0220号热带风暴(米克拉)特征分析     

李孟植 《海洋预报》2003,20(3):7-11

南海是热带气旋活动较为频繁的地区之一。该地区因其独特的地理环境和复杂的热带大气环流系统，在热带气旋预报工作上存在一定的困难。本文在分析一些气象图表资料的基础上，对2002年第20号热带风暴(米克拉)的形成、发展及消亡进行了探讨和研究。主要从形成的背景环流，气旋的结构等方面入手，总结出一些该气旋所具备韵特有流场，从而为以后的南海自生热带气旋预报工作积累一定经验。  相似文献   

1998年夏季季风爆发前后南海上层环流的诊断分析   总被引：4，自引：0，他引：4  

王桂华  许建平 《热带海洋学报》2001,20(1):36-43

基于1998年南海季风试验（SCSMEX，South China Sea Monsoon Experiment)期间2个强化观测航次（4－5月及6－7）所获温盐深（CTD）资料，利用一个改进逆模式研究了夏季季风爆发前后南海环流的演变特征。诊断计算表明，在此期间南海环流主要表现为两脊两槽型，即越南以东和菲律宾以西呈反气旋式环流，南海北部和南海中部呈气旋式环流。但对局部区域而言，可以发现在季风爆发前后其环流结构有明显的差异。上述计算结果亦与等压面上海水密度分布的定性分析结果及同期观测的ADCP资料进行了比较，结果表明模式计算所得到的南海上层环流主要特征与定性分析结果及实测资料大体一致，诊断结果可作为南海上层季风环流演变机制研究的依据。  相似文献   

冲绳海槽热流机制浅析   总被引：2，自引：0，他引：2  

李官保  李乃胜 《海洋科学》2002,26(9):57-61

冲绳海槽是一个高热流区，平均热流值极高，但不均匀，实测最小值与最大值相差三个数量级以上，结合海槽地区的构造和地球物理特征，探讨了导致这一高而分散热流特征的多种因素。包括异常壳幔结构。海底热液循环以及地下水对流等，并分析了相应的控制机制。  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   

渤海海峡断面温度结构及流量的季节变化   总被引：3，自引：2，他引：3  

林霄沛  吴德星  鲍献文  江文胜 《中国海洋大学学报(自然科学版)》2002,32(3):355-360

作者采用 POM模式 ,利用从卫星遥感资料反演的风和海表温度 (SST)数据并考虑 M2分潮作用 ,对渤海海域的温度、流场的三维结构进行数值计算。根据数值模式的计算结果 ,重点分析渤海海峡温度结构和水交换的季节变化特征。结果表明风应力和 SST的季节性变化导致渤海海峡的水交换流型、温度结构和流量有明显的季节性变化。  相似文献   

P矢量方法在南海夏季环流诊断计算中的应用   总被引：8，自引：4，他引：8  

卜献卫  袁耀初  刘勇刚 《海洋学报》2001,23(3):8-17

基于1998年6～7月南海调查航次的CTD资料,对南海环流采用最近发展的P矢量方法进行诊断计算.计算结果:黑潮向西入侵南海,然后做反气旋弯曲向东北方向流动,最终有通过巴士海峡流出南海的趋势.在南海北部存在一个气旋性环流,这个环流的强度和范围随深度增加而减小.该环流的冷中心位置随深度增加稍向南移.南海中部、越南以东海域存在一个明显的气旋涡和反气旋涡,尤其在200m及其以上水层均相当稳定,反气旋涡位于越南以东,其中心位置在11°53'N,111°50'E,气旋涡的中心位置在13°17'N,112°55'E,两者的尺度皆约为250km.吕宋岛西侧存在一个反气旋涡.在计算海区南部、巴拉望岛西南海域,100m以上层存在一个反气旋式涡.从各层流场分布均可以显示海流在西部强化的现象.  相似文献   

好望角附近海域春季大风的几种主要形势分析   总被引：1，自引：1，他引：1  

马卫民  陈信雄 《海洋预报》2001,18(2):62-66

通过普查和分析，概括出了春季好望角附近海域三种主要大风出现时的模型图，并以一个月中逐日4次船舶测风报告为例，分析了好望角大风的某些主要特征。  相似文献   

The circulation of the eastern tropical Pacific: A review   总被引：5，自引：9，他引：5  

William S. Kessler   《Progress in Oceanography》2006,69(2-4):181

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   

Fine resolution 3D temperature fields off Kerguelen from instrumented penguins     

Jean-Benoît Charrassin  Young-Hyang Park  Yvon Le Maho  Charles-Andr Bost 《Deep Sea Research Part I: Oceanographic Research Papers》2004,51(12):2091-2103

The use of diving animals as autonomous vectors of oceanographic instruments is rapidly increasing, because this approach yields cost-efficient new information and can be used in previously poorly sampled areas. However, methods for analyzing the collected data are still under development. In particular, difficulties may arise from the heterogeneous data distribution linked to animals’ behavior. Here we show how raw temperature data collected by penguin-borne loggers were transformed to a regular gridded dataset that provided new information on the local circulation off Kerguelen. A total of 16 king penguins (Aptenodytes patagonicus) were equipped with satellite-positioning transmitters and with temperature–time–depth recorders (TTDRs) to record dive depth and sea temperature. The penguins’ foraging trips recorded during five summers ranged from 140 to 600 km from the colony and 11,000 dives >100 m were recorded. Temperature measurements recorded during diving were used to produce detailed 3D temperature fields of the area (0–200 m). The data treatment included dive location, determination of the vertical profile for each dive, averaging and gridding of those profiles onto 0.1°×0.1° cells, and optimal interpolation in both the horizontal and vertical using an objective analysis. Horizontal fields of temperature at the surface and 100 m are presented, as well as a vertical section along the main foraging direction of the penguins. Compared to conventional temperature databases (Levitus World Ocean Atlas and historical stations available in the area), the 3D temperature fields collected from penguins are extremely finely resolved, by one order finer. Although TTDRs were less accurate than conventional instruments, such a high spatial resolution of penguin-derived data provided unprecedented detailed information on the upper level circulation pattern east of Kerguelen, as well as the iron-enrichment mechanism leading to a high primary production over the Kerguelen Plateau.  相似文献   

An unsteady wave driver for narrowbanded waves: modeling nearshore circulation driven by wave groups     

Andrew B. Kennedy  James T. Kirby   《Coastal Engineering》2003,48(4):257-275

In this paper, we derive an unsteady refraction–diffraction model for narrowbanded water waves for use in computing coupled wave–current motion in the nearshore. The end result is a variable coefficient, nonlinear Schrödinger-type wave driver (describing the envelope of narrow-banded incident waves) coupled to forced nonlinear shallow water equations (describing steady or unsteady mean flows driven by the short-wave field). Comparisons with experimental data show that good accuracy can be obtained for cases of nonbreaking wave transformation. Numerical simulations show that the interaction of wave groups with longshore topographic nonuniformities generates strong edge wave resonances, providing a generating mechanism for low-order edge waves.  相似文献