共查询到20条相似文献，搜索用时 171 毫秒
1.
Seok Lee Heung-Jae Lie Cheol-Ho Cho Sok Kuh Kang William J. Teague Kyung-Il Chang Kyu-Min Song Kyung-Hee Oh 《Ocean Science Journal》2011,46(2):73-84
The vertical structure of the M2 tidal current in the Yellow Sea is analyzed from data acquired using an acoustic Doppler current profiler. The observed vertical
profiles of the M2 tidal current are decomposed into two rotating components of counter-clockwise and clockwise, and restructured using a simple
one-point model with a constant vertical eddy viscosity. The analyzed results show that the internal fictional effect dominates
the vertical structure of the tidal current in the bottom boundary layer. In the Yellow Sea, the effect of the bottom friction
reduces the current speed by about 20–40% and induces the bottom phase advance by about 15–50 minutes. In the shallower coastal
regions, the effects of bottom topography are more prominent on the vertical structure of tidal currents. The vertical profile
of the tidal current in summer, when the water column is strongly stratified, is disturbed near the pycnocline layer. The
stratification significantly influences the vertical shear and distinct seasonal variation of the tidal current. 相似文献
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A combination of a three-dimensional hydrodynamic model and in-situ measurements provides the structures of barotropic tides,
tidal circulation and their relationship with turbulent mixing in the Java Sea, which allow us to understand the impact of
the tides on material distribution. The model retains high horizontal and vertical resolutions and is forced by the boundary
conditions taken from a global model. The measurements are composed of the sea level at coastal stations and currents at moorings
embedded in Seawatch buoys, in addition to hydrographic data. The simulated tidal elevations are in good agreement with the
data for the K1 and M2 constituents. The K1 tide clearly shows the lowest mode resonance in the Java Sea with intensification around the nodal point in the central region.
The M2 tide is secondary and propagates westward from the eastern open boundary, along with a counterclockwise amphidromic point
in the western part. The K1 tide produces a major component of tidal energy, which flows westward and dissipates through the node region near the Karimata
Strait. Meanwhile, the M2 tide dissipates in the entire Java Sea. However, the residual currents are mainly induced by the M2 tide, which flows westward following the M2 tidal wave propagation. The tidal mixing is mainly caused by K1 tide which peaks at the central region and is consistent with the uniform temperature and salinity along the vertical dimension.
This mixing is expected to play an important role in the vertical exchange of nutrients and control of biological productivity. 相似文献
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Numerical simulation on diurnal and semidiurnal tidal currents is made for the eastern and southern parts of the East China Sea bounded by the Tsushima, islands of Kyushu and Ryukyu in the east and extending to the central Taiwan Strait in the south. The numerical computation shows that the rapid variation in the seabed topography near the Okinawa Trough may cause computational instability and this instability can be removed by setting a suitable lateral eddy viscosity. The computed results are in good agreement with the observations and indicate that the tidal currents in the greater part of the area studied rotate clockwise. An M2 current-amphidromic point exists in the southern part of the Korea Strait and another one appears in the west of Okinawa with less certainty. K1 and M2 cotidal charts based on the observed and computed tidal currents in the sea and the observed tides on the coast are also given. 相似文献
5.
The characteristics of currents and tidal currents in the Andaman Sea(AS) are studied during the second half of2016 using observed data from a moored acoustic Doppler current profiler(ADCP) deployed at 8.6°N, 95.6°E.During the observation period, the mean flow is 5–10 cm/s and largely southward. The root mean square and kinetic energies of the low and high frequency flows, which are divided by a cutoff period of 5 d, are at the same level, indicating their identical importance to the total current. A power spectrum analysis shows that intraseasonal oscillations, a tidal-related semilunar month signal, a semidiurnal tidal signal and periods of 3–4 d are prominent. The barocliny of an eddy kinetic energy is stronger than the mean kinetic energy, both of which are the strongest on the bottom and the weakest at 70 m depth. Residual currents are largely southward(northward) during the summer(winter) monsoon season. Two striking peaks of the southward flow cause the 80 d period of meridional currents. The first peak is part of a large-scale circulation, which enters the AS through the northern channel and exits through the southern channel, and the second peak is part of a local vortex. The 40 d oscillation of the zonal current is forced by geostrophic variations attributed to local and equatorial remote forcing. The tidal current is dominated by semidiurnal constituents, and among these, M2 and N2 are the top two largest major axes. Moreover, astronomical tidal constituents MM and MSF are also significant. Diurnal constituents are weak and shallow water tides are ignorable. The aims are to introduce the new current data observed in the AS and to provide initial insights for the tidal and residual currents in the Andaman Sea. 相似文献
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南海北部陆架海域内潮特征的观测研究 总被引：1，自引：0，他引：1
利用2014年南海东沙岛西北部海域70余天的流速剖面高频观测资料,研究分析了该海区正压潮、内潮的时空分布特征。结果表明,观测海区正压潮流以O_1,K_1,M_2,S_2为主;斜压潮流中,除四大分潮之外,MU_2与2Q_1分潮能量也较强;内潮的主轴方向基本沿东南-西北方向,近似与局地等深线垂直。全日内潮的锁相部分占全日内潮能量的17.5%,而半日内潮的锁相部分占半日内潮能量的30%;进一步研究发现半日内潮主要由第一模态主导,而全日内潮第二模态占比50%,约为其第一模态能量的两倍;内潮模态能量占比显示出显著的大小潮调制的半月周期。对比不同垂向模态计算方法发现,当流速观测深度有限时,利用全水深温盐资料计算观测范围内流速垂向模态是更为准确的方式。 相似文献
8.
A three-dimensional isopycnic-coordinate internal tidal model is employed to investigate the generation,propagation, vertical structure and energy conversion of M2 internal tides in the Luzon Strait(LS) with mooring observations. Simulated results, especially the tidal current amplitudes, agree well with observations,demonstrating the reasonability and accuracy of the model. Results indicate that M2 internal tides mainly propagate into three directions horizontally, i.e., eastward towards the western Pacific Ocean, westward towards the Dongsha Island and southwestward towards the South China Sea Basin. In the horizontal direction, tidal current amplitudes decrease as distance increases away from the LS; in the vertical direction, they show an obvious decreasing tendency with depth. Between the double ridges of the LS, a clockwise gyre of M2 baroclinic energy flux appears, which is caused by reflections of M2 internal tides at supercritical topographies, and resonance of M2 internal tides happens along 19.5° and 21.5°N due to the heights and separation distance of the double ridges. The total energy conversion in the LS is about 14.20 GW. 相似文献
9.
末次冰消期以来渤、黄、东海陆架潮汐、潮流演变过程模拟研究 总被引：1，自引：0，他引：1
朱玉荣 《中国海洋大学学报(自然科学版)》2002,32(2):279-286
末次盛冰期结束、海侵开始后渤、黄、东海陆架潮汐、潮流的演变对该区泥沙的输运与沉积 ,以及海底地貌的形成、分布以及演变等具有深刻影响。文中数值模拟末次冰消期以来 4个特定时期 ,即比现在海面低 80 m、5 2 m、30 m海面以及全新世最大海侵时渤、黄、东海陆架的潮汐、潮流。根据不同时期的潮汐、潮流分布特征得出 ,末次冰消期以来渤、黄、东海陆架潮汐、潮流的演变过程大致以全新世最大海侵为界划分为两个阶段 :1全新世最大海侵前为渤、黄、东海陆架潮汐、潮流基本分布格局的形成阶段 ;2全新世最大海侵后 ,为基本分布格局的局部调整阶段。末次冰消期以来基本海岸轮廓的变迁是渤、黄、东海陆架区潮汐、潮流演变的主要控制因素 相似文献
10.
南海北部陆架陆坡区海流观测研究 总被引：3，自引：0，他引：3
针对2006-2009年期间,南海北部陆架陆坡区3个站ADCP海流连续观测资料,采用功率谱分析、潮流调和分析方法,重点分析了陆架陆坡区100 m,200 m和1 200 m水深海域海流的垂向结构,探讨了环流的季节变化和空间分布特征,特别讨论了南海暖流和北陆坡流的时空变化特征。结果表明,陆架陆坡区潮流类型属于不规则日潮,深水站点中层表现为正规全日潮类型,垂向为"三层结构",甚至更加复杂。O1,K1,M2,S2等分潮总体上为顺时针旋转,在深水站点,基本表现为西北－东南走向的往复流形态。从能量角度看,表层和底层海流中,潮流所占份额较大,分别占30%~40%和40%~50%,中层较小,约为20%。对东沙群岛西南陆架陆坡区环流,观测计算结果证实了西向强流的存在,且垂向结构具有显著的季节变化,在200 m水深处没有明显的南海暖流,只是10~30 m以上层次存在逆风海流。海南岛以东海域连续15个月表层环流的结果表明,冬季明显受到南海暖流的影响,存在东北向的逆风海流,夏秋季的环流表现为西南向,流速较强,夏季也存在逆风情况,造成上述情形的原因可能是该地南海暖流的流轴具有季节性变化——冬季偏南,夏季偏北。 相似文献
11.
ＭｏｄｅｌｌｉｎｇｏｆｔｈｅｂａｒｏｔｒｏｐｉｃｐｒｏｃｅｓｓｅｓｉｎｔｈｅＢｏｈａｉＳｅａ￥ＨｕａｎｇＤａｊｉ；ＣｈｅｎＺｏｎｇｙｏｎｇａｎｄＳｕＪｉｌａｎ（ＳｅｃｏｎｄＩｎｇｔｉｔｕｔｅｏｆＯｃｅａｎｏｇｒａｐｈｙ，ＳｔａｔｅＯｃｅａｎｉｃＡｄｍ... 相似文献
12.
Tang Yuxiang 《海洋学报(英文版)》1989,8(2):179-190
-A two-dimensional.nonlinear numerical model is used to study the residual current generated by tides in the East China Sea (ECS)and the South Huanghai Sea (SHS). At first, the principal semidiurnal lunar tide (M2)and the tidal current are derived in these areas. The results obtained with the model are strongly supported by the observational results available. Then, the tide-induced residual flow is determined by using the currents generated by the tidal input. The main features of the residual current in ECS and SHS are presented by analyzing the calculated results. Some of the problems are discussed such as the cause of generating residual current and the contribution of the residual current to the observed current. 相似文献
13.
Ｎｕｍｅｒｉｃａｌｓｉｍｕｌａｔｉｏｎｏｆｔｈｒｅｅ－ｄｉｍｅｎｓｉｏｎａｌｔｉｄａｌｃｕｒｒｅｎｔｉｎｔｈｅＢｏｂａｌＳｅａ￥ＤｅｎＺｈｅｎｘｉｎｇ;ＹａｎｇＬｉａｎｗｕ;ａｎｄＪｏｓｅＯｚｅｒ（ＲｅｃｅｉｖｅｄＭａｙ１,１９９３;ａｃｃｅｐｔｅｄ... 相似文献
14.
使用ROMS(regional oceanic modeling system)模式模拟了40年的渤黄东海温盐流，数据包括三维的温度、盐度、流速、流向和海表高度，同时包含了逐小时的潮汐信息。将模拟结果与观测资料和卫星反演数据进行对比，检验了模式准确性。整体上，模式模拟的水位与近岸观测值基本一致，能够准确再现风产生的增水；模式较为准确的再现了渤黄东海的温度分布，在深水区模拟的温盐剖面与观测值基本一致；模式模拟渤黄东海区域的海表高度和海表流与卫星反演结果相比偏小，但分布趋势相近。模式结果可以为研究气候变化对水位的影响和黄海暖舌的扩散过程等现象提供数据支持。 相似文献
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应用MIKE数值模拟软件,采用无结构三角形网格,建立一套计算区域包括整个渤海、黄海、东海以及东海大陆架和琉球群岛的高分辨率数值模型,考虑了实际水深和岸线,外海开边界采用西北太平洋大模型结果的潮位提供,模拟了东中国海潮波的波动过程,对潮波垂直运动过程进行调和分析,得到了渤海、黄海、东海的M2,S2,K1,O1以及N2,K2,P1,Q1八个主要分潮的传播和分布特征。利用中国沿海14个潮位站的调和常数对模型结果进行了验证,验证结果显示模型较为准确可靠。研究结果表明:4个主要半日潮(全日潮)在渤、黄、东海的传播情形基本相似,即潮波在渤海、黄海、东海沿岸的传播性质上类似沿岸开尔文波的传播形态,并且成功再现了计算海域的4个半日分潮无潮点和2个全日分潮无潮点。全日潮振幅各无潮点附近振幅最小,而海湾的波腹区振幅最大,东海潮差呈现近岸方向振幅大、离岸方向振幅小,浙闽沿海振幅也较大,黄海振幅相对较小,渤海振幅在辽东湾和渤海湾顶最大,两个无潮点周边振幅较小。 相似文献
17.
Strong Tidal Mixing and Ventilation of Cold Intermediate Water at Kashevarov Bank, Sea of Okhotsk 总被引：1，自引：0，他引：1
Konstantin A. Rogachev Eddy C. Carmack Alexandr S. Salomatin 《Journal of Oceanography》2000,56(4):439-447
Tidal mixing at the Kashevarov Bank, Sea of Okhotsk, has been investigated using observations of bottom pressure and currents. The tides are dominated by the diurnal constituents. The water motion over the Bank is predominantly controlled by strong diurnal tidal currents, which bring cold water on the bank from its source, a cold intermediate layer. The temperature fluctuations are about 1.2°C at the southern edge of the bank. The maximum observed velocity is about 164 cm/s at the top of the bank. A superposition of the original diurnal constituents K1 and O1 reveals a strong fortnightly (Mf) variability of the current speed. Tidal-induced mixing is responsible for ventilation of the cold intermediate layer of the Sea of Okhotsk. Strong tidal mixing creates a well-defined tidally mixed front around the bank. This front acts like a barrier separating well-mixed water on the bank from stratified water on its flanks. There is a residual current of the order of 10 cm/s. 相似文献
18.
Tang Yuxiang 《海洋学报(英文版)》1990,9(4):487-498
A simple three-dimensional tidal model is used to examine the M2 tidal current distribution in a northeastern part of the East China Sea, especially the vertical variation of the current in the region. Computed M2 current is compared with observations available and found to be in good agreement.Main features of the calculating method in this study are: (1) Vertical variation of the tidal current is taken as a funetion of the depth-mean velocity: (2) the method is applicable to a variety of the vertical eddy viscosities; (3) it has a fine vertical resolution, especially near the sea bootom. So, this method not only enables us to get a steady state solution easily but also depicts effects of the friction on the vertical variation of the current much better. 相似文献
19.
The potential role of the tide-induced time-mean flow (the tidal residual current) in determining transport through the Tsugaru
Strait (located between the East/Japan Sea and the North Pacific) is investigated using a high-resolution numerical barotropic
model. The calculated K1, O1, M2, and S2 tidal fields agree well with available observational records derived from both tide gauge and current meter measurements
in the strait and the adjacent seas. The tidal residual current speed reaches 0.3 ms−1 in two narrow “neck” areas where topographic sills are located. This result suggests that tides should be taken into account
in estimating the long-term water mass and nutrient transport through narrow regions between the East/Japan Sea and the North
Pacific. An interesting aspect of the tidal residual current field is the prediction of several active eddy zones in which
sequences of eddy triplets develop in the vicinity of capes. Our vorticity analysis reveals that the interplay of topographic
effects arising from both the headland and the sill around capes plays a critical role in the formation of these triple eddy
patterns. 相似文献
20.
为验证一个东海潮汐数值模式结果的精度并了解我国东海区域的潮汐特征。该文使用T_TIDE对东海大桥南和洋山站的潮汐资料进行调和分析, 并针对所研究区域最主要的8个分潮: M2、S2、K1、O1、N2、K2、P1、Q1分别对比两站实测数据与模式结果的调和分析结果。结果表明: 两站点的模式结果和观测海表高度的均方误差D与潮汐产生的海表高度变化V的比值为25.99%和25.29%, 模式结果计算所绘制的M2和K1分潮的同潮图与前人研究结果在无潮点的位置、同潮时线、等振幅线的分布和趋势上相似。这说明了使用时间长度相同但年份不同的实测数据验证潮汐数值模式结果的可行性, 并能够帮助了解我国东海区域的潮汐特征。 相似文献