共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
伊豆海脊两侧顺时针流涡的若干观测证据 总被引:1,自引:0,他引:1
本文对方国洪等(1995)有关“西北太平洋环流三维结构的计算结果中显示出当黑潮越过伊豆海脊时,由于海脊的阻塞作用,在伊豆海省两侧出现两个顺时针流涡”的论术,提出若干观测和文献的证据,证实这两个流涡是存在的;还对这些流涡的机理作了初步的分析。 相似文献
3.
On Structure and Temporal Variation of the Bifurcation Current off the Kii Peninsula 总被引:1,自引:0,他引:1
Makoto Uchida Junichi Takeuchi Yoshitaka Morikawa Youichi Maekawa Osamu Momose Takashi Koike Yutaka Nagata 《Journal of Oceanography》2000,56(1):17-30
The Kii Bifurcation Current is often found along the southwest coast of the Kii Peninsula, and its frequency of occurrence reaches about 70% in the period from 1988 to 1996 (Takeuchi et al., 1998a). In order to clarify the structure and short-period variability of the Kii Bifurcation Current, detailed observations were made four times on board the R/V Seisui-maru of Mie University on October 29–31, 1996, on June 24–26, 1997, October 14–16, 1997, and December 3–4, 1997. The measured horizontal structure of the Kii Bifurcation Current indicates that the eastern portion of the Current (eastward flow near Cape Shionomisaki) consists of a part of the current zone of the Kuroshio. It is shown that the current structure, including the Kii Bifurcation Current in the vicinity of Cape Shionomisaki, is stable when the Kuroshio is flowing in a stationary straight path, but that the current structure is considerably changed when small-scale eddies pass by the cape. Such short-period variation can be monitored by using the daily variation of the sea level difference between Kushimoto and Uragami. In particular, in the case of October 29–31, 1996, when an eminent small-scale eddy passed by Cape Shionomisaki, and when the Kuroshio axis tentatively moved southwards about 50 km apart from the coast, the Kii Bifurcation Current seems to have disappeared. 相似文献
4.
5.
From frequent field observations performed in coastal waters around the Izu Islands, Japan, a clear regional upwelling associated with the wind was detected baside Niijima Island. Nutrient supply by the upwelling into the euphotic zone was confirmed, and the subsequent phytoplankton growth supported by the upwelled nutrients was evaluated. The upwelling and the nutrient supply occurred within a day over an area ofca. 400 km2, and phytoplankton growth response occurred only a few days after the upwelling. Such regional upwelling is considered to be one of the major mechanisms supporting the high productivity of coastal waters.Contribution number 423 from the Shimoda Marine Research Center, University of Tsukuba. 相似文献
6.
渤海对辽东半岛大暴雨影响的数值试验 总被引:1,自引:0,他引:1
运用MM5V3.5模式成功模拟了辽东半岛2004年8月3日的大暴雨过程,并模拟出了产生大暴雨的中尺度低压.敏感性试验比较了渤海、沙漠、城市和地形高度产生的地面温度、湿度、不同高度的水平风速、垂直速度的变化,研究了不同下垫面造成的边界层结构特征和局地环流,揭示出渤海和辽东半岛地形使降水大幅度增强.湿位涡诊断分析表明,此次大暴雨是在低层强对流不稳定和斜压不稳定条件下发生的,改变渤海地表和降低辽东半岛地形高度都使低层不稳定减弱. 相似文献
7.
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... 相似文献
8.
A Review on the Currents in the South China Sea: Seasonal Circulation, South China Sea Warm Current and Kuroshio Intrusion 总被引:43,自引:4,他引:43
Researches on the currents in the South China Sea (SCS) and the interaction between the SCS and its adjacent seas are reviewed. Overall seasonal circulation in the SCS is cyclonic in winter and anticyclonic in summer with a few stable eddies. The seasonal circulation is mostly driven by monsoon winds, and is related to water exchange between the SCS and the East China Sea through the Taiwan Strait, and between the SCS and the Kuroshio through the Luzon Strait. Seasonal characteristics of the South China Sea Warm Current in the northern SCS and the Kuroshio intrusion to the SCS are summarized in terms of the interaction between the SCS and its adjacent seas. 相似文献
9.
吕宋海峡是南海与外界水交换的重要通道,黑潮作为北太平洋最强的1支西边界流,在经过吕宋海峡时会对南海北部的环流和环境产生重要影响。本文用1991—2011年期间CTD断面实测资料和高度计资料,提取23.0~25.5 kg/m3等密度面之间的盐度极大值,研究了南海北部不同年月盐度极大值变化、黑潮入侵方式与强弱,以及盐度极大值变化与北赤道流分叉点南北移动的关系,结果表明:(1)黑潮入侵南海方式多样,既有分支形式,也有弯曲、流套形式。(2)不同年月间,黑潮入侵南海的强弱存在较大差别,120°E断面的次表层盐度极大值的变动可超过0.3。(3)北赤道流分叉点位置的南北变动对黑潮入侵南海的强弱具有重要影响:北赤道流分叉点位置偏北,黑潮入侵南海较强;北赤道流分叉点位置偏南,则黑潮入侵相对较弱。 相似文献
10.
The circulation in the southern Huanghai Sea and northern East China Sea in June 1999 总被引:1,自引:0,他引:1
Yaochu Yuan Yonggang Liu Mingyu Zhou Arata Kaneko Zhou Yuan Noriaki Gohda 《海洋学报(英文版)》2003,22(3):321-332
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 相似文献
11.
北赤道流分叉点及南海北部环流的研究进展 总被引:6,自引:0,他引:6
介绍了北赤道流分叉点、南海北部环流的一些研究成果,并就黑潮对南海的影响所作的研究进行了回顾.北赤道流分叉点的位置对于北赤道流系水体疏运变化及在黑潮和MC之间水体、热量、盐度输运的分配中起着重要的作用.北赤道流分叉点位置约在14.6°N上,分叉点位置随深度增加而北移.分叉点有明显的季节变化和年际变化,在春、夏季向南移动,而在秋、冬季则向北移动.年际变化与ENSO现象相关紧密,在El Nio事件NEC分叉纬度处于最北端,在La Nio事件处于最南端.对于分叉点位置的定量化研究,仍然需要更多的观测结果进行研究.季风和黑潮是影响南海北部环流的两种主要因素.南海北部上层流场主要由广东沿岸流、黑潮入侵流套、东沙海流、南海暖流和吕宋海流组成.除海盆、次海盆尺度环流外,受季风、黑潮和地形等因素的影响,南海表现出多涡结构.通过近些年的卫星观测和数值模拟的结果,人们对南海中尺度涡的认识大大加深,但要想模拟出风应力形成涡的机制,还需要提高风场和模式的分辨率.由于观测资料的限制,对南海流场的垂直结构、以及春-秋季季风转相时期的流场结构等还研究得较少.吕宋海峡水交换是西太平洋对南海影响的主要途径.黑潮在吕宋海峡附近的形变一直是有争议的热点问题,目前对于黑潮入侵有3种观点:(1) 认为黑潮经过吕宋海峡形成流套结构,并分离出中尺度涡影响南海流场、水团结构;(2) 认为黑潮有一直接分支分离出来进入南海形成黑潮分支;(3) 认为吕宋海峡水交换不属于以上两种情况,西太平洋对南海的水团输送另有机制.北赤道流分叉点在对黑潮的水体、热量、盐度输运的分配中起着重要的作用,黑潮对南海北部环流的影响可能与NEC的分叉点位置有关,但目前对NEC的分叉点位置与南海北部环流相关性的研究甚少.最后提出了对未来加强该方面研究的一些展望. 相似文献
12.
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. 相似文献
13.
Surface sediment samples in the near shore area of the north Shandong Peninsula are collected for grain size and element analyses. The results indicate that the surface sediments in the study area are primarily composed of the silt-sized components similar to the Huanghe River. The total concentration of aluminum varies from 5.57% to7.37%(average(6.33 ± 0.40)%), and its spatial distribution is mainly controlled by the grain size. Correlations between the ratio of aluminum to titanium concentration and aluminum concentration, titanium concentration and the mean grain size indicate that aluminum in the near shore surface sediments is affected majorly by the terrigenous source, and partially by the anthropogenic source. The ratios of aluminum to titanium concentrations are larger than the background value of loess matter at some stations due to the existence of excess aluminum associated with human activities. Thus, the sources of aluminum should be identified firstly when aluminum is used as an index of terrigenous matter even in the near shore area dominated by terrigenous deposits. 相似文献
14.
南海环流动力机制研究综述 总被引:31,自引:9,他引:31
南海的环流复杂,但通过近20 a来的研究工作,国内外学者对此已取得了不少的成果.本文就南海环流框架性的问题,综述了有关的文献,认为对南海上层海洋三方面的环流分量的驱动机制已有了初步的认识.这三方面分别是:(1)准季节性风场;(2)黑潮向南海的净输运;(3)黑潮向南海的涡度平流输送.但是对这些驱动的时空变化仍相当不清楚.三者皆增强了南海北部的海盆尺度气旋式环流,其强化的西南向西边界流靠近东沙群岛,建议称为“东沙海流”.没有水文证据显示黑潮水是以分支形式进入南海,其向南海的输运也不可能主要通过中尺度涡过程,具体机制有待研究.每年在南海生成的中尺度涡平均约有10个,风场与沿岸地形所生成的强风应力旋度可能是其主要的驱动机制.作为框架性的认识,也有三方面的工作进行得较少,即:(1)吕宋海峡的上层水交换;(2)南海的中尺度涡生成机制,虽然强风应力旋度及前述的第三种环流驱动机制也有中尺度涡伴生;(3)自吕宋海峡进入的深层水对南海上层海洋环流的影响. 相似文献
15.
利用2011年7月5个断面共30个站位的温盐深(CTD)测量资料,分析东海南部陆架水体的温盐结构和温跃层特征,探讨黑潮和台湾暖流对东海陆架水文状况的影响。结果显示,本区广泛存在着浅部温跃层和深部温跃层。浅部温跃层分布于20 m水深以内,跃层强度普遍较弱,具有明显的日内生消变化。深部温跃层分布于中、外陆架和台湾海峡。在中、外陆架的深水区,跃层底界深度约80 m,跃层厚度约10 m;跃层强度大,约为0.8 ℃/m,且较为稳定。在台湾海峡北部,温跃层分布于水深14~30 m,跃层厚度6~10 m,跃层强度偏弱,为0.2~0.5 ℃/m。在温跃层附近,由于上、下层水团温度、盐度的差异,其混合过程常出现盐指现象。在东海陆架90~110 m等深线之间,深部温跃层之下盘踞着一个深层冷水团,水温为16.8~17.6 ℃。黑潮水的入侵,使得外陆架温跃层强度减弱至0.2~0.5 ℃/m;同时,跃层层位上升,厚度加大。温跃层强度可以作为指示黑潮入侵的灵敏指标。当夏季深部温跃层强度低于0.6 ℃/m,同时伴随跃层厚度加大时,可判别为黑潮入侵。本区夏季黑潮锋可以到达110 m等深线附近。在中陆架50~80 m等深线之间,深部温跃层的消失,说明台湾暖流的强烈影响遍及整个水柱;而从南向北,台湾暖流的影响逐渐减弱。台湾海峡北部深层水温度较低,平均值为22.52 ℃,要比东海南部中陆架深层水低3 ℃,这可能意味着台湾暖流深层水主要源于黑潮分支的加入。 相似文献
16.
利用高分辨率遥感海表温度和海表面风场数据,通过经验正交分解(EOF)和合成分析等方法对春季(3—5月)东海黑潮海温暖舌和海表面风场的年代际变化特征进行分析。结果表明:春季黑潮海温暖舌存在明显的年代际变化特征,在1996/1997年发生由弱到强的位相转换,该年代际变化主要受到北太平洋涡旋振荡(NPGO)的调制。进一步研究表明,与气候态相反,春季黑潮海表温度和风场散度在年代际尺度上表现出显著的负相关关系,合成分析表明,该现象主要是由黑潮西侧东海陆架海域海温的异常增暖所造成。 相似文献
17.
Hiroshi Kuroda Manabu Shimizu Yuuichi Hirota Hideki Akiyama 《Journal of Oceanography》2007,63(5):849-862
Through analysis of monthly in situ hydrographic, tide gauge, altimetry and Kuroshio axis data for the years 1993–2001, the intraannual variability of sea level
around Tosa Bay, Japan, with periods of 2–12 months is examined together with the intraannual variability of the Kuroshio
south of the bay. It is shown that the intraannual variation of steric height on the slope in Tosa Bay can account for that
of sea level at the coast around the bay as well as on this slope. It is found that the steric height (or sea level) variation
on the slope in this bay is mainly controlled by the subsurface thermal variation correlated with the Kuroshio variation off
Cape Ashizuri, the western edge of Tosa Bay. That is, when the nearshore Kuroshio velocity south of the cape is intensified
[weakened] concurrently with the northward [southward] displacement of the current axis, temperature in an entire water column
decreases [increases] simultaneously, mainly due to the upward [downward] displacement of isotherms, coincident with that
of the main thermocline. It follows that the steric height (or sea level) decreases [increases]. 相似文献
18.
渤海、黄海、东海冬季海流场温度场数值模拟和同化技术 总被引:6,自引:0,他引:6
利用NASA高分辨率的卫星遥感资料SST,采用Nudging同化来模拟渤海、黄海、东海的三维温度场,减小用热通量作上边界条件所带来的误差.结果表明,模拟的海流场能较好地反映渤海、黄海、东海的环流特征.数据同化后的温度场优于未经同化的温度场.3个选择站点的同化值与实测值的均方根误差分别为1.307,0.526,0.744,用热通量资料模拟的水温与实测值的均方根误差分别为2.160,0.979,1.330.尽管只同化了海表温度,但数据同化对三维温度场结构都有影响. 相似文献
19.
EcologicalcharacteristicsofOstracodaintheSouthHuanghaiSeaandEastChinaSea¥ChenRuixiangandLinJinghong(ThirdInstituteofOceanogra... 相似文献
20.
Future potential sea level change in the South China Sea(SCS) is estimated by using 24 CMIP5 models under different representative concentration pathway(RCP) scenarios. By the end of the 21 st century(2081–2100 relative to 1986–2005), the multimodel ensemble mean dynamic sea level(DSL) is projected to rise 0.9, 1.6, and 1.1 cm under RCP2.6, RCP4.5, and RCP8.5 scenarios, respectively, resulting in a total sea level rise(SLR) of 40.9, 48.6, and 64.1 cm in the SCS. It indicates that the SCS will experience a substantial SLR over the 21 st century, and the rise is only marginal larger than the global mean SLR. During the same period, the steric sea level(SSL) rise is estimated to be 6.7, 10.0, and 15.3 cm under the three scenarios, respectively, which accounts only for 16%, 21% and 24% of the total SLR in this region. The changes of the SSL in the SCS are almost out of phase with those of the DSL for the three scenarios. The central deep basin has a slightly weak DSL rise, but a strong SSL rise during the 21 st century, compared with the north and southwest shelves. 相似文献