1993和1994年东海黑潮的变异

基于“长风丸”1993～1994年共8个航次的水文调查资料,采用改进逆方法计算了东海黑潮的流速、流量和热通量.计算结果表明:(1)PN断面黑潮流速在秋季时均呈双核结构;而在其他季节,有时为单核,有时为双核;黑潮主核心皆位于坡折处.黑潮以东及黑潮以下都存在南向逆流.(2)TK断面较复杂,可出现单、双或三核结构.在吐噶喇海峡中部、北部出现流核的机率较高.海峡南端及海峡深处都存在西向逆流,而且海峡南端的逆流在秋季较强.(3)在A断面,对马暖流核心位于陆坡上,但有时偏西或偏东.Vmax值的变动范围为26～46cm/s.黄海暖流位于其西侧,流速则相对减小.(4)东海黑潮流量在这两年中,在春季均出现最小值,在夏季出现最大或较大值.黑潮流量,以PN断面为例,每年四季平均流量值1994年与1993年几乎相同,但略小于1992年的平均流量值.8个航次中通过PN、TK断面的平均净流量分别为27.1×106和25.0×106m3/s.(5)8个航次中,通过PN、TK断面的热通量的平均值分别为1.99×1015和1.78×1015W.(6)在计算海域秋季和冬季均是由海洋向大气放热;夏季则均从大气吸热;春季则不确定.海面上热交换率在冬季最大,而春、夏季较小.     

1992年东海黑潮的变异

基于1992年4个航次的水文调查资料,运用改进逆方法计算了东海黑潮的流速、流量和热通量．计算结果表明：（1）PN断面黑潮在春季和秋季都有两个流核,冬季和夏季则只有一个流核．主核心皆位于坡折处．Vmax值春季最大,冬季和夏季次之,而秋季最小．黑潮以东及以下都存在逆流．（2）TK断面黑潮在冬季为两核,春、夏季为3核．海峡南端及海峡深处存在西向逆流．（3）通过A断面的对马暖流Vmax值在秋季最大,冬季最小．黄海暖流位于其西侧,相对较弱．（4）通过PN断面净北向流量夏季最大,秋季最小,而冬、春季介于上述二者之间,1992年四季平均值为28．0×106m3/s;TK断面的净东向流量也是在夏季最大;A断面净北向流量则在秋季最大．（5）PN断面4个航次的平均热通量为2．03×1015W．TK断面3个航次的平均热通量为2．00×1015W．（6）在计算海区,冬、春和秋季都是由海洋向大气放热;夏季则从大气吸热．冬季海面上热交换率最大,而夏季热交换率最小．关键词##4东海;;黑潮;;季节变化     

Variability of the Kuroshio in the East China Sea in 1992

INTRODUCTIONMostofpreviousstudiesshowthatthedynamicmethodswereoftenusedtocomputethevelocityandVToftheKuroshiointheEastChinaSea(Guan,1988;Nishizawaetal.,1982;SunandKaneko,1993).Duringrecentyearsdifferentkindsofinversemethodshavebeentriedby*ThisprojectwassupportedbytheNationalNaturalScienceFoundationofChinaundercontractNo.49776287.1.Secondinstituteofoceanography,StateOceanicAdministration,Hangzhou310012,ChinaYuanetul(1988,1991,1992a,1992b,1993,1994,1995).Theircalculatedresultsshowt…     

Analysis of the high and low temperature centers and their relation with circulations in the East China Sea

Three warm currents, the Kuroshio, its shelf intrusion branch in the northeast of Taiwan and the Taiwan Warm Current (hereafter TWC), dominate the circulation pattern in the East China Sea (hereafter ECS). Their origination, routes and variation in winter and summer are studied. Their relationship with four major high and low temperature centers is analyzed. Differing from the previous opinion, we suggest that the four major centers are generated to a great extent by the interaction of the currents in the ECS. In summer, a cold water belt in the northeast of Taiwan is preserved from winter between the Kuroshio and the TWC. The shelf intrusion branch of the Kuroshio separates the water belt, and two low temperature centers generate in the northeast of Taiwan. In the southern ECS, the TWC transports more heat flux northward to form a warm pool. But it is separated in the lower layer by the cold water driven by the intrusion branch of the Kuroshio. So the TWC and the intrusion branch of the Kuroshio play a dominating role to generate the high temperature center. The interaction among the eastward TWC, the northward Tsushima Warm Current (hereafter TSWC) and the southward Su Bei Coastal Flow (hereafter SBCF) generates the low temperature center in the northern ECS. In winter, the strengthening of the shelf intrusion branch of the Kuroshio obscures the two low temperature centers in the northeast of Taiwan. For the weakening of the TWC, the high temperature center in the southern ECS vanishes, and the low temperature center in the northern ECS shifts to south.     

The Current System in the Yellow and East China Seas

During the 1990s, our knowledge and understanding of the current system in the Yellow and East China Seas have grown significantly due primarily to new technologies for measuring surface currents and making high-resolution three-dimensional numerical model calculations. One of the most important new findings in this decade is direct evidence of the northward current west of Kyushu provided by satellite-tracked surface drifters. In the East China Sea shelf region, these recent studies indicate that in winter the Tsushima Warm Current has a single source, the Kuroshio Branch Current in the west of Kyushu, which transports a mixture of Kuroshio Water and Changjiang River Diluted Water northward. In summer the surface Tsushima Warm Current has multiple sources, i.e., the Taiwan Warm Current, the Kuroshio Branch Current to the north of Taiwan, and the Kuroshio Branch Current west of Kyushu. The summer surface circulation pattern in the East China Sea shelf region changes year-to-year corresponding to interannual variations in Changjiang River discharge. Questions concerning the Yellow Sea Warm Current, the Chinese Coastal Current in the Yellow Sea, the current field southwest of Kyushu, and the deep circulation in the Okinawa Trough remain to be addressed in the next decade. This revised version was published online in August 2006 with corrections to the Cover Date.     

东中国海环流及其季节变化的数值模拟

关于东中国海环流的研究，国内外学者已做了大量的工作。早期科学家们主要依赖于对温盐资料和少数测流资料的分析研究对渤、黄、东海的环流结构有了较系统和深入的认识。东中国海环流是由一个气旋式的“流涡”组成，东侧主要是北上的黑潮-对马暖流-黄海暖流及其延伸部分；西侧为南下的沿岸流系。黑潮对东中国海环流的影响是如此之大，以致于除了某些局部区域外，上述海域主要流系的冬、夏季分布形式比较相似而无本质上的差异(胡敦欣等，1993)。但本文所研究海域正处于世界上最显著的季风区，冬、夏季盛行风向基本相反，过渡季节(春、秋季)风向多变，风力减弱；海洋热盐结构季节变化明显(如冬季混合强，而夏季层化明显等)，这些因素都使得东中国海环流存在着较明显的季节变化。 自20世纪80年代以来，东中国海环流的数值模拟工作逐步展开，并已成为研究环流结构及其形成机制的强有力工具。但由于数值模式本身以及计算方案的缺陷(如有些学者用固定的风场、温盐场对东中国海环流进行诊断模拟等)和观测资料的不足，数值模拟的结果难以得到验证，渤、黄、东海的环流研究中仍有大量的问题存在争议，以待澄清。例如，台湾暖流的来源、流径;对马暖流的来源;夏季黄海暖流的流径以及黄海冷水团环流等均有不同的论述。对黄、东海环流季节变化的数值模拟工作也较少，多用冬、夏典型月份的风场强迫积分至稳定态，给出冬、夏季环流，这种做法值得商榷。三维环流模式很难在1个月内达到稳定态，尤其是夏季层化明显、风力减弱的情况下，非常定风场的影响更应引起人们的重视。 本文采用比较符合实际的计算方案，用年循环风场和海面热通量场为外强迫，对渤、黄、东海的环流及其季节变化进行了模拟，并对一些争议问题进行了探讨。     

南海的季节环流─TOPEX/POSEIDON卫星测高应用研究

应用1992～1996年的TOPEX/POSEIDON卫星高度计遥感资料,研究了冬、夏季风强盛期多年平均的南海上层环流结构。研究结果表明,南海上层流结构呈明显的季节变化,在很大程度上受该海区冬、夏交替的季风支配。冬季总环流呈气旋型,并发育有两个次海盆尺度气旋型环流;夏季总环流大致呈反气旋型、但在南海东部18°N以南海域未见明显流系发育。研究还表明,南海环流的西向强化趋势明显,无论冬、夏在中南半岛沿岸和巽他陆架外缘均存在急流,其流向冬、夏相反,是南海上层环流中最强劲的一支。鉴于该海流的动力特征与海洋动力学中定义的漂流不同,有相当大的地转成分,建议称为“南海季风急流(South China Sea MonsoonJet)”.冬季南下的季风急流在南海南部受巽他陆架阻挡折向东北,沿加里曼丹岛和巴拉望岛外海有较强东北向流发育。夏季北上的季风急流在海南岛东南分为两支:北支沿陆架北上,似为传统意义上的南海暖流;南支沿18°N向东横穿南海后折向东北;二者之间(陆架坡折附近)为弱流区。两分支在汕头外海汇合后,南海暖流流速增强。就多年平均而言,黑潮只在冬季侵入南海东北部,并在南海北部诱生一个次海盆尺度的气旋型环流,这时南海暖流只出现在汕头以东海域.夏季南海北部完全受东北向流控制,未见黑潮入侵迹象.用卫星跟踪海面漂流浮标观测进行的对比验证表明,以上遥感分析结果与海上观测一致。     

Processes influencing iron distribution in the coastal waters of the Tsugaru Strait,Japan

We report measurements of iron, nutrients, dissolved oxygen, humic-type fluorescence intensity and chlorophyll a concentrations in the coastal waters at the inflow (western) and outflow (eastern) ends of Tsugaru Strait (Japan) in June 2003 and 2004. Two different water masses (intensive eastward flow “subtropical Tsugaru Warm Current Water (TWCw)” and weak westward flow “subarctic Oyashio Water (OW)”) were observed at the eastern end of the strait. TWCw at the southern part of the eastern strait was vertically homogeneous with a uniform concentrations of iron (0.7–1.1 nM for labile dissolved Fe and 14–20 nM for total dissolvable Fe in 2003) as well as other chemical, biological and physical components throughout the water column of 200 m due to strong vertical mixing in the strait. The degree of mixing in the Tsugaru Warm Current (TWC) is predominantly affected by diurnal tidal current, which is strong during the period of tropical tides and weak during the period of equinoctial ones. The especially strong vertical water mixing in 2003 is caused by large dissipation energy input due to the bottom friction of passage-flow through the strait and tidal current. At the northern part of the eastern strait, the fresh surface layer overlying the OW and the deep-bottom waters in 2003 contained large concentrations of dissolved iron, resulting from iron supplied from river runoff and shelf sediments, respectively. These results suggest that the most important mechanism for transporting iron in the strait is the strong vertical water mixing due to the tidal current, and that the iron sources in the coastal waters are the organic-associated, iron-rich freshwater input into the surface water.     

数值实验论证台湾暖流和对马暖流的关系

台湾暖流和对马暖流均为沿中国东部海域大陆架的北向流。有学者认为存在"台湾-对马暖流流系"。现有的研究均未涉及台湾暖流和对马暖流在该系统中各自的动力作用。本文作者发现在该系统中对马暖流扮演更为重要的角色。借助一个三维斜压模式,作者设计了几组数值实验来讨论台湾暖流和对马暖流之间的动力学机制。结果显示台湾暖流对对马暖流几乎没有影响,而对马暖流却对台湾暖流存在重要影响。尽管对马暖流位于"下游区",通过"源-汇"驱动作用,其可以诱生约0.5×106m3/s的台湾暖流水。作者认为,能量通过地形波传导理论可能为这一动力学机制的合理解释。     

东海西部陆架海域水团的季节特征分析

On the basis of the CTD data and the modeling results in the winter and summer of 2009, the seasonal characteristics of the water masses in the western East China Sea shelf area were analyzed using a cluster analysis method. The results show that the distributions and temperature-salinity characteristics of the water masses in the study area are of distinct seasonal difference. In the western East China Sea shelf area, there are three water masses during winter, i.e., continental coastal water（CCW）, Taiwan Warm Current surface water（TWCSW） and Yellow Sea mixing water（YSMW）, but four ones during summer, i.e., the CCW, the TWCSW, Taiwan Warm Current deep water（TWCDW） and the YSMW. Of all, the CCW, the TWCSW and the TWCDW are all dominant water masses. The CCW, primarily characterized by a low salinity, has lower temperature, higher salinity and smaller spatial extent in winter than in summer. The TWCSW is warmer, fresher and smaller in summer than in winter, and it originates mostly from the Kuroshio surface water（KSW） northeast of Taiwan, China and less from the Taiwan Strait water during winter, but it consists of the strait water and the KSW during summer. The TWCDW is characterized by a low temperature and a high salinity, and originates completely in the Kuroshio subsurface water northeast of Taiwan.     

夏季台湾海峡水及黑潮次表层涌升水向东海近陆架区营养盐输送通量的估算

According to historical mean ocean current data through the field observations of the Taiwan Ocean Research Institute during 1991–2005 and survey data of nutrients on the continental shelf of the East China Sea(ECS) in the summer of 2006, nutrient fluxes from the Taiwan Strait and Kuroshio subsurface waters are estimated using a grid interpolation method, which both are the sources of the Taiwan Warm Current. The nutrient fluxes of the two water masses are also compared. The results show that phosphate(PO4-P), silicate(SiO3-Si) and nitrate(NO3-N) fluxes to the ECS continental shelf from the Kuroshio upwelling water are slightly higher than those from the Taiwan Strait water in the summer of 2006. In contrast, owing to its lower velocity, the nutrient flux density(i.e., nutrient fluxes divided by the area of the specific section) of the Kuroshio subsurface water is lower than that of the Taiwan Strait water. In addition, the Taiwan Warm Current deep water, which is mainly constituted by the Kuroshio subsurface water, might directly reach the areas of high-frequency harmful alga blooms in the ECS.     

The circulation in the southern Huanghai Sea and northern East China Sea in June 1999

On the basis of hydrographic data and current measurement (the mooring system, vessel-mounted ADCP and toward ADCP) data obtained in June 1999, the circulations in the southern Huang-hai Sea (HS) and northern East China Sea (ECS) are computed by using the modified inverse method. The Kuroshio flows northeastward through eastern part of the investigated region and has the main core at Section PN, a northward flow at the easternmost part of Section PN, a weaker anti-cyclonic eddy between these two northward flows, and a weak cyclonic eddy at the western part of Section PN. The above current structure is one type of the current structures at Section PN in ECS. The net northward volume transport (VT) of the Kuroshio and the offshore branch of Taiwan Warm Current (TWCOB) through Section PN is about 26.2×106m3/s in June 1999. The VT of the inshore branch of Taiwan Warm Current (TWCIB) through the investigated region is about 0.4×106m3/s. The Taiwan Warm Current (TWC) has much effect on the currents over the     

NotesBenthic foraminiferal distribution in surface sediments along continental slope of the southern Okinawa Trough: dependance on water masses and food supply

Benthic foraminiferal analysis of 29 samples in surface sediments from the southern Okinawa Trough is carried out. The results indicate that benthic foraminiferal abundance decreases rapidly with increasing water depth. Percentage frequencies of agglutinated foraminifera further confirm the modern shallow carbonate lysocline in the southern Okinawa Trough. From continental shelf edge to the bottom of Okinawa Trough, benthic foraminiferal fauna in the surface sediments can be divided into 5 assemblages: (1) Continental shelf break assemblage, dominated by Cibicides pseudoungerianus, corresponds to subsurface water mass of the Kuroshio Current; (2) upper continental slope assemblage, dominated by Cassidulina carinata , Globocassidulina subglobosa, corresponds to intermediate water mass of the Kuroshio Current; (3) intermediate continental slope assemblage, dominated by Uvigerina hispi-da, corresponds to the Okinawa Trough deep water mass above the carbonate lysocline; (4) lower continental slope- trough b     

基于1987-2010年实测资料对PN断面东海黑潮季节变化的分析

As the spatio-temporal variability of the Kuroshio is highly influenced by mesoscale eddies, representing its seasonal variability characteristics requires sufficiently long term observations to reduce...     

Numerical investigation on propulsion of the counter-wind current in the northern South China Sea in winter

The propulsion of the winter counter-wind current in the northern South China Sea (SCS) is investigated with a regional, three-dimensional, primitive equation model. This current is usually called the SCS Warm Current (SCSWC). Model results well reproduced the banded structure of the Guangdong coastal current, the SCSWC and the slope current from the coast to the slope in the northern SCS in the climatological data. The across-shelf flow is active in the shelf break area. Both onshore and offshore flows exist; the net across-shelf transport is shoreward throughout the year, and is larger in winter than in other seasons. The joint effect of baroclinicity and relief (JEBAR) is the dominant forcing of the across-shelf transport in the shelf break area. The major mass source of the SCSWC is the onshore-veered slope current. It is the JEBAR effect that supplies the necessary negative vorticity to maintain the slope current flowing across the isobaths and veering to the right hand to feed the SCSWC. Analyses of the momentum fields indicate that the onshore pressure gradient in the outer shelf balances the Coriolis force induced by the northeastward SCSWC in the frame of geostrophy. In winter, such an onshore pressure gradient is mainly provided by the strong density contrast between waters of the shelf and of the upper slope, which results from the Kuroshio intrusion via the Luzon Strait. The notable intrusion of the Kuroshio in winter is crucial for maintaining the density structure in the shelf break area and facilitates the set-up of the onshore pressure gradient over the outer shelf.     

冬、夏季东海北部悬浮体分布及海流对悬浮体输运的阻隔作用

依据1987年6月、1996年12月、1997年2月和1998年7月在东海北部所取得的悬浮体、温度和盐度资料就该区冬季和夏季的悬浮体分布、影响因素和输运进行了研究,结果表明该区悬浮体分布具有明显的季节性变化,在中、外陆架区悬浮体含量冬季明显高于夏季.悬浮体的分布及输运受到东海环流、风暴和潮流等的影响,其中东海环流的季节性变化是主要影响因素.受台湾暖流的阻隔,冬季和夏季长江入海泥沙在东海基本不能越过124°00'E以东海域.黄海沿岸流携带着老黄河口水下三角洲的再悬浮沉积物向陆架东南扩散,其搬运的量和在中、外陆架区的扩散范围冬季显著大于夏季.在黄海暖流的阻隔下,陆架悬浮体冬季和夏季在32°N断面很少能扩散至126°30'E以东海域.台湾暖流和黑潮爬升水的阻隔作用使得冬季和夏季陆架悬浮体在P-N断面也基本不能扩散至陆架边缘.冬季在东海北部可有部分陆架悬浮体输送到冲绳海槽,但有区域性,其输送的可能位置是在P-N断面以北、32°N断面以南之黄海沿岸流向东南延伸的陆架边缘;夏季陆架悬浮体基本滞留在陆架区.     

东海东北部夏季水文状况的研究

本文主要根据韩国海洋研究所通过东海沿岸海洋过程试验（即COPEX－ECS）收集的CTD资料,较详细地研究了东海东北部夏季的水文状况．文中首先分析了夏季出现在该海域最重要的几件海洋现象．其中主要包括长江冲淡水的东向扩展,黄海底层冷水南向插入,以及黑潮水的爬升和渗透。然后,使用t－S分析法,并参考有关研究成果,对东海东北部夏季水团进行了划分,并重点探讨了黑潮水和对马暖流水的结构特征。最后,本文讨论了朝鲜／对马海峡东、西水道夏季水文结构的差异问题。     

Benthic foraminiferal distribution in surface sediments along continental slope of the southern Okinawa Trough: dependance on water masses and food supply

Benthic foraminiferal analysis of 29 samples in surface sediments from the southern Okinawa Trough is carried out.The results indicate that benthic foraminiferal abundance decreases rapidly with increasing water depth.Percentage frequencies of agglutinated foraminifera further confirm the modern shallow carbonate lysocline in the southern Okinawa Trough.From continental shelf edge to the bottom of Okinawa Trough,benthic foraminiferal fauna in the surface sediments can be divided into 5 assemblages:(1) Continental shelf break assemblage,dominated by Cibicides pseudoungerianus,corresponds to subsurface water mass of the Kuroshio Current;(2) upper continental slope assemblage,dominated by Cassidulina carinata,Globocassidulina subglobosa,corresponds to intermediate water mass of the Kuroshio Current;(3) intermediate continental slope assemblage,dominated by Uvigerina hispida,corresponds to the Okinawa Trough deep water mass above the carbonate lysocline.     

Variability of the circulation in the southern Huanghai Sea and East China Sea during the two investigative cruises in June 1999

1IntroductionAlotofworkonthestudyofthecircula-tionintheHuanghai(Yellow)Sea(HS)andEastChinaSea(ECS)hasbeenmadeandreviewedbyscientists,suchasSu(1998),Suetal.(1994),Guan(1985),YuanandSu(1983,2000),Yuanetal.(1997,1988,1994,2001),Tangetal.(2000)andsoon.Inthispapertheseworks willnotbereviewedagainduetolimitationofpages.Thejointinvestigationontheair-seainteractionprocessofcycloneoutbreakoverthesouthernHuanghaiSeaandEastChinaSeawascarriedoutinthecooperativestudybytheChinese(in-clusiveofTaiwa…     

Recent advances in ocean-circulation research on the Yellow Sea and East China Sea shelves

Recent advances in ocean-circulation research on the Yellow Sea and East China Sea shelves are summarized. Observations using acoustic Doppler current profilers (ADCPs) suggest that the connectivity of mean-volume-transports is incomplete between the Tsushima (2.6 Sverdrups; 1 Sv = 10⁶ m³/s) and Taiwan Straits (1.2 Sv). The remaining 1.4-Sv transport must be supplied by onshore Kuroshio intrusion across the East China Sea shelf break. The Yellow Sea Warm Current is not a persistent ocean current, but an episodic event forced by northerly winter monsoon winds. Nevertheless, the Cheju Warm Current is detected clearly regardless of season. In addition, the throughflow in the Taiwan Strait may be episodic in winter when northeasterly winds prevail. The throughflow strengthens (vanishes) under moderate (severe) northeasterly wind conditions. Using all published ADCP-derived estimates, the throughflow transport (V) in the Taiwan Strait is approximated as