基于船载ADCP观测对罗源湾湾口断面潮流及余流的分析   总被引：2，自引：1，他引：1  

姚志刚  鲍献文  李娜  李希彬  宋军  万凯 《海洋学报》2012,34(6):1-10

基于对罗源湾可门水道的25 h连续走航ADCP观测,成功构建了沿走航断面共12个站位的连续海流时间序列,并对这些站位的潮流、余流以及潮通量等进行了分析。结果表明可门水道内的潮流为正规半日潮流,驻波性质明显,涨潮首先出现在水道中下层而退潮则首先发生在水道上层。水道内的潮流为往复流,水道南部M₂分潮流流速较大,并且其倾角自北向南逐渐增加。此外,水道两端的浅水区域内浅水分潮M₄振幅较显著。可门水道内余流呈现出两层结构,20 m以浅余流沿东北向流出海湾,并且出流的核心位置偏南,而20 m以深的余流沿西南向流入湾内,入流的流核位于偏北的近底层区域。对潮通量的积分计算表明通过可门水道进入罗源湾的潮通量约为4.81×108 m3。  相似文献   

深海潜标ADCP 的实时数据传输   总被引：2，自引：2，他引：0  

赵忠生  袁志伟  黄磊  李延刚  韩雪双  杨宝起  陈海涛 《海洋科学》2012,36(8):94-97

深海潜标观测是深海观测获取长周期海洋科学数据的重要调查手段,由于深海海域环境非常复杂,潜标易丢失或终止正常工作,造成重大损失.本研究基于铱星卫星数据通信模块,开发与深水潜标上安装的RDt 75k ADCP相匹配的数据解析压缩软硬件,建立一套远程实时获取潜标ADCP数据的传输系统,实现对深海潜标ADCP的实时监测.  相似文献   

A sediment fluxes investigation for the 2-D modelling of large river morphodynamics     

《Advances in water resources》2015

A complete understanding of alluvial-bed dynamics is desirable for evaluating a variety of issues related to water resources.Sediment fluxes were investigated in a bifurcation of the large Parana River near Rosario, Argentina. The backscatter estimations from the Doppler profilers provided the suspended load of the sediment forming the riverbed. An echo-sounder was applied to track the dunes yielding the bed-load estimation.Aiming to show the usefulness of the recorded data, a 2-D numerical code was applied to the 10-km long and 2-km wide Rosario reach. The morphodynamic module was un-coupled from the hydrodynamics assessment, which enabled the long-term prediction of the river morphology accounting for the hydrological yearly variation with a quasi-steady approach.Numerical experiments were performed to test the sensitivity of the hydrodynamic model to the computational time-step and mesh size, to test the un-coupling scheme performance regarding the full-dynamic modelling, to test the accuracy of the sediment transport formulae based on the field evidence and, finally, to provide guidance to properly fix the model parameters.  相似文献   

Estimating longitudinal dispersion in rivers using Acoustic Doppler Current Profilers     

Chaopeng Shen  Jie Niu  Eric J. Anderson  Mantha S. Phanikumar 《Advances in water resources》2010

The longitudinal dispersion coefficient (D) is an important parameter needed to describe the transport of solutes in rivers and streams. The dispersion coefficient is generally estimated from tracer studies but the method can be expensive and time consuming, especially for large rivers. A number of empirical relations are available to estimate the dispersion coefficient; however, these relations are known to produce estimates within an order of magnitude of the tracer value. The focus of this paper is on using the shear-flow dispersion theory to directly estimate the dispersion coefficient from velocity measurements obtained using an Acoustic Doppler Current Profiler (ADCP). Using tracer and hydrodynamic data collected within the same river reaches, we examined conditions under which the ADCP and tracer methods produced similar results. Since dead zones / transient storage (TS) are known to influence the dispersion coefficient, we assessed the relative importance of dead zones in different stream reaches using two tracer-based approaches: (1) TS modeling which explicitly accounts for dead zones and (2) the advection–dispersion equation (ADE) which does not have separate terms for dead zones. Dispersion coefficients based on the ADE tend to be relatively high as they describe some of the effects of dead zones as well. Results based on the ADCP method were found to be in good agreement with the ADE estimates indicating that storage zones play an important role in the estimated dispersion coefficients, especially at high flows. For the river sites examined in this paper, the tracer estimates of dispersion were close to the median values of the ADCP estimates obtained from multiple datasets within a reach. The ADCP method appears to be an excellent alternative to the traditional tracer-based method if care is taken to avoid spurious data and multiple datasets are used to compute a distance-weighted average or other appropriate measure that represents reach-averaged conditions.  相似文献   

Low-frequency current variability observed at the shelfbreak in the northeastern Gulf of Mexico: November 2004–May 2005     

M.R. Carnes  W.J. TeagueE. Jarosz 《Continental Shelf Research》2008

Fourteen acoustic Doppler current profilers (ADCPs) were deployed on the shelf and slope for 1 year just west of the DeSoto Canyon in the Northeastern Gulf of Mexico by the Naval Research Laboratory (NRL) as part of its Slope to Shelf Energetics and Exchange Dynamics (SEED) project. The winter and spring observations are discussed here in regards to the low-frequency current variability and its relation to wind and eddy forcing. Empirical orthogonal function (EOF) analyses showed that two modes described most of the current variability. Wind-forced variability of the along-shelf flow was the main contributor in Mode 1 while eddies contributed much of the variability in Mode 2. Wind-stress controlled currents on the shelf and slope at time scales of about a week. On longer time scales, variations in the currents on both the outer shelf and slope appear to be related to seasonal variations in the time-cumulated wind stress curl. Winds were dominant in driving the along-shelf transports, particularly along the slope. However, the effective wind stress component was found to be aligned with the west Florida shelf direction rather than the local shelf direction. Eddy intrusions, which were more numerous in winter and spring than in summer and fall, and winds were found to contribute significantly to cross-shelf exchange processes.  相似文献   

Long-term evolution of sand waves in the Marsdiep inlet. II: Relation to hydrodynamics     

Maarten C. Buijsman  Herman Ridderinkhof 《Continental Shelf Research》2008

A discussion is presented about the mechanisms that govern the spatial and seasonal variability in sand-wave height and migration speed in the 4 km wide Marsdiep tidal inlet, the Netherlands. Since 1998, current velocities and water depths have been recorded with an ADCP that is mounted under the ferry ‘Schulpengat’. In this paper, the current measurements were used to explain the sand-wave observations presented in Buijsman and Ridderinkhof [this issue. Long-term evolution of sand waves in the Marsdiep inlet. I: high-resolution observations. Continental Shelf Research, doi:10.1016/j.csr.2007.10.011]. Across nearly the entire inlet, the sand waves migrate in the flood direction. In the flood-dominated southern part of the inlet, the ‘measured’ (i.e. based on sand-wave shape and migration speed) and predicted bedload transport agree in direction, magnitude, and trends, whereas in the ebb-dominated northern part the predicted bedload and suspended load transport is opposite to the sand-wave migration. In the southern part, 55% of the bedload transport is due to tidal asymmetries and 45% due to residual currents. In addition to the well-known tidal asymmetries, asymmetries that arise from the interaction of _M2${\mathrm{M}}_2$ and its overtides with _S2${\mathrm{S}}_2$ and its compound tides are also important. It is hypothesised that in the northern part of the inlet the advection of suspended sand and lag effects govern the sand-wave migration. The relative importance of suspended load transport also explains why the sand waves have smaller lee-slope angles, are smaller, more rounded, and more three-dimensional in the northern half of the inlet. The sand waves in this part of the inlet feature the largest seasonal variability in height and migration speed. This seasonal variability may be attributed to the tides or a seasonal fluctuation in fall velocity. In both cases sediment transport is enhanced in winter, increasing sand-wave migration and decreasing sand-wave height. The influence of storms and estuarine circulation on the sand-wave variability is negligible.  相似文献   

长江口悬沙动力特征与输运模式   总被引：5，自引：0，他引：5  

高建华  汪亚平  潘少明  王爱军 《海洋通报》2005,24(5):8-15

本项研究用ADCP在长江河口进行高频、高分辨率三维流速和声学浊度的定点观测,通过对定点站位潮周期内的悬沙浓度、流速和盐度的分析,计算悬沙输运率;悬沙输运机制分析表明平流作用、斯托克斯漂移效应在悬沙输运中占据主导地位.此外,从河口内向河口外,潮周期内的水动力特征与悬沙净输运具有明显的地域性差异,主要表现在悬沙输送的贡献因子、盐度的垂向混合和分布特征、垂向流速等方面.在拦门沙下游和口外地区,悬沙均向西、北方向输送,而拦门沙上游则向东、南方向输送.这种悬沙输运格局,对于长江口拦门沙及附近最大浑浊带的形成有着重要的作用.  相似文献   

Mesoscale Eddies Observed by TOLEX-ADCP and TOPEX/POSEIDON Altimeter in the Kuroshio Recirculation Region South of Japan   总被引：1，自引：0，他引：1  

Naoto Ebuchi  Kimio Hanawa 《Journal of Oceanography》2000,56(1):43-57

Mesoscale eddies in the Kuroshio recirculation region south of Japan have been investigated by using surface current data measured by an Acoustic Doppler Current Profiler (ADCP) installed on a regular ferry shuttling between Tokyo and Chichijima, Bonin Islands, and sea surface height anomaly derived from the TOPEX/POSEIDON altimeter. Many cyclonic and anticyclonic eddies were observed in the region. Spatial and temporal scales of the eddies were determined by lag-correlation analyses in space and time. The eddies are circular in shape with a diameter of 500 km and a temporal scale of 80 days. Typical maximum surface velocity and sea surface height anomaly associated with the eddies are 15–20 cm s^–1 and 15 cm, respectively. The frequency of occurrence, temporal and spatial scales, and intensity are all nearly the same for the cyclonic and anticyclonic eddies, which are considered to be successive wave-like disturbances rather than solitary eddies. Phase speed of westward propagation of the eddies is estimated as 6.8 cm s^–1, which is faster than a theoretical estimate based on the baroclinic first-mode Rossby wave with or without a mean current. The spatial distribution of sea surface height variations suggests that these eddies may be generated in the Kuroshio Extension region and propagate westward in the Kuroshio recirculation region, though further studies are needed to clarify the generation processes.  相似文献   

Southwestward intrusion of korea strait bottom cold water observed in 2003 and 2004     

Chang?-Woong?ShinEmail author  Cheolsoo?Kim  Sang?-Kyung?Byun  Dongchull?Jeon  Sang?-Chull?Hwang 《Ocean Science Journal》2006,41(4):291-299

Hydrographic surveys were carried out four times in the western channel of the Korea Strait in March and August 2003 and in June and November 2004. The bottom cold water, which was lower than 10°C, appeared in the channel trough except in March 2003. It flowed southwestward along the shelf of Korean coasts in August 2003 and in November 2004. The width and the maximum speed of the intrusion current were about 20 km and approximately 25 cm s^-1, respectively, off Ulsan, Korea. The volume transport of the bottom cold water was estimated 0.019 Sv (Sv≡10⁶ m³ s^-1) in August 2003 and 0.026 Sv in November 2004.  相似文献   

Study on Representative Vertical Method for Tidal Discharge Processing of Xuliujing Gauging Station in Yangtze River Estuary     

GUO Jian  XV Jian  ZHU Qiao-yun  GUO Jian  LIU Gui-ping  XV Jian 《水文》2008,28(4)

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