共查询到20条相似文献，搜索用时 15 毫秒
1.
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
2.
Characteristics of water mass under the surface mixed layer in Tsushima Straits and the southwestern Japan Sea in autumn 总被引：1，自引：0，他引：1
Tetsutaro Takikawa Akihiko Morimoto Goh Onitsuka Atsushi Watanabe Masatoshi Moku 《Journal of Oceanography》2008,64(4):585-594
Two different cold waters were found under the surface mixed layer in Tsushima Straits and the southwestern Japan Sea in autumn
2004. One is cold saline water with a low concentration of dissolved oxygen, and the other is cold less saline water with
a high concentration of dissolved oxygen. The older saline water originates from the bottom of the East China Sea, strongly
influenced by the Kuroshio water with high salinity. The bottom density in the eastern channel of the Tsushima Straits is
coincident with that of the East China Sea in autumn, corresponding to the season when the cold saline water was frequently
found in the Tsushima Straits. The newer less saline water originates from the front of Tsushima Warm Current between the
Tsushima Warm Current water and the surface cold water in the Japan Sea. This water is formed by subduction above the isopycnal
surface from the front of the Tsushima Warm Current. 相似文献
3.
K.-I. Chang W.J. Teague S.J. Lyu H.T. Perkins D.-K. Lee D.R. Watts Y.-B. Kim D.A. Mitchell C.M. Lee K. Kim 《Progress in Oceanography》2004,61(2-4):105
A review is made of circulation and currents in the southwestern East/Japan Sea (the Ulleung Basin), and the Korea/Tsushima Strait which is a unique conduit for surface inflow into the Ulleung Basin. The review particularly concentrates on describing some preliminary results from recent extensive measurements made after 1996. Mean flow patterns are different in the upstream and downstream regions of the Korea/Tsushima Strait. A high velocity core occurs in the mid-section in the upstream region, and splits into two cores hugging the coasts of Korea and Japan, the downstream region, after passing around Tsushima Island located in the middle of the strait. Four-year mean transport into the East/Japan Sea through the Korea/Tsushima Strait based on submarine cable data calibrated by direct observations is 2.4 Sv (1 Sv = 106 m3 s−1). A wide range of variability occurs for the subtidal transport variation from subinertial (2–10 days) to interannual scales. While the subinertial variability is shown to arise from the atmospheric pressure disturbances, the longer period variation has been poorly understood.Mean upper circulation of the Ulleung Basin is characterized by the northward flowing East Korean Warm Current along the east coast of Korea and its meander eastward after the separation from the coast, the Offshore Branch along the coast of Japan, and the anticyclonic Ulleung Warm Eddy that forms from a meander of the East Korean Warm Current. Continuous acoustic travel-time measurements between June 1999 and June 2001 suggest five quasi-stable upper circulation patterns that persist for about 3–5 months with transitions between successive patterns occurring in a few months or days. Disappearance of the East Korean Warm Current is triggered by merging the Dok Cold Eddy, originating from the pinching-off of the meander trough, with the coastal cold water carried Southward by the North Korean Cold Current. The Ulleung Warm Eddy persisted for about 20 months in the middle of the Ulleung Basin with changes in its position and spatial scale associated with strengthening and weakening of the transport through the Korea/Tsushima Strait. The variability of upper circulation is partly related to the transport variation through the Korea/Tsushima Strait. Movements of the coastal cold water and the instability of the polar front also appear to be important factors affecting the variability.Deep circulation in the Ulleung Basin is primarily cyclonic and commonly consists of one or more cyclonic cells, and an anticyclonic cell centered near Ulleung Island. The cyclonic circulation is conjectured to be driven by a net inflow through the Ulleung Interplain Gap, which serves as a conduit for the exchange of deep waters between the Japan Basin in the northern East Sea and the Ulleung Basin. Deep currents are characterized by a short correlation scale and the predominance of mesoscale variability with periods of 20–40 days. Seasonality of deep currents is indistinct, and the coupling of upper and deep circulation has not been clarified yet. 相似文献
4.
Variability of Sea Surface Circulation in the Japan Sea 总被引：3，自引：0，他引：3
Composite sea surface dynamic heights (CSSDH) are calculated from both sea surface dynamic heights that are derived from altimetric data of ERS-2 and mean sea surface that is calculated by a numerical model. The CSSDH are consistent with sea surface temperature obtained by satellite and observed water temperature. Assuming the geostrophic balance, sea surface current velocities are calculated. It is found that temporal and spatial variations of sea surface circulation are considerably strong. In order to examine the characteristics of temporal and spatial variation of current pattern, EOF analysis is carried out with use of the CSSDH for 3.5 years. The spatial and temporal variations of mode 1 indicate the strength or weakness of sea surface circulation over the entire Japan Sea associated with seasonal variation of volume transport through the Tsushima Strait. The spatial and temporal variations of mode 2 mostly indicate the temporal variation of the second branch of the Tsushima Warm Current and the East Korean Warm Current. It is suggested that this variation is possibly associated with the seasonal variation of volume transport through the west channel of the Tsushima Strait. Variations of mode 3 indicate the interannual variability in the Yamato Basin. 相似文献
5.
6.
The Current System in the Yellow and East China Seas 总被引：18，自引：1，他引：18
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. 相似文献
7.
Jong-Hwan Yoon 《Journal of Oceanography》1982,38(2):43-51
By using a rectangular basin of uniform depth with inflow and outflow openings, the circulation in the Japan Sea is investigated numerically. Heat flux through the sea surface is determined from the annual mean atmospheric conditions for the Japan Sea, but no wind stress is considered.In the transient state, the warm water supplied through an inflow opening travels cyclonically along the coast as a density-driven boundary current in a rotating system. In the quasi-steady state, the warm water flows northward as a western boundary current which corresponds to the East Korean Warm Current and gradually separates from the coast as it flows northward. No strong boundary current corresponding to the nearshore branch of the Tsushima Current exists.Under annual mean atmospheric conditions, formation of the deep water characteristic of the Japan Sea and of the thermal front corresponding to the Polar Front do not take place. 相似文献
8.
Northern and southern latitudinal transects were conducted west of Tsugaru Strait to estimate the volume transport in this
area. It was found that the Tsushima Warm Current is the northward volume transport across the southern transect and the Northward
Current is the northward volume transport across the northern transect. The current in Tsugaru Strait,viz. the Tsugaru Warm Current, is the flow remaining when the Northward Current is subtracted from the Tsushima Warm Current.
Both CTD transects covered from near-shore to west of the subarctic front, and observed depths were from the surface to the
bottom or to 1000-1500 m depth. Our estimations indicate that large interannual variations of volume transport occur, relative
to the seasonal ones, with interannual variations sometimes exceeding seasonal variations in the Tsushima Warm Current and
the Northward Current. The Tsugaru Warm Current has near-steady transport. Fluctuations in the Tsushima Warm Current are thus
transmitted to the Northward Current. Further, our results revealed seasonal variations in the flow: the baloclinic structure
became deeper in April and the current axis tended to shift in a near-shore direction in October. Therefore, previous studies,
which had shallow reference levels and lacked nearshore stations, may have underestimated the transport and excessive seasonal
variations. 相似文献
9.
By using Acoustic Doppler Current Profiler (ADCP) measurements with the four round-trips method to remove diurnal/semidiurnal
tidal currents, the detailed current structure and volume transport of the Tsushima Warm Current (TWC) along the northwestern
Japanese coast in the northeastern Japan Sea were examined in the period September–October 2000. The volume transport of the
First Branch of the TWC (FBTWC) east of the Noto Peninsula was estimated as approximately 1.0 Sv (106 m3/s), and the FBTWC continued to flow along the Honshu Island to the south of the Oga Peninsula. To the north of the Oga Peninsula,
the Second Branch of Tsushima Warm Current and the eastward current established by the subarctic front were recombined with
the FBTWC and the total volume transport increased to 1.9 Sv. The water properties at each ADCP line strongly suggested that
most of the upper portion of the TWC with high temperature and low salinity flowed out to the North Pacific as the Tsugaru
Warm Current. In the north of the Tsugaru Strait, the volume transport of the northward current was observed to be as almost
1 Sv. However, the component of the TWC water was small (approximately 0.3 Sv). 相似文献
10.
ＤｉｓｔｒｉｂｕｔｉｏｎｏｆｂｉｏｍａｓｓｏｆｚｏｏｐｌａｎｋｔｏｎｉｎｔｈｅＫｕｒｏｓｈｉｏａｒｅａｏｆｔｈｅＥａｓｔＣｈｉｎａＳｅａ￥ＭｅｎｇＦａｎ;ＣｈｅｎＳｈｉｑｕｎａｎｄＷｕＢａｏｌｉｎｇ（ＦｉｒｓｔｉｎｓｔｉｔｕｔｅＯｆＯｃｅａｎｏｇｒａ... 相似文献
11.
Atsuhiko Isobe 《Journal of Oceanography》1999,55(2):185-195
Using a temperature data set from 1961 to 1990, we estimated the monthly distribution of the vertically integrated heat content
in the East China Sea. We then drew the monthly map of the horizontal heat transport, which is obtained as the difference
between the vertically integrated heat content and the surface heat flux. We anticipate that its distribution pattern is determined
mainly due to the advection by the ocean current if it exists stably in the East China Sea. The monthly map of the horizontal
heat transport showed the existence of the Taiwan-Tsushima Warm Current System (TTWCS) at least from April to August. The
T-S (temperature-salinity) analysis along the path of TTWCS indicated that the TTWCS changes its T-S property as it flows
in the East China Sea forming the Tsushima Warm Current water. The end members of the Tsushima Warm Current water detected
in this study are water masses in the Taiwan Strait and the Kuroshio surface layer, the fresh water from the mainland of China,
and the southern tip of the Yellow Sea Cold Water extending in the northern part of the East China Sea.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
12.
A significant surface net heat loss appears around the Kuroshio and the Tsushima Warm Current regions. The area where the
surface heat loss occurs should require heat to be supplied by the current to maintain the long-term annual heat balance.
Oceanic heat advection in these regions plays an important role in the heat budget. The spatial distribution of the heat supply
by the Tsushima Warm Current near the surface was examined by calculating the horizontal heat supply in the surface layer
of the East Sea (the Japan Sea) (ESJS), directly from historical sea surface temperature and current data. We have also found
a simple estimation of the effective vertical scale of heat supply by the current to compensate net heat loss using the heat
supplied by the current in the surface 10 m layer. The heat supplied by the current for the annual heat balance was large
in the Korea/Tsushima Strait and along the Japanese Coast, and was small in the northwestern part of the ESJS. The amount
of heat supplied by the current was large in the northwestern part and small in the south-eastern part of the ESJS. These
features suggest that the heat supplied by the Tsushima Warm Current is restricted to near the surface around the northeastern
part and extends to a deeper layer around the southeastern part of the ESJS.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
13.
The Korea (Tsushima) Strait is an important seaway through which the warm Tsushima Current flows into the East Sea (Japan
Sea). A paleogeographic map constrained by a regional sea-level curve developed on the basis of a number of recent 14C radiocarbon dates suggests that the Korea Strait was not closed during the last glacial period. Rather, it was open as a
channel-like seaway linking the western North Pacific and the East Sea. Some fraction of the paleo-Tsushima Current inflow
presumably continued at that time through the Korea Strait. The activity of the paleo-Tsushima Current is evidenced by the
distribution pattern of river-derived lowstand deposits, consisting of a beach/shoreface complex and lowstand deltaic wedges.
Received: 16 April 1999 / Revision accepted: 25 February 2000 相似文献
14.
A Numerical Modeling of the Upper and the Intermediate Layer Circulation in the East Sea 总被引：1，自引：0，他引：1
Circulation in the upper and the intermediate layer of the East Sea is investigated by using a fine resolution, ocean general
circulation model. Proper separation of the East Korean Warm Current from the coast is achieved by adopting the isopycnal
mixing, and using the observed heat flux (Hirose et al., 1996) and the realistic wind stress (Na et al., 1992). The simulated surface circulation exhibits a remarkable seasonal variation in the flow patterns of the Nearshore
Branch, the East Korean Warm Current and the Cold Currents. East of the Oki Bank, the Nearshore Branch follows the isobath
of shelf topography from late winter to spring, while in summer and autumn it meanders offshore. The Nearshore Branch is accompanied
by cyclonic and anticyclonic eddies in a fully developed meandering phase. The meandering and the eddy formation of the Nearshore
Branch control the interior circulation in the Tsushima Current area. A recirculation gyre is developed in the region of the
East Korean Warm Current in spring and grown up to an Ulleung Basin scale in summer. A subsurface water is mixed with the
fresh surface water by winter convection in the northeastern coastal region of Korea. The well-mixed low salinity water is
transported to the south by the Cold Currents, forming the salinity minimum layer (Intermediate Water) beneath the East Korean
Warm Current water. The recirculation gyre redistributes the core water of the salinity minimum layer in the Ulleung Basin.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
15.
本文全面地分析了此段海流的流路与流速结构，首次提出研究海域近底层的环流示意图。指出在夏季，韩国南岸和日本九州北岸均存在着一支南下的逆流，九州西岸出现两种或多种形式的流路。对马暖流在源地流速很弱，流向不稳定，流路时隐时显不明显，只有离开源地后才逐渐显示出一支海流轮廓；强流区在朝鲜海峡附近。该海流可明显地划分为三段。流速夏强冬弱，夏季流幅宽约８０ｋｍ。 相似文献
16.
基于ROMS(Regional Ocean Modeling System)模式,对西北太平洋海域进行了水平分辨率高达4km的水动力环境数值模拟,该分辨率可以很好地分辨我国东海陆架环流以及中尺度涡旋等过程,此外模式考虑了8个分潮,模式结果很好地再现了黄、东海陆架环流等。基于模式结果,对"桑吉"号泄漏物质可能的扩散和迁移轨迹进行了数值模拟分析。在"桑吉"号沉船位置的表、底Ekman层内,释放拉格朗日粒子和示踪物来示踪"桑吉"号泄漏物质的可能影响范围。拉格朗日粒子和示踪物模拟结果表明:在未来3个月,"桑吉"号泄漏物质对我国黄海的影响较小,其主要随着对马暖流进入日本海和随着黑潮进入日本九州以南的太平洋海域。随着冬、春的季节转换,三个月后,北风会减弱,减弱风场的试验表明,风场减弱会减少泄漏物质向黄海的输送。5月份后黄海冷水团逐渐形成,由于斜压效应,在黄海深层水中会逐渐建立起气旋式环流,从而进一步阻碍了"桑吉"号泄漏物质向黄海的输送,该气旋式环流有利于"桑吉"号泄漏物质通过对马海峡向日本海的输送,而会抑制底层泄漏物质向我国黄海西侧的输送。 相似文献
17.
Hydrographic conditions in the Tsushima Strait revisited 总被引：1，自引：1，他引：0
Long-term averaged temperature and salinity distributions in the Tsushima Strait are investigated on the basis of a concurrent
dataset of the eastern and western channels during 1971–2000. Both temperature and salinity show a clear seasonal variation
with weak and strong stratifications in December–April and June–October, respectively. The largest standard deviations occur
in summer around the thermocline for temperature and in the surface layer for salinity. This indicates large interannual variability
in the development of a thermocline and low salinity water advection from the East China Sea. The water masses in both channels
are distinctly different from each other; the water in the western channel is generally colder and fresher than that in the
eastern channel throughout the year. Baroclinic transport based on the density distributions shows a seasonal variation with
a single peak in August for the eastern channel and double peaks in April and August for the western channel. However, this
cannot explain the seasonal variation in the total volume transport estimated from the sea level differences across the channels.
The spatial distribution of baroclinic transport shows a year-round negative transport towards the East China Sea behind the
Iki Island in the eastern part of the eastern channel. This negative transport reflects the baroclinic structure between the
offshore Tsushima Current Water and cold coastal water. The corresponding southwestward currents are found in both Acoustic
Doppler Current Profiler (ADCP) and high frequency (HF) radars observations. 相似文献
18.
Thermal fronts and cross-frontal heat flux in the southern Huanghai Sea and the East China Sea 总被引：1，自引：0，他引：1
Synoptic features in/around thermal fronts and cross-frontal heat fluxes in the southern Huanghai./Yellow Sea and East China Sea （HES） were examined using the data collected from four airborne expendable bathythermograph surveys with horizontal approxmately 35 km and vertical 1 m（from the surface to 400 m deep） spacings. Since the fronts are strongly affected by HES current system, the synoptic thermal features in/around them represent the interaction of currents with surrounding water masses. These features can not be obtained from climatological data. The identified thermal features are listed as follows ： （ 1 ） multiple boundaries of cold water, asymmetric thermocline intrusion, locally-split front by homogeneous water of approxmately 18 ℃, and mergence of the front by the Taiwan Warm Current in/around summertime southern Cheju - Changjiang/Yangtze front and Tsushima front; （2） springtime frontal eddy-like feature around Tsushima front; （3） year-round cyclonic meandering and summertime temperature-inversion at the bottom of the surface mixed layer in Cheju - Tsushima front; and （4） multistructure of Kuroshio front. In the Kuroshio front the mean variance of vertical temperature gradient is an order of degree smaller than that in other HES fronts. The southern Cheju- Changjiang front and Cheju -Tsushima front are connected with each other in the summer with comparable cross-frontal temperature gradient. However, cross-frontal heat flux and lateral eddy diffusivity are stronger in the southern Cheju - Changjiang front. The cross-frontal heat exchange is the largest in the mixing zone between the modified Huanghai Sea bottom cold water and the Tsushima Warm Current, which is attributable to enhanced thermocline intrusions. 相似文献
19.
A Box Model of Glacial-Interglacial Variability in the Japan Sea 总被引：2，自引：0，他引：2
The Japan Sea has experienced drastic changes in the last 60 ka: the surface water was colder than the present value by five degrees and extremely freshened (24 ppt) in the last glacial maximum (15 ka), and then it contained Oyashio water for a few thousand years. It is an open question whether the inflow-outflow pattern was entirely reversed, opposite to the present exchange with an inflow through Tsushima Strait and an outflow through Tsugaru Strait. A box model is employed with two boxes representing the northern and the southern half domains in the upper (300-m-thick) layer. The model is driven by atmospheric forcing and inflow through Tsushima Strait and/or Tsugaru Strait. Here, the net transport through Tsushima to Tsugaru is given in the model. A baroclinic component is added to the net transport through each strait. It is the baroclinic components that allow the upper and the lower portions to flow to the opposite directions in the straits, and hence a reversal flow becomes possible against the net transport, under the condition of an extremely freshened Japan Sea. The fresh surface layer in 1814 ka is attributable to a near-shutoff of the inflow due to the low sea level. Shortly after the near-shutoff, the baroclinic transport through Tsugaru Strait yields intrusion of the Oyashio water into the Japan Sea. Thus, it is implied that Oyashio water existed in the Japan Sea a few thousand years after the reopening of Tsugaru Strait, even though the net transport was one-way, similar to the present state. 相似文献
20.
Modeling of the wind-driven circulation in the Japan Sea using a reduced gravity model 总被引：1，自引：0，他引：1
The surface circulation in the Japan Sea is investigated using a 1.5 layer reduced gravity model. Historical observations suggest strongly that an anti-clockwise circulation is dominant in the subpolar region north of the Polar Front as a general feature. This anti-clockwise circulation as well as the branching of the Tsushima Warm Current was simulated well by incorporating the Naet al. (1992)'s wind stress. The positive curl of the wind stress in the northern and the northwestern Japan Sea was found to play an important role in the formation of the subpolar gyre and the separation of the western boundary current (the East Korean Warm Current) in the Japan Sea. 相似文献