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1.
Estimation of eddy viscosity on the South China Sea shelf with adjoint assimilation method 总被引：2，自引：0，他引：2
The eddy viscosity of the ocean is an important parameter indicating the small-scale mixing process in the oceanic interior water column.Ekman wind-driven current model and adjoint assimilation technique are used to calculate the vertical profiles of eddy viscosity by fitting model results to the observation data.The data used in the paper include observed wind data and ADCP data obtained at Wenchang Oil Rig on the SCS (the South China Sea) shelf in August 2002.Different simulations under different wind conditions are analyzed to explore how the eddy viscosity develops with varying wind field.The results show that the eddy viscosity endured gradual variations in the range of 10-3-10-2 m2/s during the periods of wind changes.The mean eddy viscosity undergoing strong wind could rise by about 25% as compared to the value under weak wind. 相似文献
2.
东海陆架环流季节变化的模拟与分析 总被引：12，自引：2，他引：10
在改进POM模式基础上,建立1个中国东部海域斜压准预报模式,利用全球海洋模式结果并结合实测资料以及高精度卫星遥感SST资料,进行了东海陆架海域温盐及环流年循环的数值模拟,并系统分析了东海陆架环流系统及其季节变化、各暖流的路径等广为关注的问题。模式结果表明：黑潮主轴主体沿陆架坡折走向,中段黑潮流幅由南至北增宽,流速变大,流核所达深度变浅。浙闽沿岸流是一典型的季风环流,台湾暖流终年表现出东、北两分支结构,其分支表现出明显的季节性变化特征。在东海东北部陆架海域,冬季黑潮以其分支形式向北入侵,夏季则主要以大陆边缘流的形式向北进入陆架。论文对各暖流的水源也进行了相应的分析。 相似文献
3.
本文通过二维数值模拟对1986年6月～1988年12月东海对马暖流水的来源问题进行了初步探讨,结果得出东海对马暖流水的来源基本上分为三种类型:(1)东海对马暖流水主要为东海黑潮水继续北上部分构成;(2)东海对马暖流水由东海黑潮水、东海陆架水以及东海北部黄海大陆沿岸水几部分混合而成;(3)东海对马暖流水几乎全部由东海北部的黄海大陆沿岸水构成。模拟与实测结果基本一致. 相似文献
4.
Osamu Katoh Kazuyuki Teshima Osamu Abe Hitoshi Fujita Kuniaki Miyaji Kenji Morinaga Norihisa Nakagawa 《Journal of Oceanography》1996,52(4):491-507
In order to clarify detailed current structures over the continental shelf margin in the East China Sea, ADCP measurements were carried out in summers in 1991 and 1994 by the quadrireciprocal method (Katoh, 1988) for removing diurnal and semidiurnal tidal flows from observed flows, together with CTD measurements. We discussed the process of the Tsushima Current formation in the East China Sea. The Tsushima Current with a volume transport of 2 Sv (1 Sv=106 m3s–1) was found north of 31°N. A current with a volume transport of 0.4 Sv was clearly found along the 100 m isobath. Between the Kuroshio and the current along the 100 m isobath, southeastward component of velocity was dominant compared to northwestward one. Four eastward to southeastward currents were found over the sea bed shallower than 90 m depth. Total volume transport of these four currents was 1 Sv, and they seemed to be originated from the Taiwan Strait. Intrusion of offshore water into the inner shelf northwest of Amami Oshima was estimated to have a volume transport of 0.6 Sv. It is concluded that the Tsushima Current is the confluence of these currents over the continental shelf margin with the offshore water intruding northwest of Amami Oshima. 相似文献
5.
Toshimichi Ito Arata Kaneko Hirohito Furukawa Noriaki Gohda Wataru Koterayama 《Journal of Oceanography》1995,51(3):267-278
The ADCP on an advanced towed fish with controllable main and tail wings, called DRAKE measured a detailed sectional structure of the Kuroshio flowing to the NE along the East China Sea shelf slope west of Okinawa. At the observation period, a countercurrent directed to the SW formed in near-bottom water on the shelf slope. The horizontal flow perpendicular to the stream axis of the Kuroshio constructed a convergence zone around the boundary between the Kuroshio and the countercurrent. An intensive upwelling with the maximum velocity of 2.8 cm s–1 was found to distribute on the shelf slope around the convergence zone. A dynamic cause of this intensive upwelling is discussed carefully. 相似文献
6.
渤、黄、东海内潮的数值模拟 总被引：2，自引：0，他引：2
在全球的海洋中,中国东海和临近海域是最显著的内潮生成地之一。本文采用NODC(Levitus) World Ocean Atlas 1998提供的季平均温、盐资料,计算海水的密度,并计算垂向密度梯度的最大值点,得到一个较符合海水实际的密度分层。使用三维非线性数值模型(将海洋分为2层)研究了潮汐(M2,S2,K1,O1分潮)作用下渤黄东海的内潮,揭示了整个海区内潮起伏的空间分布,结果发现大振幅的波动均发生在台湾东北(冲绳海槽)海域和中国近海地形突变之处,其中前者更显著。对于各分潮模拟得到的表面潮与TOPEX/Poseidon高度计资料基本一致。研究结果表明上层海水的深度和厚度的梯度对内潮有一定的影响;冬季分布区域比夏季小,强度比夏季大。 相似文献
7.
中更新世以来东海陆架的古环境 总被引：12，自引：4，他引：12
基于１９９６年中法合作在东海陆架进行的电火花单道地震调查资料,并与位于东海外陆架钻孔ＤＺＱ４对比,发现对应于氧同位素６期以来的六个地震地层与钻孔地层呈现很好的对应关系,其间共有四次海退－海进的沉积旋回。资料分析表明东海第四纪环境演变与全球气候冷暖变化所导致的海面升降直接相关。 相似文献
8.
《Ocean Modelling》2011,40(3-4):386-404
The aim of this paper is to assess the impact of numerical resolution on the simulation of the circulation in the North-Western Mediterranean Sea by comparing two realistic model configurations of 1/64° and 1/16°, the low resolution configuration (LRC) being also used at the high resolution configuration (HRC) open boundaries. The study mainly focuses on the Northern Current (NC), the major feature of the regional circulation in the area, influencing important processes such as meanders giving birth to eddies and NC intrusions on the shelf, strongly conditioning the interactions between coastal and off-shore waters. Both configurations use the NEMO code with the LRC covering the entire Mediterranean basin and the HRC being restricted to the North-Western Mediterranean Sea. The two numerical configurations are assessed by using hull-mounted ADCP data and geostrophic velocities derived from AVISO altimetry at key locations along the NC path. The two configurations develop a different solution regarding the current dynamics but both indicate an important variability of the NC position along its general path. The LRC simulations systematically exhibit a NC shifted too far off the coast and also spuriously displaced seaward along the Gulf of Lions shelf edge while high resolution simulations better fit the remote and in situ observations. In addition, the HRC is able to simulate more realistic coastal features such as a confined coastal jet in good agreement with the ADCP measurements. As satisfactory agreement is reached with the various observations used at different space and time scales, the development of this NEMO high resolution configuration stands as a promising experiment for various process studies or operational oriented applications. 相似文献
9.
海啸波传播的线性和非线性特征及近海陆架效应影响的数值研究 总被引：3，自引：2，他引：1
浅水方程被广泛应用于海啸预警报业务及研究,而针对线性浅水方程与非线性浅水方程在不同海区水深地形条件下的适用范围、计算效率问题是海啸研究人员急需了解的。本文应用基于浅水方程的海啸数值预报模型就海啸波在南海、东海传播的线性、非线性特征以及陆架对其传播之影响进行了数值分析研究。海啸波在深水的传播表征为强线性特征,此时线性系统对海啸波幅的模拟计算具有较高的精度和效率,而弱的非线性特征及弱的色散特征对海啸波幅的预报影响甚微,可以忽略不计。海啸波传播至浅水大陆架后受海底坡度变化、海底粗糙度等因素影响,波动的非线性效应迅速传播、积累,与线性浅水方程计算的海啸波相比表现出较大差异,主要表现为:在南海区,水深小于100m时,海啸波首波以后的系列波动非线性特征比较明显,两者波幅差别较大,但首波波幅的区别不大,因此对于该区域在不考虑海啸爬高的情况下,应用线性系统计算得到的海啸波幅也可满足海啸预警报的要求;在东海区由于陆架影响,海啸波非线性特征明显增强,水深小于100m区域,首波及其后系列波波幅均差异较大,故在该区域必须考虑海啸波非线性作用。本文就底摩擦项对海啸波首波波幅的影响进行了数值对比分析,结果表明:底摩擦作用对海啸波首波波幅影响仅作用于小于100m水深。最后,该文通过敏感性试验,初步分析了陆架宽度及陆架边缘深度对海啸波波幅的影响,得出海啸波经陆架传播共振、变形后,海啸波幅的放大或减小与陆架的宽度及陆架边缘水深有关。 相似文献
10.
东海陆架西部凹陷带古新统砂岩锆石的U-P年龄表明,陆架西部古新世物源以中生代母岩为主,其次为元古代变质岩及少量古生代母岩。东海陆架东部凹陷带渐新统砂岩锆石的U-P年龄表明陆架东部渐新世物源以元古代变质岩为主,其次为中生代母岩及少量太古代变质岩与古生代母岩。陆架西部古新统砂岩锆石的U-P年龄与闽浙隆起带露头及钻孔揭示的基岩一致,而陆架东部渐新统砂岩锆石的U-P年龄比西部老。根据上述砂岩锆石U-P年龄,可以推测古近纪东海陆架盆地发育过程中,东海陆架东部地势较高。单颗粒锆石REE配分模式表明元古代锆石轻稀土(LREE)明显比其他样品高且含量相近,Ce正异常不明显;中生代锆石Ce正异常明显,但同时Eu负异常也很明显,与中生代基岩锆石相似;古生代锆石稀土元素含量偏低,La含量明显超过其他轻稀土元素。根据上述特征可以清晰指示砂岩的母岩类型与年代,推断古新世东海大陆架的基底性质与构造背景。 相似文献
11.
In-Seong Han Koichiro Kamio Takeshi Matsuno Atsuyoshi Manda Atsuhiko Isobe 《Journal of Oceanography》2001,57(2):235-249
Relation between internal waves with short time scale and density distribution near the shelf break in the East China Sea is studied utilizing moored current meters, thermometers and conductivity-temperature-depth (CTD) casts. A well developed pycnocline was frequently observed around 150–200 m depth near the shelf break accompanied with the development of internal waves with short time scale. During the cruise in May 1998, the intensified internal wave motion with short time scale and the distinct offshore flow were observed just below the lower pycnocline, which shoaled and extended above the shelf area. It is suggested that vertical mixing generated by amplified internal waves would produce cross-shelf ageostophic density current around the pycnocline. During the cruise in May 1999, on the other hand, the lower pycnocline was located offshore below the shelf break, and the internal wave motion was amplified just above the lower pycnocline. In this case, the offshore flow should be generated above the lower pycnocline, but vertical profiles of current velocity were not obtained because acoustic Doppler current profiler (ADCP) data were not available around the lower pycnocline. 相似文献
12.
Yanpei Zhuang Yangjie Li Xizhen Liu Shichao Tian Bin Wang Zhongqiang Ji Haiyan Jin Jianfang Chen 《海洋学报(英文版)》2023,42(1):103-108
Here, we report the results of high-resolution nitrate measurements using an optical nitrate profiler(in situ ultraviolet spectrophotometer, ISUS) along transect across a high-turbidity shelf(East China Sea) and a lowturbidity shelf(Chukchi Sea). The ISUS-measured nitrate concentrations closely reproduced the results measured by conventional bottle methods in low-turbidity waters. However, for high-turbidity waters of the East China Sea(salinity<30), a correction factor of 1.19 was required t... 相似文献
13.
东海陆架水文浊度要素自动采集系统设计 总被引：2，自引：1，他引：1
提出了一种利用四脚架体原位观测东海陆架区域水文、浊度要素的方法,通过数据采集单元,实现对测量要素的采集和存储。通过对获取数据的分析,表明该方法安全可靠,可为揭示东海内陆架沉积过程研究提供数据来源。 相似文献
14.
黑潮与邻近东海生源要素的交换及其生态环境效应 总被引：2，自引：0，他引：2
黑潮与东海生源要素的交换对东海的生态环境有重大影响,交换主要是经台湾东北部海域输送至东海陆架和通过日本九州西南海域由东海陆架向外海的黑潮输出两个通道。中国科学院海洋先导专项对黑潮与邻近东海生源要素的交换特征进行了系统的调查和研究,获得了一些新的认识:(1)在台湾东北部区域,碳主要以表层水-次表层水为载体输入,秋季的输入量高于夏季;黑潮溶解态营养盐的输入占据绝对主导地位,且以黑潮次表层热带水-中层水的输入为主,输入通量春季高于夏、秋季,可为东海春季水华提供一定的物质基础,但输入到东海的黑潮水其氮磷比与Redfield比值(16:1)接近,这些"正常水"——黑潮的输入显然对调和东海异常高的氮磷比有重要的作用,从而对东海的生态环境起到"稳定和缓冲"作用。所以,黑潮水对东海的输入不仅维持补充了东海生态系统运转所需的生源要素,更为重要的是缓冲了受人为影响强烈的东海海水的高氮磷比,使东海本已失常的营养盐结构向合适的氮磷比方向转变。因此,黑潮与东海生源要素的输入在一定程度上起着稳定和缓和东海生态环境的作用。(2)通过构建的海水Ba-盐度新指标体系,定量细致刻画了黑潮对东海生源物质在台湾东北部区域的输入范围和程度,黑潮次表层水从台湾东北陆架坡折处沿底部向北偏西方向入侵东海,其近岸分支可以入侵到浙江近岸,其黑潮次表层水占比仍可达到65%左右。垂直方向上,陆架外侧站位受黑潮次表层水的影响范围更大,黑潮水占50%比例位置可延伸至外侧TW0-1站位(122.59°E,25.49°N)表层,而内侧靠近大陆的站位则只限于陆架中部位置底层。 相似文献
15.
ＩＮＴＲＯＤＵＣＴＩＯＮＲｅｃｅｎｔｙｅａｒｓ’ｓｔｕｄｙｈａｓｐｒｉｍａｒｉｌｙｓｈｏｗｎｔｈａｔｔｈｅＳＣＳｈａｓａｎｉｍｐｏｒｔａｎｔｉｎｆｌｕｅｎｃｅｏｎｔｈｅｍｏｎｓｏｏｎｃｕｒｒｅｎｔｓａｎｄｏｎｔｈｅｆｌｏｏｄａｃｔｉｖｉｔｉｅｓｏｃｃｕｒｒｅｄｉｎｔｈｅｒｅｇｉｏｎｏｆＣｈｉｎａ (Ｓｕｎｅｔａｌ .,1 999,Ｄｉｎｇｅｔａｌ.,1 999) .ＴｈｅｍｏｎｓｏｏｎｏｎｓｅｔｉｎｅｖｉｔａｂｌｙｃａｕｓｅｓｔｈｅａｄｊｕｓｔｍｅｎｔｏｆｔｈｅＳＣＳｃｉｒｃｕｌａ ｔｉｏｎ ,ａｎｄｉｎｔｕｒｎ ,ｔｈ… 相似文献
16.
《Oceanologica Acta》1998,21(5):713-716
Exchanges between the East China Sea (ECS) and the Kuroshio have been recalculated by taking into consideration the intra-annual variation of salinity on the shelf. Flux through the Taiwan Strait, previously unavailable data in the Yellow Sea and in the central and northern ECS, denitrification and ground water fluxes are now also considered. The Kuroshio Intermediate Water remains the major source of nutrients on the East China Sea continental shelf, with slightly more upwelling in the dry season than in the wet season. 相似文献
17.
1989年东海陆架水团及高密水环流的季节变化 总被引：3，自引：1，他引：3
本文利用１９８９年的观测资料，分析了水团及高密水环流的季节演变特征。结果表明：东海高密水在陆架上存在一个季节性的变化过程，核心区有一个气旋型的密度环流；这个环流秋、冬季较弱，春、夏季较强；在该环流的产生过程中，它可以影响邻近水团的分布；在春季，邻近水团在东海高密水周围形成一个环状分布 相似文献
18.
研究南海环流的方法很多,采用GDEM资料,运用P矢量方法,得出了南海春季、夏季局部的上层流场分布情况.通过分析并结合UCM-60超声海流计和ADCP走航式测流仪相关实测数据,初步验证了这种研究南海上层季节环流所用的数值计算方法. 相似文献
19.
青藏高原的强烈隆起始于第四纪初期，目前仍处于强烈隆起阶段。根据钻孔和浅地层剖面仪测量等大量资料的研究，更新世以来东海陆架的周边也处于快速隆起时期，冰期海退时期的地壳回弹作用有可能加大了东海陆架区的地壳上升量。 相似文献
20.
海水碳酸盐体系参数是反映碳循环调控机理和季节性酸化过程的重要海水化学参数.本文根据2011年3月、7月、11月和12月4个不同季节航次获取的长江口海域海水碳酸盐体系参数,探讨了长江口-东海P断面溶解无机碳(DIC)和总碱度(T A)的空间分布特征及其影响因素.结果表明:内陆架区,DIC和T A的平均值均表现为:夏季<秋季<冬季<春季;垂直分布上,夏季和秋季受长江冲淡水影响出现层化现象,春季和冬季均垂直混合较均匀.东海内陆架DIC与温度和DO呈显著负相关;T A则受温度和DO变化影响较小,与盐度呈正相关.结合2011年东海外陆架的PN断面数据分析,DIC和pH分别与表观耗氧量(AOU)呈显著正相关和负相关,东海外陆架的pH/AOU的斜率为-0.0027 pH/(μmol·kg-1);而内陆架区的pH/AOU的斜率为-0.0018 pH/(μmol·kg-1),低于黑潮次表层水中pH/AOU的斜率.东海内陆架区由于存在季节性的通风作用以及较强的海水碳酸盐体系缓冲能力,底层水体中因有机质耗氧降解导致的季节性酸化信号在一定程度上得到了缓解. 相似文献