scholarly journals THREE-DIMENSIONAL SIMULATION OF TIDAL CURRENT IN LAMPUNG BAY: DIAGNOSTIC NUMERICAL EXPERIMENTS

2010 ◽  
Vol 3 (-) ◽  
Author(s):  
Alan Frendy Koropitan ◽  
Safwan Hadi ◽  
Ivonne M.Radjawane
Keyword(s):  
Tidal Current ◽  
Lower Layer ◽  
Three Dimensional ◽  
Ocean Model ◽  
Residual Current ◽  
Global Ocean ◽  
Open Boundary ◽  
Ocean Tide ◽  
Tidal Elevation ◽  
Diagnostic Mode

Princeton Ocean Model (POM) was used to calculate the tidal current in Lampung Bay using diagnostic mode. The model was forced by tidal elevation, which was given along the open boundary using a global ocean tide model-ORITIDE. The computed tidal elevation at St. 1 and St 2 are in a good agreement with the observed data, but the computed tidal current at St 1 at depth 2 m is not good and moderate approximation is showed at depth 10 m. Probably, it was influenced by non-linier effect of coastal geometry and bottom friction because of the position of current meter, mooring closed to the coastline. Generally, the calculated tidal currents in all layers show that the water flows into the bay during flood tide and goes out from the bay during ebb tide. The tidal current becomes strong when passing through the narrow passage of Pahawang Strait. The simulation of residual tidal current with particular emphasis on predominant contituent of M2 shows a strong inflow from the western part of the bay mouth, up to the central part of the bay, then the strong residual current deflects to the southeast and flows out from the eastern part of the bay mouth. This flow pattern is apparent in the upper and lower layer. The other part flows to the bay head and froms an antic lockwise circulation in the small basin region of the bay head. The anticlockwise circulations are showed in the upper layer and disappear in the layer near the bottom. Keywords: POM, diagnostic mode, tidal current, residual current, Lampung Ba.

scholarly journals NUMERICAL CALCULATION FOR THE RESIDUAL TIDAL CURRENT IN BENOA BAY-BALI ISLAND

2010 ◽  
Vol 2 (-) ◽  
Author(s):  
GEDE HENDRAWAN ◽  
I WAYAN NUARSA ◽  
WAYAN SANDI ◽  
A.F. KOROPITAN ◽  
YASUHIRO SUGIMORI
Keyword(s):  
Boundary Condition ◽  
Tidal Current ◽  
Model Simulation ◽  
Maximum Velocity ◽  
Residual Current ◽  
Flood Tide ◽  
Open Boundary ◽  
Open Boundary Conditions ◽  
Open Boundary Condition ◽  
Tidal Elevation

Princeton Ocean Model (POM) was used to calculate the tidal current and M2-residual current in Benoa Bay using barotropic model (mode 2). The model was forced by tidal elevation, which was given along the open boundary condition using tide data prediction from Hydro-Oceanography Division-Indonesian Navy (DISHIDROS TNI-AL). The computed tidal current and residual current have been compared with both data in Benoa Bay, that are data of the open boundary of Benoa Bay and condition of Benoa Bay after developed a port and reclamation of Serangan Island. The maximum velocity of tidal current for open boundary conditions at flood tide is 0.71 m/sec, whereas at ebb tide is 0.65 m/sec and the maximum velocity after developed a port and reclamation of Serangan Island, at flood tide, is 0.69 m/sec. The simulation of residual current with particular emphasis on predominant constituent of M2 after developed a port and reclamation of Serangan Island shows a strong flow at the western part of Tanjung Benoa and Benoa Harbor and also at bay mouth between Serangan Island and Tanjung Benoa. Maximum velocity of M2-residual current is 0.0585 m/sec by the simulation and showed that the current which was produced forming two eddies in the bay of which one eddy is in the mouth of bay in southern part. The residual current for open boundary condition of bay shows four eddies circulation, one big eddies and the others small. The anticlockwise circulation occurs in the inner part of the bay. Key words: model, simulation, tidal current, residual current

scholarly journals Characteristic of Tidal Currents in the Lombok Strait Using 3D FVCOM Numerical Model

2021 ◽  
Vol 925 (1) ◽  
pp. 012002
Author(s):  
I M D Raharja ◽  
I M Radjawane ◽  
I G Hendrawan
Keyword(s):  
Tidal Current ◽  
Three Dimensional ◽  
Movement Pattern ◽  
Ocean Model ◽  
Ocean Current ◽  
Coefficient Of Determination ◽  
Open Boundary ◽  
Observation Data ◽  
Near Surface ◽  
Current Circulation

Abstract The Lombok Strait located between Bali Island and Lombok Island, Indonesia. Lombok Strait is complex area because influence by Indonesian Throughflow and influence by Tidal Current. For this case want to research about tidal current circulation and simulated using a three-dimensional baroclinic hydrodynamic numerical modelling method by Finite Volume Coastal Ocean Model (FVCOM). The study was simulated during 1-year on 2004, February. The model just simulated by barotropic condition and only influence by elevation tide in open boundary. The verification of ocean current (u and v components) from the model compare with observation data has a high coefficient of determination, i.e., 0.9, respectively. This verification result shows good agreement between model and observation data. For the result model, in the Lombok strait dominant influence by M2 semidiurnal component from Indian Ocean and K1 diurnal component from Pacific Ocean. The current circulation in the near surface dominant movement pattern from southern to northern. On the other hand, for the vertical current in 100 – 600 meter is different with near surface. The current movement from northern to southern. In the sill area have upwelling phenomenon in the north side of the sill and downwelling in south of the sill.

scholarly journals M2 tidal dynamics in the Ross Sea

2003 ◽  
Vol 15 (1) ◽  
pp. 41-46 ◽  
Author(s):  
ROBIN ROBERTSON ◽  
AIKE BECKMANN ◽  
HARTMUT HELLMER
Keyword(s):  
Continental Shelf ◽  
Ross Sea ◽  
Tidal Energy ◽  
Ocean Model ◽  
Internal Tides ◽  
Global Ocean ◽  
Tidal Dynamics ◽  
Tidal Elevation ◽  
Shelf Slope ◽  
Continental Shelf Slope

In certain regions of the Southern Ocean, tidal energy is believed to foster the mixing of different water masses, which eventually contribute to the formation of deep and bottom waters. The Ross Sea is one of the major ventilation sites of the global ocean abyss and a region of sparse tidal observations. We investigated M2 tidal dynamics in the Ross Sea using a three-dimensional sigma coordinate model, the Regional Ocean Model System (ROMS). Realistic topography and hydrography from existing observational data were used with a single tidal constituent, the semi-diurnal M2. The model fields faithfully reproduced the major features of the tidal circulation and had reasonable agreement with ten existing tidal elevation observations and forty-two existing tidal current measurements. The differences were attributed primarily to topographic errors. Internal tides were generated at the continental shelf/slope break and other areas of steep topography. Strong vertical shears in the horizontal velocities occurred under and at the edges of the Ross Ice Shelf and along the continental shelf/slope break. Estimates of lead formation based on divergence of baroclinic velocities were significantly higher than those based on barotrophic velocities, reaching over 10% at the continental shelf/slope break.

scholarly journals A parameterization of local and remote tidal mixing

2020 ◽  
Author(s):  
Casimir de Lavergne ◽  
Clément Vic ◽  
Gurvan Madec ◽  
Fabien Roquet ◽  
Amy Waterhouse ◽  
...  
Keyword(s):  
Vertical Mixing ◽  
Three Dimensional ◽  
Internal Tide ◽  
Ocean Model ◽  
Internal Tides ◽  
Tidal Mixing ◽  
Global Ocean ◽  
Energy Conserving ◽  
Energy Constrained ◽  
Lagrangian Tracking

<p>Vertical mixing is often regarded as the Achilles’ heel of ocean models. In particular, few models include a comprehensive and energy-constrained parameterization of mixing by internal ocean tides. Here, we present an energy-conserving mixing scheme which accounts for the local breaking of high-mode internal tides and the distant dissipation of low-mode internal tides. The scheme relies on four static two-dimensional maps of internal tide dissipation, constructed using mode-by-mode Lagrangian tracking of energy beams from sources to sinks. Each map is associated with a distinct dissipative process and a corresponding vertical structure. Applied to an observational climatology of stratification, the scheme produces a global three-dimensional map of dissipation which compares well with available microstructure observations and with upper-ocean finestructure mixing estimates. Implemented in the NEMO global ocean model, the scheme improves the representation of deep water-mass transformation and obviates the need for a constant background diffusivity.</p>

scholarly journals Impact of Channel Geometry and Rotation on the Trapping of Internal Tides

2007 ◽  
Vol 37 (11) ◽  
pp. 2740-2763 ◽  
Author(s):  
Sybren Drijfhout ◽  
Leo R. M. Maas
Keyword(s):  
Continental Slope ◽  
Three Dimensional ◽  
Tidal Energy ◽  
Ocean Model ◽  
Internal Tides ◽  
Open Boundary ◽  
Kelvin Wave ◽  
Channel Geometry ◽  
Channel Slope ◽  
The Cross

Abstract The generation and propagation of internal tides has been studied with an isopycnic three-dimensional ocean model. The response of a uniformly stratified sea in a channel, which is forced by a barotropic tide on its open boundary, is considered. The tide progresses into the channel and forces internal tides over a continental slope at the other end. The channel has a length of 1200 km and a width of 191.25 km. The bottom profile has been varied. In a series of four experiments it is shown how the cross-channel geometry affects the propagation and trapping of internal tides, and the penetration scale of wave energy, away from the continental slope, is discussed. In particular it is found that a cross-channel bottom slope constrains the penetration of the internal tidal energy. Most internal waves refract toward a cross-channel plane where they are trapped. The exception is formed by edge waves that carry part of the energy away from the continental slope. In the case of rotation near the continental slope, the Poincaré waves that arise in the absence of a cross-channel slope no longer bear the characteristics of the wave attractor predicted by 2D theory, but are almost completely arrested, while the right-bound Kelvin wave preserves the 2D attractor in the cross-channel plane, which is present in the nonrotating case. The reflected, barotropic right-bound Kelvin wave acts as a secondary internal wave generator along the cross-channel slope.

scholarly journals Assessment of a NEMO-based hydrodynamic modelling system for the Great Lakes

2012 ◽  
Vol 47 (3-4) ◽  
pp. 198-214 ◽  
Author(s):  
Frederic Dupont ◽  
Padala Chittibabu ◽  
Vincent Fortin ◽  
Yerubandi R. Rao ◽  
Youyu Lu
Keyword(s):  
Great Lakes ◽  
Thermal Structure ◽  
Three Dimensional ◽  
Multiscale Model ◽  
Ocean Model ◽  
Global Ocean ◽  
Central Basin ◽  
Surface Mixed Layer ◽  
Global Environmental ◽  
Modelling System

Environment Canada recently developed a coupled lake–atmosphere–hydrological modelling system for the Laurentian Great Lakes. This modelling system consists of the Canadian Regional Deterministic Prediction System (RDPS), which is based on the Global Environmental Multiscale model (GEM), the MESH (Modélisation Environnementale Surface et Hydrologie) surface and river routing model, and a hydrodynamic model based on the three-dimensional global ocean model Nucleus for European Modelling of the Ocean (NEMO). This paper describes the performance of the NEMO model in the Great Lakes. The model was run from 2004 to 2009 with atmospheric forcing from GEM and river forcing from the MESH modelling system for the Great Lakes region and compared with available observations in selected lakes. The NEMO model is able to produce observed variations of lake levels, ice concentrations, lake surface temperatures, surface currents and vertical thermal structure reasonably well in most of the Great Lakes. However, the model produced a diffused thermocline in the central basin of Lake Erie. The model predicted evaporation is relatively strong in the upper lakes. Preliminary results of the modelling system indicate that the model needs further improvements in atmospheric–lake exchange bulk formulae and surface mixed layer physics.

scholarly journals Evaluation of an operational ocean model configuration at 1/12° spatial resolution for the Indonesian seas – Part 1: Ocean physics

2015 ◽  
Vol 8 (8) ◽  
pp. 6611-6668 ◽  
Author(s):  
B. Tranchant ◽  
G. Reffray ◽  
E. Greiner ◽  
D. Nugroho ◽  
A. Koch-Larrouy ◽  
...  
Keyword(s):  
Ocean Circulation ◽  
Satellite Data ◽  
Water Mass ◽  
Ocean Model ◽  
Internal Tides ◽  
Global Ocean ◽  
Open Boundary ◽  
Indonesian Throughflow ◽  
The South ◽  
Water Mass Transformation

Abstract. INDO12, a 1/12° regional version of the NEMO physical ocean model covering the whole Indonesian EEZ has been developed and is now running every week in the framework of the INDESO project (Infrastructure Development of Space Oceanography) implemented by the Indonesian Ministry of Marine Affairs and Fisheries. The initial hydrographic conditions as well as open boundary conditions are derived from the operational global ocean forecasting system at 1/4° operated by Mercator Ocean. Atmospheric forcing fields (3 hourly ECMWF analyses) are used to force the regional model. INDO12 is also forced by tidal currents and elevations, and by the inverse barometer effect. The turbulent mixing induced by internal tides is taken into account through a specific parameterization. In this study we evaluate the model skill through comparisons with various datasets including outputs of the parent model, climatologies, in situ temperature and salinity measurements, and satellite data. The simulated and altimeter-derived Eddy Kinetic Energy fields display similar patterns and confirm that tides are a dominant forcing in the area. The volume transport of the Indonesian ThroughFlow is in good agreement with the INSTANT current meter estimates while the transport through Luzon Strait is, on average, westward but probably too weak. Significant water mass transformation occurs along the main routes of the Indonesian Throughflow (ITF) and compares well with observations. Vertical mixing is able to erode the South and North Pacific subtropical waters salinity maximum as seen in TS diagrams. Compared to satellite data, surface salinity and temperature fields display marked biases in the South China Sea. Altogether, INDO12 proves to be able to provide a very realistic simulation of the ocean circulation and water mass transformation through the Indonesian Archipelago. A few weaknesses are also detected. Work is on-going to reduce or eliminate these problems in the second INDO12 version.

Three-Dimensional Physical Environment Modelling for Integrated Multi-Trophic Aquaculture (IMTA) Implementation in Onagawa Bay, Japan

2019 ◽  
Author(s):  
Jinxin Zhou ◽  
Takero Yoshida ◽  
Junbo Zhang ◽  
Sanggyu Park ◽  
Daisuke Kitazawa
Keyword(s):  
Environmental Sustainability ◽  
Physical Environment ◽  
Three Dimensional ◽  
Open Water ◽  
Ocean Model ◽  
Observation Data ◽  
Public Attention ◽  
Tidal Elevation ◽  
Miyagi Prefecture ◽  
Environment Study

Abstract Continually increasing demands on aquaculture products drive the current monoculture to upgrade and upscale because of not only economic but environmental sustainability reasons. Over the past decade, open water integrated multi-trophic aquaculture (IMTA) practiced as a potential alternative has been demonstratively illustrated from both scientific and public attention. Basing on previous studies of this synergistic aquaculture system, we, here, studied the physical environment in Onagawa Bay as the cornerstone for further IMTA implementation. Onagawa Bay locates in Miyagi Prefecture, Japan, and because of its mature practice on polyculture, it is recognized as a suitable site for IMTA. Unfortunately, the earthquake and tsunami in 2011 caused a huge uncertainty on physical environment changes. Still insufficient researches have been conducted on physical environment study, especially through modelling method. Here, adopting the three-dimensional Marine Environmental Committee (MEC) ocean model, we described the setup and validation for Onagawa Bay in this research. At the present stage, simulation results can best fit observation data on the tidal elevation with the correlation coefficient between observed and simulated tidal elevation reaching 0.96, captured the main characteristic of flow velocity, and exhibited homogenous tendency towards water temperature. Furthermore, through the plot of the residual velocity field and statistical seasonal velocity distribution, potential aquaculture configuration has been discussed spatio-temporally on the hypothesis that high current speeds contribute to the further implementation.

scholarly journals Ocean tides under the Filchner-Ronne Ice Shelf, Antarctica

1996 ◽  
Vol 23 ◽  
pp. 217-225 ◽  
Author(s):  
M. J. Smithson ◽  
A. V. Robinson ◽  
R. A. Flather
Keyword(s):  
Friction Coefficient ◽  
Ocean Model ◽  
Global Ocean ◽  
Open Boundary ◽  
Open Boundary Conditions ◽  
Ocean Tides ◽  
Ice Shelf ◽  
Grounding Line ◽  
Preliminary Study ◽  
Tidal Constituents

A depth-averaged finite-difference numerical model has been used to make a preliminary study of the tides under the Filchner–Ronne Ice Shelf. Open boundary conditions were specified using the global ocean model of Schwiderski. Tidal constituents for the two principal semi-diurnal constituents M2 and S2, and the two principal diurnal constituents Ο1 and K1 were extracted from computed sea-surface elevations by harmonic analysis. Measured values near to the grounding line could only be reproduced satisfactorily by increasing the bottom friction coefficient under the ice to 50 times the open-ocean value. This destroys any agreement near the ice front or at pelagic sites. It is thought that a friction coefficient which varies with distance under the ice would be able to reproduce better all the available measurements. More tidal measurements are required to validate any model of the region with model experiments being used to help pinpoint possible sites for instrument deployment.

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