南海上层环流观测研究进展   总被引：25，自引：1，他引：25  

李立 《台湾海峡》2002,21(1):114-125

回顾了近50a来南海环流研究的进展，重点介绍了近期有关南海上层总环流的观测研究成果，并就南海季风急流、南海暖流、南海南部的次海盆尺度环流，以及南海东北部环流的几个问题进行了专门讨论。  相似文献   

The CANALES experiment (1996-1998). Interannual, seasonal, and mesoscale variability of the circulation in the Balearic Channels     

J. -M. Pinot  J. L. Lpez-Jurado  M. Riera 《Progress in Oceanography》2002,55(3-4)

Repeated hydrographic casts, mooring time series and satellite sea surface temperature collected during the CANALES experiment (1996–98) are used to describe the thermohaline circulation in the Balearic Channels (western Mediterranean) and to analyze its variability. Mass transports are estimated by inverse calculations. The role played by each channel in the meridional water exchange is clarified: the Ibiza Channel funnels southward cool, saline, northern waters whereas the Mallorca Channel appears as the preferred route for the northward progression of warm, fresh, southern waters. A neat interannual trend is revealed by the continuous decrease of the amount of Western Mediterranean Intermediate Waters (WIW) brought by the Northern Current, reflecting the increase in temperature of the winter mixed layer in the northern Mediterranean that occurred each year between 1996 and 1998. A clear seasonal signal was also seen in the transport of the Northern Current which decreased from 1 to 1.4 Sv in winter to < 0.5 Sv in summer. The current intensified again in fall. A number of mesoscale eddies, from 20 to 70 km in size, most of them anticyclonic vortex eddies were brought by the unstable Northern Current, these eddies strongly perturbed the water exchange in the Ibiza Channel forcing retroflections of northern waters back to the north-east into the Balearic Current. These eddies either stayed stalled for several months in the Gulf of Valencia to the north of the channel, or were slowly funnelled southward through the channel narrows. A decreasing trend was observed in the mesoscale activity of the Northern Current between 1996 and 1998. Conversely, large, anticyclonic eddies, 150-km diameter, progressively invaded the Algerian Basin to the south of the channels in 1997–98 and forcing northward inflows (up to 0.75 Sv) of fresh and warm waters of Atlantic origin (AW) into the Mallorca Channel. The marked interannual differences observed in both northern and southern eddy activity may be linked to the interannual variability of the large scale thermohaline circulation.  相似文献   

热带印度洋偶极子发生和演变机制的数值研究   总被引：5，自引：0，他引：5  

李东辉  张铭  张瑰  谭言科 《海洋科学进展》2005,23(2):135-143

对中国科学院大气物理研究所(IAP)大气科学和地球流体力学数值模拟国家重点实验室(LASG)发展的第三代海洋模式(L30T63 OGCM)进行了改进。分析了该模式1959年1月—1998年12月的40a积分结果，以此研究热带印度洋偶极子发生、发展和消亡的物理机制。对数值模拟结果的分析表明，赤道印度洋表面异常东风引起的异常环流结构是偶极子发生、发展的主要动力学原因，其表面异常东风转换为异常西风所引起的异常环流结构调整是偶极子消亡的主要动力学原因；海气界面热通量异常的交换对热带印度洋海表温度距平偶极子模态的形成和演变起着重要的作用；垂直输送作用是热带印度洋次表层海温偶极子模态发生和演变的主要物理机制。  相似文献   

Recovery of thermohaline circulation under CO₂ stabilization and overshoot scenarios   总被引：1，自引：0，他引：1  

Norikazu. Nakashiki  Dong-Hoon Kim  Frank O. Bryan  Yoshikatsu Yoshida  Daisuke Tsumune  Koki Maruyama  Hideyuki Kitabata 《Ocean Modelling》2006,15(3-4):200

In this study we examine the behavior of the thermohaline circulation, as simulated by the Community Climate System Model version 3 (CCSM3), for several centuries following CO₂ stabilization for the SRES B1 and A1B scenarios and for an “overshoot” scenario in which CO₂ levels temporarily reach the same level as in the A1B scenario before declining to an ultimate stabilization level that is identical to the B1 case. While we find no evidence for irreversible changes of the thermohaline circulation in the overshoot experiment, the interplay of the different timescales of the temperature response of the surface and interior ocean does lead to a number of differences in the long-term response of the ocean between it and the B1 stabilization scenario where the same GHG levels are approached by different paths. The stronger initial warming and its slow penetration into the deeper ocean, followed by a transient surface cooling in the overshoot scenario leads to lower static stability, deeper mixing, and a more rapid recovery of the thermohaline circulation than in the B1 stabilization scenario. While the overshoot scenario recovers surface conditions (e.g. SST, sea ice extent) very similar to the B1 scenario shortly after reaching the same GHG levels, the additional accumulation of heat in the interior ocean during the period of higher forcing causes the global mean ocean temperature and steric sea level to remain higher than in the B1 stabilization scenario for at least another several centuries.  相似文献   

一种基于BP算法学习的小波神经网络   总被引：2，自引：1，他引：2  

陈哲  冯天瑾  陈刚 《中国海洋大学学报(自然科学版)》2001,31(1)

为发展 Szu的基于信号表示的小波神经网络 ,提出一种多输入多输出的小波网络模型 ,网络隐层采用框架小波函数、输出层采用 Sigmoid激励函数 ,并选用“熵误差函数”以加速网络的学习速度。奇偶判别和混沌时间序列预测例子的实验结果表明了它具有良好的函数逼近能力和推广能力 ,收敛速度和均方误差均优于相同结构的多层感知器模型。  相似文献   

黄海、渤海底层温度数值预报方法的研究     

王宗山  徐伯昌  龚滨  邹娥梅  李繁华 《海洋科学进展》1996,(3)

根据文献［ｌ］建立的底层温度（ＴＨ）与其水柱垂向平均温度（）的经验关系，结合流体动力学方程和（垂向平均）热传导方程，发展了以水气温差和风速为已知量的底层温度二维数值预报模式。该模式避开了海面热量和动量输入在垂直水柱中分配的复杂物理过程而直接报出底层水温场，具有较好的实用性；此外，从试报结果看，效果令人满意。  相似文献   

Wind-induced eddy motion in the lower St. Lawrence Estuary     

G. Mertz  V.G. Koutitonsky  Y. Gratton  M.I. El-Sabh 《Estuarine, Coastal and Shelf Science》1992,34(6)

  相似文献   

连云港近岸海域物理自净能力研究及水质预测——Ⅲ.西大堤建成后对物质输运的影响     

赵可胜  娄安刚  王学昌 《中国海洋大学学报(自然科学版)》1994,(Z1)

在连云港近岸海域计算潮流场基础上建立拉格朗日余流模型,并对连云港市两大堤建成前后的拉格朗日余流变化进行了分析,且选择有代表性的排污口进行了数值跟踪。  相似文献   

松辽盆地西部张裂缝预测的应力场方法     

朱庆杰  朱而勤  尹万泉  吴战国 《中国海洋大学学报(自然科学版)》1995,(3)

以松辽盆地地质资料为基础，介绍了应力场和张裂缝预测的计算方法。通过了各种岩性的张破裂概率隶属函数，预测松辽盆地酉部张裂缝区的分布。据此，为今后的油气勘探提出了几点认识和建议。  相似文献   

一个具有下垫面温度耦合的大气环流的统计—动力模式     

陈英仪 《海洋预报》1992,(4)

本文从动力学定律出发,推导了一个线性的、具有下垫面温度耦合的大气环流的统计—动力模式,并用该模式对500hPa高度场及1000hPa温度场作1～30天的平均预报试验。模式的预报结果大大优于惯性预报,但耦合与不耦合的结果差别不大。  相似文献