Large-amplitude internal Kelvin waves trapped off Split (Middle Adriatic Sea)     

Ivica Vilibi&#x;  Vlado Dadi&#x;  Hrvoje Mihanovi&#x; 《Estuarine, Coastal and Shelf Science》2004,61(4):623-630

The paper documents the occurrence of long-period internal Kelvin waves in Split Channel in spring 2002. The analyses were performed on thermohaline and current data measured at three moorings and one hydrographic section. The internal oscillation had a period of 5–6 days, being larger just after the generation which was probably excited by the alongshore Sirocco wind. The recorded current amplitude was up to 0.3 m s⁻¹ in the surface layer, while the observed pycnocline displacement was 10–15 m. The oscillation was reproduced by one-dimensional two-layered model of a channel, imposing nodal lines at its entrances. Cross-shore properties of the oscillation, such as observed offshore decrease in pycnocline amplitude, are explained by the dynamics of an internal Kelvin wave propagating along channel boundaries, because the internal Rossby radius is smaller than the width of the channel. Conclusively, the observed oscillation probably represents the fundamental mode of internal waves trapped in the channel complex off Split.  相似文献   

基于余水位配置的海洋潮汐推算研究   总被引：4，自引：1，他引：4  

侯世喜  黄辰虎  陆秀平  黄谟涛  欧阳永忠  孙雪洁 《海洋测绘》2005,25(6):29-33

基于余水位的配置模型,利用长期验潮站实测水位结合临近短期验潮站天文潮位来恢复短期站的实际水位,并对其进行误差分析,证明基于余水位配置的海洋潮汐推算的可行性与实用性.  相似文献   

青岛海湾大桥对胶州湾潮汐、潮流及余环流的影响预测——Ⅰ.胶州湾及邻近海域的潮流     

孙英兰  孙长青  王学昌  田晖  陈时俊 《中国海洋大学学报(自然科学版)》1994,(Z1)

根据崂山头、朝连岛、灵山岛一个月的潮位资料,采用三角形网格的分步杂交方法,建立了胶州湾及邻近海域的二维变边界潮流数值模型。并模拟了大、中、小潮三种潮汛条件下的潮流场,水位场及余流场。得出了胶州湾高潮水域面积、潮间带面积,湾口累积流通量等有关参数。  相似文献   

非均匀风场作用下太湖风成流风涌水的数值模拟及验证   总被引：7，自引：0，他引：7  

逄勇  王谦谦 《海洋湖沼通报》1994,(4):9-15

本文采用浅水波方程数值模式，考察太湖局地风场的影响，模拟了太湖风成流，风涌水的变化情况，模拟结果与实测值符合较好，另外，将实测风场资料代入模式计算，结果表明，模拟对风涌水有较好的预报能力，流向流速的计算值与实测值在态势上较为一致。  相似文献   

南海深水区季平均海流的诊断计算     

章凡  黄企洲  王文质  李毓湘  周国荣 《热带海洋学报》1994,(3)

根据南海温、盐度历史观测数据的季平均值和季平均风应力场,采用三维非线性海流诊断模式,对南海大陆架外深水海区四季平均流场进行了数值模拟计算。所得的南海四季环流总趋势以及一些中小尺度的涡旋现象,同已有的一些研究结果基本相符。此外,还较好地反映了南海海流的季节变化特征和流场在不同深度的分布特点。  相似文献   

渤海中部长期流的观测与余流分析   总被引：8，自引：0，他引：8  

匡国瑞  张琦 《海洋湖沼通报》1991,(2):1-11

本文用渤中8号平台长期流观测取得的资料,分析了余流的变化特征。同时,用日平均流与日平均风的互相关函数,探讨了流与风的关系。  相似文献   

Structure and Transport of the Agulhas Current and Its Temporal Variability     

Harry?L.?BrydenEmail author  Lisa?M.?Beal  Louise?M.?Duncan 《Journal of Oceanography》2005,61(3):479-492

Using a year-long moored array of current meters and well-sampled synoptic sections, we define the variability and mean structure and transport of the Agulhas current. Nineteen current meter records indicate that time scales for the temporal variability in the alongshore and offshore velocities are 10.2 and 5.4 days, respectively. Good vertical correlation exists between the alongshore or onshore velocity fluctuations, excluding the Agulhas Undercurrent. The lateral scale for the thermocline Agulhas current is about 60 km and the onshore velocity correlations are positive throughout the Agulhas Current system. Mean velocities from the array determine that the offshore edge of the Agulhas Current lies at 203 km and the penetration depth is 2200 m offshore of the Undercurrent. Hence, daily averaged velocity sections, determined by interpolation and extrapolation of current meter locations, for a 267-day period, from the surface to 2400 m depth and from the coast out to 203 km offshore encompass the main features of the Agulhas Current system. The Agulhas current is generally found close to the continental slope, within 31 km of the coast for 211 of 267 days. There are only five days when the core of the current is found offshore at 150 km. Total transport is always poleward, varying from −121 to −9 Sv, with maximum transport occurring when the core is 62 km from the coast. Average total transport for the 267 day period is −69.7 Sv; the standard deviation in daily transport values is 21.5 Sv; and the mean transport has an estimated standard error of 4.3 Sv. The Agulhas Undercurrent, which hugs the continental slope below the zero velocity isotach, has an average equatorward transport of 4.2 Sv, standard deviation of 2.9 Sv and an estimated standard error of 0.4 Sv. Transports from the moored array are in reasonable agreement with transport results from synoptic sections. Based on time series measurements at about 30° latitude in each ocean basin, the Agulhas Current is the largest western boundary current in the world ocean.  相似文献   

TOPEX/Poseidon and Jason Equatorial Sea Surface Slope Anomaly in the Atlantic in 2002: Comparison with Wind and Current Measurements at 23W     

C. PROVOSt  S. ARNAULt  N. CHOUAIb  A. Kartavtseff  L. Bunge  E. Sultan 《Marine Geodesy》2004,27(1):31-45

A time series of velocity profile in the upper 150 m of the equatorial Atlantic was gathered at 23W in 2002 within the PIRATA program. It constitutes the first time series of near surface current measurements simultaneous with altimetric data in the equatorial Atlantic. The surface slope anomaly along the equator is computed from satellite altimetry, and, as a proxy for the pressure gradient along the equator, compared with the wind and near surface current data. In a first step, a time series of the surface slope anomaly along the equator in the Atlantic is computed from the 10-year-long TOPEX/Poseidon sea level anomalies. A sensitivity study establishes the robustness of the calculation. Apart from a 15 cm bias, the equatorial sea surface slope anomalies estimated either from TOPEX/Poseidon or from Jason over the 6-month overlap (Feb.-Aug. 2002) do not reveal drastic differences. We produce two sea surface slope anomaly composite time series for 2002 (one with T/P data, the other with Jason data during the commissioning phase) and compare them to the wind and velocity data at 23W. As expected, the near surface velocity and depth of the upper limit of the equatorial undercurrent (EUC) are extremely well correlated with the surface pressure gradient anomaly. 10-year-long time series of altimetry-derived zonal sea surface slope anomaly and ECMWF ERA40 wind stress are also well correlated. They exhibit similar spectral content and similar anomalous years. This is a first step towards a full analysis of the EUC dynamics using altimetry, PIRATA data (near surface current and subsurface thermohaline structure) and model. These initial comparisons reinforce the utility of Jason measurements for continuing the 10-year and highly accurate TOPEX/Poseidon time series for study of equatorial signals.  相似文献   

Input of Glaciomarine Sediments along the East Antarctic Continental Margin; Depositional Processes on the Cosmonaut Sea Continental Slope and Rise and a Regional Acoustic Stratigraphic Correlation from 40° W to 80° E     

B. Kuvaas  Y. Kristoffersen  J. Guseva  G. Leitchenkov  V. Gandjukhin  G. Kudryavtsev 《Marine Geophysical Researches》2004,25(3-4):247-263

Multichannel seismic reflection data from the Cosmonaut Sea margin of East Antarctica have been interpreted in terms of depositional processes in the continental slope and rise area. A major sediment lens is present below the upper continental rise along the entire Cosmonaut Sea margin. The lens probably consists of sediments supplied from the shelf and slope, being constantly reworked by westward flowing bottom currents, which redeposited the sediments into a large scale drift deposit prior to the main glaciogenic input along the margin. High-relief semicircular or elongated depositional structures are also found on the upper continental rise stratigraphically above the regional sediment lens, and were deposited by the combined influence of downslope and alongslope sediment transport. On the lower continental rise, large-scale sediment bodies extend perpendicular to the continental margin and were deposited as a result of downslope turbidity transport and westward flowing bottom currents after initiation of glacigenic input to the slope and rise. We compare the seismostratigraphic signatures along the continental margin segments of the adjacent Riiser Larsen Sea, the Weddell Sea and the Prydz Bay/Cooperation Sea, focussing on indications that may be interpreted as a preglacial-glaciomarine transition in the depositional environment. We suggest that earliest glaciogenic input to the continental slope and rise occurred in the Prydz Bay and possibly in the Weddell Sea. At a later stage, an intensification of the oceanic circulation pattern occurred, resulting in the deposition of the regional plastered drift deposit along the Cosmonaut Sea margin, as well as the initiation of large drift deposits in the Cooperation Sea. At an even later stage, possibly in the middle Miocene, glacial advances across the continental shelf were initiated along the Cosmonaut Sea and the Riiser Larsen Sea continental margins.  相似文献   

Dynamics of the turbidity maximum in King Sound, tropical Western Australia   总被引：1，自引：0，他引：1  

E. Wolanski  S. Spagnol 《Estuarine, Coastal and Shelf Science》2003,56(5-6):877-890

King Sound is a 100-km-long embayment located in tropical northwestern Australia with a spring tidal range of 11 m. This is the second largest tide in the world after the Bay of Fundy in Canada. Intertidal areas cover about 800 km². The upper reaches of the sound are turbid with fine suspended sediment concentration reaching 3 kg m⁻³. Field studies of the dynamics of water and fine sediment were carried out in the dry seasons of 1997 and 1998. The tide was a propagating wave, shoaling and dissipating by friction as it entered the sound. This mode of propagation generated an asymmetric tidal current with a stronger current at flood than at ebb. An evaporation-driven salinity maximum zone was found in the upper reaches of the sound, and this was also where the turbidity maximum occurred. Tidal pumping by the tidal asymmetry and, possibly, the biological filter formed by muddy marine snow, trapped the fine sediment in the upper regions of King Sound. Wind-driven waves contributed significantly to entrainment of bottom fine sediment, possibly through wave pumping of the sediment and not wave-induced orbital velocities. Field data suggest that erosion of bottom fine sediment was proportional to the sixth power of the tidal current and the third power of the wave height.  相似文献