冬季东海黑潮上层水变化特征的分析

东海黑潮水团是东海海域的主要水团。夏季,东海黑潮水团一般划分为四层结构:黑潮表层水、黑潮次表层水、黑潮中层水和黑潮深层水。在冬季,由于大陆沿岸水系势力减弱,以及强烈的表层冷却产生的垂直对流作用,使黑潮表层水变性而和次表层水融为一体,从而使海面至400米层左右的黑潮水体呈现高盐特征。因此,冬季的东海黑潮水团变为三层结构,即黑潮上层水、黑潮中层水和黑潮     

台湾以北黑潮水与陆架水的混合与交换

本文根据日本气象厅在台湾以北获得的调查资料及近几年国家海洋局在该海域获得的调查资料,结合卫星图片,分析了夏季和冬季台湾以北海域陆架水与黑潮水的混合与交换过程以及涡旋在水交换过程中所起的作用。结果表明,夏季陆架水从表层向外海方向扩展,与黑潮水进行混合与交换;在陆架底部,黑潮次表层水涌升陆架后与陆架底层水进行混合。冬季由于黑潮表层水大举入侵陆架,低温的陆架水只能沿陆架向南流动,并在台湾西北部转向东沿台湾北岸向东流动,该海域存在的涡旋就象一个旋转泵,在陆架水与黑潮水的混合与交换过程中起了重要的作用。最后,文中还对陆架水与黑潮水的交换量进行了估算。     

1984年夏季东海水团的聚类分析

利用Q型聚类分析中的夹角余弦法,以相似矩阵为主要依据,对1984年夏季东海82个大面温盐测站,进行了水团的聚合归类。仅表层就二级分割为5个水团:黑潮表层水,台湾暖水表层水,大陆沿岸水,东海陆架变性水和黄海表层混合水。表层之下的水团类型与其上类似。该结果与T-S图解和地转流法获得的结果吻合良好,表明本文引用的方法是可行的。     

东海南部水系分布和季节变化特征

利用中日黑潮联合调查研究期间“实践”号船１９８７年夏、冬季、,１９８８年春、秋季的实测资料对研究海域的水系分布及其季节变化进行了分析研究。研究结果表明：（１）与大陆沿岸水性质相近的Ⅳ类混合水秋、冬季分布在大陆沿岸、春、夏季的范围向外海扩展。（２）黑潮水与陆架混合水的边办位置（称为黑潮水左边界）大致位于１００－２００ｍ等深线之间,并随季节摆动,台湾东北海域,春季黑潮水边界靠达１００ｍ等深线,夏季靠近     

黄、东海毗邻海域悬浮体与水团的对应关系及影响因素

对黄、东海毗邻海域由陆架到深海的悬浮体进行了大量加密取样,获得了较准确的结果。给出了悬浮体含量及其三维分布,确定它们与水团及其边界有良好的对应关系。并从物源、动力和成因等解释了这种对应,提出了水团对悬浮体研究的重要意义。研究表明黑潮次—中层混合爬升水及其混合水形成悬浮体含量最低值区,横亘在陆架与深海之间,形成阻隔含有大部分悬浮体的陆架中、下层水体向深海输送的洁净“水障”,台湾暖流北上的顶托也起类似作用,并分析了影响悬浮体含量的各种因素及有关机制。     

东海黑潮锋面涡旋在陆架水与黑潮水交换中的作用

根据NOAA卫星红外影像和水文、化学、生物的观测资料,分析了黑潮锋面涡旋中的黑潮水向陆架一侧倒卷,陆架混合水被卷入黑潮,以及深层富营养盐水被泵吸到上层海洋的基本形态。分析表明黑潮锋面涡旋在陆架水与黑潮水的交换中起十分重要的作用。本文对3个锋面涡中的水交换量进行计算得到:卷入到黑潮中的陆架混合水平均为0.44×105m3/s,而进入陆架的倒卷黑潮暖水仅为0.04×106m3/s.对于整个东海陆架边缘,锋面涡作用可使1.8×106m3/s的陆架混合水卷入黑潮。在锋面涡存在情况下,被泵吸到真光层并向陆架方向输运的NO₃-N,其单宽输运量为974μmol/(m·s),而无锋面涡存在时仅为79μmol/(m·s).锋面涡造成的陆架方向的NO₃-N输运量为1.7×105t/a.     

诺阿卫星红外信息数字化反差增强图象中东海表层水系配置的解译

前言 长期以来,海洋学界为阐明黑潮与陆架水的混合机制,长年累月进行着现场调查与研究。本文在此提出应用卫星红外信息,能够直观、快速、大范围和同步获取作为其中一个主要环节的表层水系配置。这至少对东海表层水来说,进一步认识对马暖流及其分支黄海暖流的主体是源于黑潮水系和陆架水的混合水,而不是日本九州西南海域分出来的黑潮水,有着重要的意义。     

应用对应分析法划分夏季东海水团的初步研究

本文综合分析四个断面16个标准层的因子点聚,表明在整个海区有九个水团,即:黑潮表层水、黑潮次表层水、黑潮中层水、黑潮深层水、大陆沿岸水、台湾暖流水、黄海水、对马暖流水和东海混合水,前6个水团是该海区的主要水团。本文还详细讨论了每个水团的分布特征。     

东海东北部春季若干重要水文结构的分析

本文主要基于韩国海洋研究所在东海沿岸海洋过程试验中收集的ＣＴＤ资料，分析了１９９５年春季出现在东海东北部的一些重要水文结构。结果表明，一种锋涡状结构出现在黑潮向东转折点附近。它不仅使邻近海域的水文结构变得更复杂，而且诱发黑潮水与陆架水间活跃的交换。在陆架坡折处观测到若干孤立的陆架水块，可能是锋涡的卷挟作用所致；该海域存在４个水团，即黑潮水、对马暖流水、陆架水和混合水。对马暖流水分为上下两层：上层水为变性黑潮水，盐度比黑潮水约低０．１，底层对马暖流水仅位于冲绳海槽区，并有着与黑潮中层水相同的温、盐特性；一种双锋结构出现在邻近黑潮的陆架边缘附近。在内陆架形成的陆架锋，由北向南伸展时，愈来愈偏向陆架边缘。而黑潮锋沿九州以西深槽的陆架边缘向北伸展。在黑潮转折点附近，两锋几乎合并为一条锋。狭窄的锋带由黑潮水及其变性水和陆架水的混合水所占据。     

模糊目标函数聚类算法及其在东海黑潮水团分析中的应用

由于受陆架海区气候、海底地形等影响,使东海黑潮及其邻近海域的水团划分与分析较为困难,本文应用模糊目标函数的聚类算法对这个海区的水团进行了划分与分析,文中详细地叙述了这种算法的基本原理与计算步骤,包括对原始样本资料进行加权处理,利用Fuzzy伪F统计比率选择子模式样本确定水团个数和利用隶属度公式确定水团边界以及逐步修正模糊协方差矩阵和聚类中心的过程,由于采用这种方法,该海域的水团得到了一种最佳的划分.本文采用1986年5、6月中日合作黑潮调查资料进行计算,计算结果表明,本海区存在属于两种基本类型的8个水团和一个混合区,它们是:一、黑潮水:1.黑潮表层水(K_f);2.黑潮次表层水(K_s);3.黑潮中层水(K_c).二、混合水:1.东海混合水(E);2.福建东北部海域混合水(F_em);3.黄海上层混合水(Y_f);4.对马暖流表层水(T_suf);5.屋久岛南部海域表层水(U_f),此外,有一个混合区(M_k).     

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     

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.     

Upward transport of iron at the west shelf edge–slope of the Okinawa Trough in the East China Sea

We studied the behavior of chemical substances in the upper 300 m of the water column across the continental shelf–slope interface in the East China Sea off the Okinawa Trough. The behaviors of iron, inorganic nutrients, and humic-like fluorescent dissolved organic matter were strongly influenced by the extensive water exchange between the East China Sea and the Kuroshio Current across the shelf break and slope via upwelling and frontal processes. We attributed the high humic-like fluorescent intensity at the subsurface of the shelf break and slope regions to the lateral supply of humic-like fluorescent dissolved organic matter from the shelf sediments to the outer shelf region due to the intrusion of shelf water into Kuroshio subsurface water. We found that the behavior of iron at the continental shelf–slope was remarkably different from the conservative mixing of inorganic nutrients and humic-like fluorescent dissolved organic matter. In deep and bottom waters at the shelf–slope, high total iron concentrations, which were closely related to water transmittance, possibly resulted from the swept transport of iron-rich resuspended sediments over the shelf floor from the slope by the invading Kuroshio Intermediate Water close to the bottom.     

台湾东北部黑潮次表层水入侵的季节变化规律

台湾东北部,黑潮次表层水常年入侵东海陆架。但是黑潮次表层水入侵的季节变化规律,尚存在很多不明之处。本文基于2009至2011年间东海4个航次的CTD实测数据,研究了黑潮次表层水入侵东海过程的季节变化规律,发现:黑潮次表层水入侵在春末夏初开始加强,夏季最强,秋季开始减弱,冬季最弱。入侵的黑潮次表层水起源深度也随季节变化有所不同。另外,结果还表明黑潮次表层水入侵存在明显的短期变动。     

Characteristics of summer and winter circulations and their variability in the source area of the Tsushima Warm Current

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The characteristic distribution of silica over the East China Sea shelf slope

The localized near-bottom water with silica content higher than that in the adjacent shelf water was observed to exist at the eastern margins of the East China Sea continental shelf. The core of the high silica water possessed the silica content corresponding to that in the Kuroshio at depths greater than on the shelf. The mixing analysis of water masses using temperature (T) and silica (Si) showed that the core water can be produced through the vertical mixing of intermediate water of the Kuroshio deeper than 100 m. This study provides us a conclusion that the intermediate water of the Kuroshio is strongly mixed on the shelf slope and then upwelled to form the ridge-like distribution of water masses with low temperature and high silica content at the shelf edge.     

秋季东海黑潮锋面涡旋的特点

本文根据１９８８年１０月２０～２４日“向阳红０９号”调查船在奄美大岛以西海区进行调查时，在陆架斜坡上的表均温层的底部，即５０ｍ附近的深层上，出现一个黑潮锋面涡。不论在平面上形成的特点，还是在断面上水系配置的形式，它与春季黑潮锋面涡的特征极为相似。说明秋季东海同样存在陆架水与黑潮水在水平方向交换与混合。     

Role of Kuroshio frontal eddy in exchange between shelf water and Kuroshio water in East China Sea

Basic patterns of the reversal of the Kuroshio water toward the shelf, intrusion of the shelf mixed waterinto the Kuroshio and uplifting of the near-bottom nutrient-rich water into the upper layer by the pumping of the frontal eddy are analyzed on the basis of satellite infrared images and hydrologic, chemical and biological observations. Results show that the Kuroshio frontal eddies play a very important role in the exchange between the shelf water and the Kuroshio water. The estimation of the average volume transports for three frontal eddy events indicates that the shelf mixed water entrained by an eddy into Kuroshio is 0.44×10~6 m3/s and the reversal Kuroshio water onto the shelf region only 0.04×10~6 m3/s. Along the whole shelf edge, the volume transport of the shelf mixed water entrained by the eddies into the Kuroshio is 1.8×10~6 m3/s. The nutrient (NO3-N) flux pumped to the euphotic zone and input to the continental shelf through a column with 1 m wide is 974 μmol/(s·m) when there is frontal eddy and only 79 μmol/(s·m) in the case of no frontal eddy. Yearly nutrient (NO3-N) flux input to the shelf area caused by the frontal eddy is 1.7×10~5 t/a.     

Characteristics of outer shelf water in the East China Sea

Water mass properties along cross-sections of the Kuroshio in the East China Sea (ECS) are investigated in detail. We used temperature, salinity and dissolved oxygen data from 2000 and 2002, together with historical temperature and salinity data from 1987 to 2004. Water properties were divided into two groups: high and low salinities or oxygen at temperatures warmer than 15 and 12 °C, respectively. We found the existence of outer shelf water W2, as defined by clear modes in frequency distributions of salinity and oxygen within various temperature segments. The outer shelf water was different from both Kuroshio Tropical Water (KTW) and coastal water. We mapped horizontal and vertical distributions of W2, along with W1 and KTW. The outer shelf water was distributed with density σ _t = 22.5–25.5 over a relatively broad area, from the outer continental shelf to the continental slope, particularly in autumn. Vertical distribution of the water suggests that W2 spread from the outer shelf to just the shelf side of the Kuroshio Current velocity maximum. Seasonal variations are examined with historical data along PN section over 17 years, and suggest that the appearance of W2 is distinct in summer and autumn. By comparing temperature–salinity (T–S) diagrams from Taiwan Strait and east of Taiwan, the outer shelf water (W2) originates from South China Sea Tropical Water (SCSTW), as suggested by Chen, J Geophys Res 110:C05012 (2005). The present study of the ECS clearly shows that SCSTW is transported along the east coast of Taiwan or through the Taiwan Strait into the ECS. It then spreads over a relatively wide area from the outer shelf to just the shelf side of the Kuroshio axis, and there is some horizontal mixing between SCSTW and KTW around the shelf break.