的影响，结果表明黑潮流套的较强入侵能够增加陆架温度锋的强度，对温度锋的走向也会产生一定的影响。  相似文献   

黑潮和中国近海环流   总被引：9，自引：0，他引：9  

伍伯瑜 《台湾海峡》1991,10(1):25-32

本文根据历史资料总结和讨论了黑潮对中国近海环流影响的基本结果,指出经巴士海峡进入南海和沿台湾海峡向北运动的黑潮分支,其年际变化明显,并认为该黑潮分支的运动状况对中国近海特别是南海和东海南部的中、下层环流影响显著,需要作进一步的调查研究。  相似文献   

东海黑潮热输送及其与黄淮平原区汛期降水的关系   总被引：22，自引：0，他引：22  

翁学传  张启龙  杨玉玲  颜廷壮 《海洋与湖沼》1996,27(3):237-245

根据日本气象厅1956—1990年PN（G）断面观测资料分析东海黑潮热输送的变异特征，并探讨其冬季热输送与黄淮平原区汛期（6－8月）降水的关系。结果表明，黑潮通过PN（G）断面多年平均的热输送达15．74×1014W，其中冬季热输送的年际和长期变化特别明显；冬季热输送年际变化的周期主要为对．23.4a、3.5a、和2.6a，长期变化总趋势是70年代末以前各年热输送距平均为负值，对年代末接近多年平均值，进入80年代各年距平值不仅为正且逐年增大；东海黑潮冬季热输送与黄淮平原区汛期降水具有相近的长期变化趋势，两者间存在较好的负相关关系。  相似文献   

Eddy Shedding from the Kuroshio Bend at Luzon Strait   总被引：16，自引：1，他引：16  

Yinglai?JiaEmail author  Qinyu?Liu 《Journal of Oceanography》2004,60(6):1063-1069

TOPEX/POSEDIENT-ERS satellite altimeter data along with the mean state from the Parallel Ocean Climate Model result have been used to investigate the variation of Kuroshio intrusion and eddy shedding at Luzon Strait during 1992–2001. The Kuroshio penetrates into the South China Sea and forms a bend. The Kuroshio bend varies with time, periodically shedding anticyclonic eddies. Criteria of eddy shedding are identified: 1) When the shedding event occurs, there are usually two centers of high Sea Surface Height (SSH) together with negative geostrophic vorticity in the Kuroshio Bend (KB) area. 2) Between the two centers of high SSH there usually exists positive geostrophic vorticity. These criteria have been used to determine the eddy shedding times and locations. The most frequent eddy shedding intervals are 70, 80 and 90 days. In both the winter and summer monsoon period, the most frequent locations are 119.5°E and 120°E, which means that the seasonal variation of eddy shedding location is unclear.  相似文献