共查询到20条相似文献，搜索用时 15 毫秒
1.
Brian K. Arbic Stephen T. Garner Robert W. Hallberg Harper L. Simmons 《Deep Sea Research Part II: Topical Studies in Oceanography》2004,51(25-26):3069
This paper examines the accuracy of surface elevations in a forward global numerical model of 10 tidal constituents. Both one-layer and two-layer simulations are performed. As far as the authors are aware, the two-layer simulations and the simulations in a companion paper (Deep-Sea Research II, 51 (2004) 3043) represent the first published global numerical solutions for baroclinic tides. Self-consistent forward solutions for the global tide are achieved with a convergent iteration procedure for the self-attraction and loading term. Energies are too large, and elevation accuracies are poor, unless substantial abyssal drag is present. Reasonably accurate tidal elevations can be obtained with a spatially uniform bulk drag cd or horizontal viscosity KH, but only if these are inordinately large. More plausible schemes concentrate drag over rough topography. The topographic drag scheme used here is based on an exact analytical solution for arbitrary small-amplitude terrain, and supplemented by dimensional analysis to account for drag due to flow-splitting and low-level turbulence as well as that due to breaking of radiating waves. The scheme is augmented by a multiplicative factor tuned to minimize elevation discrepancies with respect to the TOPEX/POSEIDON (T/P)-constrained GOT99.2 model. The multiplicative factor may account for undersampled small spatial scales in bathymetric datasets. An optimally tuned multi-constituent one-layer simulation has an RMS elevation discrepancy of 9.54 cm with respect to GOT99.2, in waters deeper than 1000 m and over latitudes covered by T/P (66N to 66S). The surface elevation discrepancy decreases to 8.90 cm (92 percent of the height variance captured) in the optimally tuned two-layer solution. The improvement in accuracy is not due to the direct surface elevation signature of internal tides, which is of small amplitude, but to a shift in the barotropic tide induced by baroclinicity. Elevations are also more accurate in the two-layer model when pelagic tide gauges are used as the benchmark, and when the T/P-constrained TPXO6.2 model is used as a benchmark in deep waters south of 66S. For Antarctic diurnal tides, the improvement in forward model elevation accuracy with baroclinicity is substantial. The optimal multiplicative factor in the two-layer case is nearly the same as in the one-layer case, against initial expectations that the explicit resolution of low-mode conversion would allow less parameterized drag. In the optimally tuned two-layer M2 solution, local values of the ratio of temporally averaged squared upper layer speed to squared lower layer speed often exceed 10. 相似文献
2.
Kaushik Sasmal Eiji Masunaga Adrean Webb Oliver B. Fringer Edward S. Gross Matthew D. Rayson Hidekatsu Yamazaki 《Journal of Oceanography》2018,74(2):169-186
The three-dimensional numerical model SUNTANS is applied to investigate river plume mixing in Otsuchi Bay, an estuary located along the Sanriku Coast of Iwate, Japan. Results from numerical simulations with different idealized forcing scenarios (barotropic tide, baroclinic tide, and diurnal wind) are compared with field observations to diagnose dominant mixing mechanisms. Under the influence of combined barotropic, baroclinic and wind forcing, the model reproduces observed salinity profiles well and achieves a skill score of 0.94. In addition, the model forced by baroclinic internal tides reproduces observed cold-water intrusions in the bay, and barotropic tidal forcing reproduces observed salt wedge dynamics near the river mouths. Near these river mouths, vertically sheared flows are generated due to the interaction of river discharge and tidal elevations. River plume mixing is quantified using vertical salt flux and reveals that mixing near the vicinity of the river mouth, is primarily generated by the barotropic tidal forcing. A 10 ms?1 strong diurnal breeze compared to a 5 ms?1 weak breeze generates higher mixing in the bay. In contrast to the barotropic forcing, internal tidal (baroclinic) effects are the dominant mixing mechanisms away from the river mouths, particularly in the middle of the bay, where a narrow channel strengthens the flow speed. The mixing structure is horizontally asymmetric, with the middle and northern parts exhibiting stronger mixing than the southern part of the bay. This study identifies several mixing hot-spots within the bay and is of great importance for the coastal aquaculture system. 相似文献
3.
吐噶喇海峡是西北太平洋重要的内潮产生区域,该区域内产生的内潮对于东海陆架和西北太平洋的混合和物质输运有十分重要的作用。水平分辨率为3km的JCOPE-T(JapanCoastalOcean PredictabilityExperiment—Tides)水动力学模式的结果表明,吐噶喇海峡的内潮主要产生在地形变化剧烈的海山和海岛附近,其引起的等密面起伏振幅可达30m。吐噶喇海峡的内潮在垂直于等深线方向分为两支向外传播:一支向西北方向传播,进入东海陆架后迅速减小;另一支向东南方向传播,进入西北太平洋。吐噶喇海峡潮能丰富,其在约半个月内的平均输入的净正压潮能通量为13.92GW,其中约有3.73GW转化为内潮能量。生成的内潮能量有77.2%在当地耗散,传出的内潮能通量为0.84GW,主要通过西北和东南两个边界传出。该区域潮能通量有显著的大小潮变化,大潮期间输入的正压潮净能通量和产生的内潮能通量均约为小潮期间的2倍,但其主要产生区域基本不变,且内潮能量耗散比率均在产生的内潮通量的76%—79%。另外,内潮能通量的传播方向也没有发生变化,仍主要通过西北和东南两个边界传出。因此,大小潮的变化仅影响吐噶喇海峡处产生的内潮能量的大小,不影响其产生区域、传播方向和耗散比率。 相似文献
4.
5.
Numerical study of baroclinic tides in Luzon Strait 总被引：6，自引：1，他引：5
The spatial and temporal variations of baroclinic tides in the Luzon Strait (LS) are investigated using a three-dimensional
tide model driven by four principal constituents, O1, K1, M2 and S2, individually or together with seasonal mean summer or winter stratifications as the initial field. Barotropic tides propagate
predominantly westward from the Pacific Ocean, impinge on two prominent north-south running submarine ridges in LS, and generate
strong baroclinic tides propagating into both the South China Sea (SCS) and the Pacific Ocean. Strong baroclinic tides, ∼19
GW for diurnal tides and ∼11 GW for semidiurnal tides, are excited on both the east ridge (70%) and the west ridge (30%).
The barotropic to baroclinic energy conversion rate reaches 30% for diurnal tides and ∼20% for semidiurnal tides. Diurnal
(O1 and K1) and semidiurnal (M2) baroclinic tides have a comparable depth-integrated energy flux 10–20 kW m−1 emanating from the LS into the SCS and the Pacific basin. The spring-neap averaged, meridionally integrated baroclinic tidal
energy flux is ∼7 GW into the SCS and ∼6 GW into the Pacific Ocean, representing one of the strongest baroclinic tidal energy
flux regimes in the World Ocean. About 18 GW of baroclinic tidal energy, ∼50% of that generated in the LS, is lost locally,
which is more than five times that estimated in the vicinity of the Hawaiian ridge. The strong westward-propagating semidiurnal
baroclinic tidal energy flux is likely the energy source for the large-amplitude nonlinear internal waves found in the SCS.
The baroclinic tidal energy generation, energy fluxes, and energy dissipation rates in the spring tide are about five times
those in the neap tide; while there is no significant seasonal variation of energetics, but the propagation speed of baroclinic
tide is about 10% faster in summer than in winter. Within the LS, the average turbulence kinetic energy dissipation rate is
O(10−7) W kg− 1 and the turbulence diffusivity is O(10−3) m2s−1, a factor of 100 greater than those in the typical open ocean. This strong turbulence mixing induced by the baroclinic tidal
energy dissipation exists in the main path of the Kuroshio and is important in mixing the Pacific Ocean, Kuroshio, and the
SCS waters. 相似文献
6.
《Ocean Modelling》2002,4(3-4):221-248
Three-dimensional numerical simulations of the generation and propagation of the semidiurnal internal tide in a submarine canyon with dimensions similar to those of the Monterey Canyon are carried out using a primitive equation model. Forcing with just sea level at the offshore boundary in an initially horizontally homogeneous ocean with realistic vertical stratification, internal tides are generated at the canyon foot and rim, and along portions of the canyon floor. The results compare favorably with observations, both indicating enhancement of energy along the canyon floor propagating at an angle consistent with linear internal wave theory. Due to the earth's rotation, internal tide energy is distributed asymmetrically in the cross-canyon direction, favoring the southern side. The effect of canyon floor slope is explored, with the finding that small changes in the slope result in large changes in the amount and distribution of the internal tide energy. Canyons whose floors are subcritical with respect to the semidiurnal frequency along their entire length have very little baroclinic energy, whereas canyons that are near-critical along much of their length, such as the Monterey Canyon, develop strong internal tides that propagate shoreward. Canyons that are near-critical at their mouths but supercritical further inshore generate the most internal tidal energy overall, although little of it makes it onto the continental shelf shoreward of the canyon head. The effects of internal tides within the canyons can be seen outside the canyons as well. Water is transported from depth onto the adjacent continental shelf along the canyon rims. This tidal pumping can be responsible for alongshore internal tide propagation and tidal-period surface currents with relatively small horizontal scales of variability. 相似文献
7.
Walter Munk 《Progress in Oceanography》1997,40(1-4)
Topex/Poseidon (T/P) altimetry has reopened the problem of how tidal dissipation is to be allocated. There is now general agreement of a M2 dissipation by 2.5 Terawatts (1 TW = 1012 W), based on four quite separate astronomic observational programs. Allowing for the bodily tide dissipation of 0.1 TW leaves 2.4 TW for ocean dissipation. The traditional disposal sites since
(1920) have been in the turbulent bottom boundary layer (BBL) of marginal seas, and the modern estimate of about 2.1 TW is in this tradition (but the distribution among the shallow seas has changed radically from time to time). Independent estimates of energy flux into the marginal seas are not in good agreement with the BBL estimates.T/P altimetry has contributed to the tidal problem in two important ways. The assimilation of global altimetry into Laplace tidal solutions has led to accurate representations of the global tides, as evidenced by the very close agreement between the astronomic measurements and the computed 2.4 TW working of the Moon on the global ocean. Second, the detection by
and
(1996) of small surface manifestation of internal tides radiating away from the Hawaiian chain has led to global estimates of 0.2 to 0.4 TW of conversion of surface tides to internal tides. Measurements of ocean microstructure yields 0.2 TW of global dissipation by pelagic turbulence (away from topography). We propose that pelagic turbulence is maintained by topographic scattering of barotropic into baroclinic tidal energy, via internal tides and internal waves. Previous estimates by
(1974);
, (1982)) of this conversion along 150,000 km of continental coastlines gave a negligible 0.02 TW; evidently the important conversion takes place along mid-ocean ridges.The maintenance of the abyssal global stratification requires a much larger expenditure of power. 2 TW versus 0.2 TW. This is usually attributed to wind forcing. If tidal power is to play a significant role here, then the BBL estimates need to be reduced. The challenge is to estimate dissipation from the energy flux divergence in the T/P adjusted tidal models, without prior assumptions concerning the dissipation processes. 相似文献
8.
基于ROMS(Regional Ocean Modeling System)模式,设计了9组理想数值实验,研究了内潮的产生对地形和背景层结环境的敏感性。结果表明:高斯海脊两侧地形梯度较大的超临界坡面处是内潮的主要源区;地形和层结环境的变化对内潮生成有很大影响;如地形和层结保持不变,不同的网格水平分辨率和垂向层数条件下估算的内潮转换率存在差别;地形和跃层的相对空间关系对内潮生成及其引起的水体混合强度存在影响。高分辨率的地形和合适的背景层结是内潮模拟的关键。该结论对于内潮形成的数值模拟研究有一定参考价值。 相似文献
9.
B. A. Kagan A. A. Timofeev E. V. Sofina 《Izvestiya Atmospheric and Oceanic Physics》2010,46(5):652-662
The modeling results of surface and internal M2 tides for summer and winter periods in the Arctic Ocean (AO) are presented. We employed a modified version of the three-dimensional
finite-element hydrothermodynamic model QUODDY-4 differing from the original model by using a rotated (instead of spherical)
coordinate system and by considering the equilibrium-tide effects. It has been shown that the modeling results for the surface
tide differs little from the results obtained earlier by other authors. According to these results, the amplitudes of internal
tidal waves (ITWs) in the AO are significantly lower than in other oceans and the ITWs proper have the character of trapped
waves. Their source of generation is located at the continental slope northwest of the New Siberian Islands. Our results are
consistent with the fields of average (over a tidal cycle) and integral (by depth) densities of baroclinic tidal energy, the
maximum baroclinic tidal velocity, and the coefficient of diapycnic mixing. The local rate of baroclinic tidal energy dissipation
at the AO ridges increases as it approaches the bottom, as was observed on Mid-Atlantic and Hawaii ridges (but merely within
the bottom boundary layer) and is two to three orders of magnitude lower than in other oceans. The ITW degeneration scale
in the AO is several hundreds of kilometers in summer and winter, remaining within the range of its values between 100 and
1000 km in mid- and low-latitude oceans. In both seasons, the integral (over the AO area) rate of baroclinic tidal energy
dissipation is two orders of magnitude lower than the global estimate (2.5 × 1012 W). 相似文献
10.
The performance of a z-level ocean model, the Modular Ocean Model Version 4(MOM4), is evaluated in terms of simulating the global tide with different horizontal resolutions commonly used by climate models. The performance using various sets of model topography is evaluated. The results show that the optimum filter radius can improve the simulated co-tidal phase and that better topography quality can lead to smaller rootmean square(RMS) error in simulated tides. Sensitivity experiments are conducted to test the impact of spatial resolutions. It is shown that the model results are sensitive to horizontal resolutions. The calculated absolute mean errors of the co-tidal phase show that simulations with horizontal resolutions of 0.5° and 0.25° have about 35.5% higher performance compared that with 1° model resolution. An internal tide drag parameterization is adopted to reduce large system errors in the tidal amplitude. The RMS error of the best tuned 0.25° model compared with the satellite-altimetry-constrained model TPXO7.2 is 8.5 cm for M_2. The tidal energy fluxes of M_2 and K_1 are calculated and their patterns are in good agreement with those from the TPXO7.2. The correlation coefficients of the tidal energy fluxes can be used as an important index to evaluate a model skill. 相似文献
11.
Hui Qian Ping-Tung Shaw Dong Shan Ko 《Deep Sea Research Part I: Oceanographic Research Papers》2010,57(12):1521-1531
A three-dimensional nonhydrostatic numerical model is used to study the generation of internal waves by the barotropic tidal flow over a steep two-dimensional ridge in an ocean with strong upper-ocean stratification. The process is examined by varying topographic width, amplitude of the barotropic tide, and stratification at three ridge heights. The results show that a large amount of energy is converted from the barotropic tide to the baroclinic wave when the slope parameter, defined as the ratio of the maximum ridge slope to the maximum wave slope, is greater than 1. The energy flux of internal waves can be normalized by the vertical integral of the buoyancy frequency over the ridge depths and the kinetic energy of the barotropic tides in the water column. A relationship between the normalized energy flux and the slope parameter is derived. The normalized energy flux reaches a constant value independent of the slope parameter when the slope parameter is greater than 1.5. It is inferred that internal wave generation is most efficient at the presence of strong upper-ocean stratification over a steep, tall ridge. In the Luzon Strait, the strength of the shallow thermocline and the location of the Kuroshio front could affect generation of internal solitary waves in the northern South China Sea. 相似文献
12.
Ned P. Smith 《Estuarine, Coastal and Shelf Science》1985,21(5):623-632
Current measurements during a 32-day study period in late spring, 1977, are used to quantify the magnitude and relative importance of tidal and wind-driven motion in the interior of the Indian River lagoon, on the Atlantic coast of Florida. Harmonic analysis of the total longitudinal flow along the axis of the lagoon isolates the tidal component of the current; non-tidal flow is revealed by subtracting the tidal current from the total current, and making corrections for non-linear relationships between the current and both surface wind stress and bottom friction. A one-layer, one-dimensional model is developed to simulate wind drift. A quadratic bottom friction term with a drag coefficient of 15 × 10?3 gives results which compare most favourably with observations. Results indicate that tidal forcing explains approximately 45% of the total variance at the study site, 25 km from the nearest inlet. Local wind forcing accounts for 44% of the non-tidal flow. The remainder of the variance is attributed to freshwater outflow through the lagoon and non-local forcing. 相似文献
13.
《Deep Sea Research Part I: Oceanographic Research Papers》2001,48(6):1375-1399
Semidiurnal tides, and especially the lunar tide M2, are dominant dynamics in the Bay of Biscay. Strong tidal currents are associated with the presence of a significant continental slope. By combining Newton's gravitation laws and Euler's equations, Laplace's equations contain the astronomical forcing responsible for the observed semidiurnal tides. In shallow waters, this direct forcing is often neglected. We study here its influence on the tidal dynamics over the continental slope through the development of a simple model describing the barotropic semidiurnal dynamics on a transect perpendicular to the slope. This new model results from the combination of two different models, i.e. the one developed by Rosenfeld and Beardsley (1987), which takes into account the tide-generating force, and that of Battisti and Clarke (1982), which neglects it. A first model is developed by neglecting the direct astronomical forcing in equations: it consists in solving a second-order homogeneous propagation equation for the barotropic semidiurnal tide and needs only coastal conditions as well as the knowledge of the along-slope wave number of the solution. For a mean slope typical of the South Brittany area, this non-forced model provides results in accordance with those of Battisti and Clarke and Le Cann (1990): in particular, in the upper part of the slope, it shows a polarization inversion of tidal ellipses characteristic of the tidal dynamics observed in this area. Then, the direct astronomical forcing is kept in equations. The simple model developed without this forcing is fitted in order to solve the resulting forced propagation equation for the barotropic tide. The solution of this second model is the sum of a forced wave responding to the direct astronomical forcing and of a free wave generated at the coastal boundary. Under the same boundary conditions, the results obtained with the influence of the tide-generating force are then compared with those obtained without it. This comparison allows one to apprehend the importance of the direct astronomical forcing on tidal dynamics across the slope: in particular, the main difference appears in deep waters where this forcing induces a phase-lag between the plain and the shelf for the sea-surface slope. 相似文献
14.
Surface manifestation of internal tides in the deep ocean: observations from altimetry and island gauges 总被引：3，自引：0，他引：3
The sea-surface height signatures of internal tides in the deep ocean, amounting to a few centimeters or less, are studied using two complementary measurement types: satellite altimetry and island tide gauges. Altimetry can detect internal tides that maintain coherence with the astronomical forcing; island gauges can monitor temporal variability which, in some circumstances, is due to internal tides varying in response to changes in the oceanic medium. This latter mechanism is at work at Hilo and other stations on the northern coasts of the Hawaiian Islands. By detecting spatially coherent low-frequency internal-tide modulations, the tide gauges, along with inverted echo sounders at sea, suggest that the mean internal tide is also spatially coherent; satellite altimetry confirms this. At Hawaii and in many other places, Topex/Poseidon altimetry detects mean surface waves, spatially coherent and propagating great distances (> 1000 km) before decaying below background noise. When temporal variability is small, the altimetry (plus information on ocean density) sets useful constraints on energy fluxes into internal tides. At the Hawaiian Ridge, 15 GW of tidal power is being converted from barotropic to first-mode baroclinic motion. Examples elsewhere warn that a simplistic interpretation of the altimetry, without regard to variability, noise, or in situ information, may be highly misleading. With such uncertainties, extension of the Hawaiian results into a usefully realistic estimate of the global internal-tide energy balance appears premature at this time. 相似文献
15.
《Ocean Modelling》2011,36(4):304-313
We implemented an explicit forcing of the complete lunisolar tides into an ocean model which is part of a coupled atmosphere–hydrology–ocean–sea ice model. An ensemble of experiments with this climate model shows that the model is significantly affected by the induced tidal mixing and nonlinear interactions of tides with low frequency motion. The largest changes occur in the North Atlantic where the ocean current system gets changed on large scales. In particular, the pathway of the North Atlantic Current is modified resulting in improved sea surface temperature fields compared to the non-tidal run. These modifications are accompanied by a more realistic simulation of the convection in the Labrador Sea. The modification of sea surface temperature in the North Atlantic region leads to heat flux changes of up to 50 W/m2. The climate simulations indicate that an improvement of the North Atlantic Current has implications for the simulation of the Western European Climate, with amplified temperature trends between 1950 and 2000, which are closer to the observed trends. 相似文献
16.
Ocean surface waves are strongly forced by high wind conditions associated with winter storms in the Sea of Japan. They are also modulated by tides and storm surges. The effects of the variability in surface wind forcing, tides and storm surges on the waves are investigated using a wave model, a high-resolution atmospheric mesoscale model and a hydrodynamic ocean circulation model. Five month-long wave model simulations are inducted to examine the sensitivity of ocean waves to various wind forcing fields, tides and storm surges during January 1997. Compared with observed mean wave parameters, results indicate that the high frequency variability in the surface wind filed has very great effect on wave simulation. Tides and storm surges have a significant impact on the waves in nearshores of the Tsushima-kaihyō, but not for other regions in the Sea of Japan. High spatial and temporal resolution and good quality surface wind products will be crucial for the prediction of surface waves in the JES and other marginal seas, especially near the coastal regions. 相似文献
17.
黄海在有无潮作用下对“布拉万”不同响应的数值模拟研究 总被引：2，自引：0，他引：2
黄海是典型的强潮驱动的陆架浅海。为了研究黄海对台风的响应特点,本文利用区域海洋模式(Regional Ocean Modeling Systems,ROMS)分别模拟了在有潮和无潮作用下黄海对台风"布拉万"的响应过程。结果表明,不管潮存在与否,"布拉万"经过黄海后都引起了海表面降温和流速的近惯性振荡响应,这种响应主要分布于黄海中部较深区域,带通滤波提取的近惯性流速具有垂向第一模态特征。同时,研究发现强背景潮流能显著地影响黄海对"布拉万"的响应过程。主要结论如下:一方面,由于潮的存在,近岸垂向混合均匀的较暖水体与远岸较冷水体之间会形成潮混合温度锋面,"布拉万"过后,暖水发生了明显的离岸扩张,尽管路径右侧的混合层降温更显著,但是左侧即黄海西岸的暖水扩张更明显;另一方面,潮的存在减弱了布拉万产生的近惯性振荡响应,半日潮流在黄海仍然占据主导地位。在混合层中潮流的作用减弱了"布拉万"产生的近惯性能量,但也使其更易穿过跃层传入黄海内部。 相似文献
18.
Significant fluctuations of the currents of the tidal frequencies have been detected in the Kuroshio Current northeast of Taiwan and in the Tokara Strait, with total amplitudes comparable to the mean surface current (about 4050 cm s−1). At the continental shelf the tidal signal varies considerably with distance from the axis of the Kuroshio. Tidal ellipses on the continental shelf consistently have major axes in the northwest-southeast direction. Because tidal signals in the Kuroshio regions have very small spatial scales, they may not be caused by the barotropic tide but the baroclinic tide. It is inferred that the Kuroshio interacts with the baroclinic tides over the continental slope. 相似文献
19.
Estimation of baroclinic tide energy available for deep ocean mixing based on three-dimensional global numerical simulations 总被引：1，自引：0，他引：1
The global distributions of the major semidiurnal (M2 and S2) and diurnal (K1 and O1) baroclinic tide energy are investigated using a hydrostatic sigma-coordinate numerical model. A series of numerical simulations
using various horizontal grid spacings of 1/15–1/5° shows that generation of energetic baroclinic tides is restricted over
representative prominent topographic features. For example, nearly half of the diurnal (K1 and O1) baroclinic tide energy is excited along the western boundary of the North Pacific from the Aleutian Islands down to the
Indonesian Archipelago. It is also found that the rate of energy conversion from the barotropic to baroclinic tides is very
sensitive to the horizontal grid spacing as well as the resolution of the model bottom topography; the conversion rate integrated
over the global ocean increases exponentially as the model grid spacing is reduced. Extrapolating the calculated results in
the limit of zero grid spacing yields the estimate of the global conversion rate to be 1105 GW (821, 145, 102, 53 GW for M2, S2, K1, and O1 tidal constituents, respectively). The amount of baroclinic tide energy dissipated in the open ocean below a depth of 1000 m,
in particular, is estimated to be 500–600 GW, which is comparable to the mixing energy estimated by Webb and Suginohara (Nature
409:37, 2001) as needed to sustain the global overturning circulation. 相似文献
20.
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