Tidal Wave Research Articles

Tide-modulated river discharge division in the Ganges-Brahmaputra-Meghna delta channel network, Bangladesh

Study RegionThe Ganges-Brahmaputra-Meghna (GBM) delta in Bangladesh Study FocusThe flow distribution in a deltaic channel network is complicated by tidal wave propagation. We use a 2DH numerical model to investigate the variability of the tide-modulated seasonal, subtidal, intratidal and residual divided discharges. New Hydrological InsightsSimulations show that the divided subtidal discharges and correlated subtidal water levels display remarkable fortnightly fluctuations in dry months, whereas they are heavily distorted by the rapid rising & falling limbs of main stream flood waves in wet months. A subtidal water circulation that net water is transported from the tributaries to the main stream maintains at lower upstream discharges but is reversed by larger upstream discharges. With a series of increasing upstream riverine discharges routing downstream, the subtidal inflows experience a phase shift in the fortnightly cycles, in which the inflow peaks gradually move from spring tide to neap tide; moreover, the residual inflows demonstrate a non-monotonic variability, i.e. enlargements to the river-only case occur at two particular upstream discharges, compared to the reduced residual inflows at the majority of upstream discharges. These characteristic processes are explained by the mean amplitudes and phase relationships of tidal species (D1,D2,D4,D1/14) and the increasing dominance of river discharge over tidal wave. Our findings deepen the understandings of the complex nonlinear river-tide interactions in a deltaic channel network.

Research on field testing and assessment technology of ocean energy converters

The field testing and assessment technology for evaluating the power performance and power quality performance of an ocean energy converter plays a crucial role in enhancing the power generation capabilities of the tested converter. Moreover, it facilitates the advancement and growth of the ocean energy converter industry. On the basis of analyzing the current research and development status and test requirements of tidal energy converters and wave energy converters around the world, a field testing and assessment method for power performance and power quality performance of ocean energy converters was explored, measurement requirements for tidal parameters, wave parameters and electric parameters were proposed, and field testing systems for power performance and power quality performance of ocean energy converters were investigated and constructed. The field testing systems and assessment methods investigated in the present study were used to conduct field testing work on a tidal energy converter and a wave energy converter, and the test data was processed and analyzed to obtain the power characteristics performance and power quality characteristics performance of the tested ocean energy converters. The present study not only provides a field testing and assessment technology for ocean energy converters, but also a reference for future field testing and assessment work of ocean energy converters.

INVENTION OF FLOATING GATES BASED ON ARTIFICIAL INTELLIGENCE DESIGING FOR MARED DAM AND WATERWAY

The Karun River is oriented from Zagros Mountains. In the MARED pump station, flat dam and waterway should be constructed to prohibit the intrusion of Persian Gulf tide waves. First layout belonged to SWECO consulting engineering in 1975 that were decided to build ship lock and dam by cubic concrete boxes as the main structure. Dam bed should be stabled to pass barges through waterway (500 tons capacity) and concrete piles ($30ˏ000ˏ000 in 2010). Second scheme of dam and waterway were designed to make with steel pipe piles, steel gates, concrete walls and embankment at 2018 more than $100ˏ000ˏ000 cost. Invention design could be replaced in the MARED dam and waterway. Floating steel gates must be rotated vertically by AI Designing. Steel gates shall be designed to add air inside the gate body. Movable gates are simulated through the fish swim bladder to operate the system that can be adapt with the water fluctuation. Air could be inserted into the simulated swim bladder by the compressor to buoy the gates. Also, it can be discharge the air automatically when the water level needs to be down. The effective depth is more than +18m therefore floating gates should be made by the hollow steel box. The total cost of the third scenarios may be estimated less than $10ˏ000ˏ000 for AID at 2023. Main dam was made to reduce costs using the pipes piles and buoyancy gates. Sediment flow can easily pass through the dam bottom and monitoring floating gates.

Measuring tidal dissipation in giant planets from tidal circularization

ABSTRACT In this project, we determined the constraints on the modified tidal quality factor, $Q_{\rm pl}^{\prime }$, of gas-giant planets orbiting close to their host stars. We allowed $Q_{\rm pl}^{\prime }$ to depend on tidal frequency, accounting for the multiple tidal waves with time-dependent frequencies simultaneously present on the planet. We performed our analysis on 78 single-star and single-planet systems, with giant planets and host stars with radiative cores and convective outer shells. We extracted constraints on the frequency-dependent $Q_{\rm pl}^{\prime }$ for each system separately and combined them to find general constraints on $Q_{\rm pl}^{\prime }$ required to explain the observed eccentricity envelope while simultaneously allowing the observed eccentricities of all systems to survive to the present-day. Individual systems do not place tight constraints on $Q_{\rm pl}^{\prime }$. However, since similar planets must have similar tidal dissipation, we require that a consistent, possibly frequency-dependent, model must apply. Under that assumption, we find that the value of $\log _{10}Q_{\rm pl}^{\prime }$ for HJs is 5.0 ± 0.5 for the range of tidal period from 0.8 to 7 d. We did not see any clear sign of frequency dependence of $Q_{\rm pl}^{\prime }$.

Modelling the effect of the tidal cycle on the high phytoplankton biomass area of Cape Trafalgar (SW Iberian Peninsula)

Physical–biological interactions in the ocean are known to be crucial for understanding ecosystem processes. This is particularly relevant in the highly dynamic coastal regions, where the biogeochemical processes associated with higher-frequency perturbations such as tidal waves play a key role in primary production. In this study, we examine the influence of the tide-topography interaction on the high productivity area of Cape Trafalgar (NW limit of the Strait of Gibraltar, Iberian Peninsula) using a high-resolution ocean circulation model coupled to an ecosystem model. The obtained results highlight the relevance of the tidal cycle explaining the high phytoplankton biomass that characterises this region through an active and periodic forcing, resulting in a pulsating upwelling system. Our model shows that the interaction of the westward zonal component of the tidal current (uvel) with the submarine ridge (i.e., Barbate High) that characterises this region, which is perpendicular to the coast, results in the pumping of deep, cold, salty, and nutrient-rich waters to the well-illuminated subsurface waters, fuelling phytoplankton growth. At the same time, the interaction of the westward tidal current with the ridge leads to the development of a cyclonic eddy, which enables the redistribution of the upwelled waters over and to the east of Barbate High. The fortnightly tidal period has been identified as the most influential because (an effective) tidal-pumping process only takes place when the westward uvel is ∼ 0.42 m s−1, a condition attained between ∼ 3 days before and after the moment of maximum tidal flow during spring tides. Simultaneously, the energy and the associated horizontal and vertical mixing of the cyclonic gyre also vary with the tidal cycle, being stronger during spring tides. Both tidally driven processes, i.e., the cyclical upslope advection of deep nutrient-rich water and the influence of the cyclonic gyre, are the main mechanisms that lead to the development of a persistent phytoplankton-rich tongue over Barbate High. Consequently, Cape Trafalgar acts as a source of nutrient- and phytoplankton-rich waters to the surrounding waters.

Constraints on tidal quality factor in Kepler eclipsing binaries using tidal synchronization: a frequency-dependent approach

ABSTRACT Tidal dissipation in binary systems is the primary source for synchronization and circularization of the objects in the system. The efficiency of the dissipation of tidal energy inside stars or planets results in significant changes in observed properties of the binary system and is often studied empirically using a parameter, commonly known as the modified tidal quality factor (${Q_{\star }^{\prime }}$). Though often assumed constant, in general that parameter will depend on the particular tidal wave experiencing the dissipation and the properties of the tidally distorted object. In this work, we study the frequency dependence of ${Q_{\star }^{\prime }}$ for Sun-like stars. We parametrize ${Q_{\star }^{\prime }}$ as a saturating power law in tidal frequency and obtain constraints using the stellar rotation period of 70 eclipsing binaries observed by Kepler. We use Bayesian analysis to account for the uncertainties in the observational data required for tidal evolution. Our analysis shows that ${Q_{\star }^{\prime }}$ is well constrained for tidal periods >15 d, with a value of ${Q_{\star }^{\prime }}\sim 10^8$ for periods >30 d and a slight suggested decrease at shorter periods. For tidal periods <15 d, ${Q_{\star }^{\prime }}$ is no longer tightly constrained, allowing for a broad range of possible values that overlaps with the constraints obtained using tidal circularization in binaries, which point to much more efficient dissipation: ${Q_{\star }^{\prime }}\sim 10^6$.

On the energetics of a tidally oscillating convective flow

ABSTRACT This paper examines the energetics of a convective flow subject to an oscillation with a period $t_{\rm osc}$ much smaller than the convective time-scale $t_{\rm conv}$, allowing for compressibility and uniform rotation. We show that the energy of the oscillation is exchanged with the kinetic energy of the convective flow at a rate $D_R$ that couples the Reynolds stress of the oscillation with the convective velocity gradient. For the equilibrium tide and inertial waves, this is the only energy exchange term, whereas for p modes there are also exchanges with the potential and internal energy of the convective flow. Locally, $\left| D_R \right| \sim u^{\prime 2} / t_{\rm conv}$, where $u^{\prime}$ is the oscillating velocity. If $t_{\rm conv} \ll t_{\rm osc}$ and assuming mixing length theory, $\left| D_R \right|$ is $\left( \lambda_{\rm conv} / \lambda_{\rm osc} \right)^2$ smaller, where $\lambda_{\rm conv}$ and $\lambda_{\rm osc}$ are the characteristic scales of convection and the oscillation. Assuming local dissipation, we show that the equilibrium tide lags behind the tidal potential by a phase $\delta(r) \sim r \omega_{\rm osc} / \left( g(r) t_{\rm conv}(r) \right)$, where g is the gravitational acceleration. The equilibrium tide can be described locally as a harmonic oscillator with natural frequency $\left( g/r \right)^{1/2}$ and subject to a damping force $-u^{\prime}/t_{\rm conv}$. Although $\delta(r)$ varies by orders of magnitude through the flow, it is possible to define an average phase shift $\overline{\delta }$ which is in good agreement with observations for Jupiter and some of the moons of Saturn. Finally, $1 / \overline{\delta }$ is shown to be equal to the standard tidal dissipation factor.

Measurements and modeling of water levels, currents, density, and wave climate on a semi-enclosed tidal bay, Cádiz (southwest Spain)

Abstract. Estuarine dynamics are highly complex as a result of the temperature and salinity gradients, as well as the multiple interactions between atmospheric, maritime, and hydrological forcing agents. Given the environmental and socioeconomic importance of estuaries and their current and future threats due to human interventions and climate change, it is of vital importance to characterize these dynamics, monitor their evolution, and quantify the expected impacts derived from climate change. This paper presents a hybrid database combining data obtained in six field surveys (in 2012, 2013, and 2015) and results from a physically based 3D numerical model for the Bay of Cádiz (southern Spain), a highly anthropized mesotidal estuary. The 3D dataset includes water levels, currents, density, and wave climate, allowing for an analysis of bay dynamics at different timescales ranging from intratidal processes to seasonal variabilities. The results offer an example of the potential uses of the dataset and include (1) an assessment of the spatial and seasonal variability of the estuarine dynamics and (2) an analysis of the effects of severe weather events. These examples provide convincing evidence regarding how the dataset can be employed in multiple research fields and applications, including ocean–bay interactions, water exchange between basins, longwave and shortwave propagation along creek systems, and energy extraction of tidal waves. Therefore, this hybrid dataset may be of significant interest for stakeholders and scientists from different sectors (water engineering, ecology, urban development, energy, etc.) working on the environmental management of the Gulf of Cádiz and other tidally dominated shallow bays. It can also serve as a benchmark test for numerical hydrodynamic models, infrastructure intervention assessments (e.g., dikes or breakwaters), or renewable energy conversion system models. The dataset is available at https://doi.org/10.5281/zenodo.7484186 (Zarzuelo et al., 2022b).

Monitoring of Tidal Variation and Temperature Change-Induced Movements of an Immersed Tunnel Using Distributed Optical Fiber Sensors (DOFSs)

The short-term deformation behavior of immersed tunnels due to daily or monthly temperature changes and tidal variations is often not monitored but forms important input for a structural health assessment of the tunnel. In this study, distributed optical fiber sensors (DOFSs) are used to monitor the short-term (daily and monthly) deformation behavior of an immersed tunnel. Joint opening and the relative settlement differences between tunnel elements are monitored simultaneously at subhour intervals. Measurements show that the variation in the joint opening is strongly correlated with temperature change, and the joint gap has a tendency to open at low temperatures and to close at increasing temperatures. Simultaneously, the entire immersed section behaves more like a rigid body and moves upwards and downwards periodically due to tidal fluctuations in the river, with an observed vertical movement of slightly less than one millimeter. The tide also causes local tilting of tunnel segments, and this tilting behavior differs between winter and summer, which implies that the (seasonal) temperature-induced joint deformations affect the robustness of the tunnel to tidal loads. A soil-tunnel structure interaction analysis reveals that the cyclic vertical movement of the tunnel is driven by retardation of the tidal wave in deeper soil layers, which can be captured by a coupled flow model. This study provides new insights into the short-term deformation behavior of immersed tunnels.

Assessing the Impact of Tidal Waves on Learners’ Education of Residents of Some Coastal Communities in the Western Region of Ghana

Assessing the Impact of Tidal Waves on Learners’ Education of Residents of Some Coastal Communities in the Western Region of Ghana

Marine energy converters: Potential acoustic effects on fishes and aquatic invertebrates.

The potential effects of underwater anthropogenic sound and substrate vibration from offshore renewable energy development on the behavior, fitness, and health of aquatic animals is a continuing concern with increased deployments and installation of these devices. Initial focus of related studies concerned offshore wind. However, over the past decade, marine energy devices, such as a tidal turbines and wave energy converters, have begun to emerge as additional, scalable renewable energy sources. Because marine energy converters (MECs) are not as well-known as other anthropogenic sources of potential disturbance, their general function and what is known about the sounds and substrate vibrations that they produce are introduced. While most previous studies focused on MECs and marine mammals, this paper considers the potential of MECs to cause acoustic disturbances affecting nearshore and tidal fishes and invertebrates. In particular, the focus is on particle motion and substrate vibration from MECs because these effects are the most likely to be detected by these animals. Finally, an analysis of major data gaps in understanding the acoustics of MECs and their potential impacts on fishes and aquatic invertebrates and recommendations for research needed over the next several years to improve understanding of these potential impacts are provided.

Internal Waves in the Region of the Akselsundet Strait of Western Spitsbergen Island

Moored measurements of temperature, salinity, and currents at three moorings that operated for a year in the area of strong tidal currents in the area of the Akselsundet Strait at the mouth of the Van Mayen fiord on Western Svalbard Island are analyzed. Tidal currents flowing around an underwater sill in the strait generate intense tidal internal waves. Forced internal waves exist above the underwater slope. Vertical displacements of water particles reach 20 m. Waves rapidly decay as they propagate away from the strait and slope. They are no longer recorded as far as 12 km from the strait. Tidal currents in the strait reach a speed of 3 m/s and form an intense jet when flowing out of the strait. A strong jet of currents during spring tides presses the instruments on moorings to the bottom.

The impact of buildup proposed barrage on tidal hydrodynamics in the Shatt Al-Arab ‎River, South of Iraq

The influence of the suggested regulator barrage of the Shatt Al-Arab river on water level ‎fluctuations was tested by using a one-dimensional model. The numerical model period ‎covered six months in 2017. The performance of the model was evaluated by comparing ‎the estimated water level at two locations, Sihan, and Abu Flous. A good fit between the ‎observed and simulated water levels at the two locations was achieved with root mean ‎square error at 0.13 and 0.06 m, respectively. The model results showed that there is an ‎increase in high water levels near areas located below the barrage in both the spring and ‎neap tidal phases. The increasing of water level below the barrage could be attributed to ‎behave the river as a convergent tidal channel that characterizes by the increasing water ‎level as tidal wave propagated further toward inland areas. The highest increase in the ‎water level reaches about 0.4 m below the barrage. Additionally, the tidal range also ‎increased along the river course. The maximum increase in tidal range reaches about 0.9 m ‎below the barrage. The results obtained could be useful for a general assessment of the ‎hydrodynamic of the Shatt Al- Arab river and could give a general view in the case of the ‎construction of such a barrage to tackle the salinity intrusion problem in this river.

Dynamical Study of Coupled Riemann Wave Equation Involving Conformable, Beta, and M-Truncated Derivatives via Two Efficient Analytical Methods

In this study, the Jacobi elliptic function method (JEFM) and modified auxiliary equation method (MAEM) are used to investigate the solitary wave solutions of the nonlinear coupled Riemann wave (RW) equation. Nonlinear coupled partial differential equations (NLPDEs) can be transformed into a collection of algebraic equations by utilising a travelling wave transformation. This study’s objective is to learn more about the non-linear coupled RW equation, which accounts for tidal waves, tsunamis, and static uniform media. The variance in the governing model’s travelling wave behavior is investigated using the conformable, beta, and M-truncated derivatives (M-TD). The aforementioned methods can be used to derive solitary wave solutions for trigonometric, hyperbolic, and jacobi functions. We may produce periodic solutions, bell-form soliton, anti-bell-shape soliton, M-shaped, and W-shaped solitons by altering specific parameter values. The mathematical form of each pair of travelling wave solutions is symmetric. Lastly, in order to emphasise the impact of conformable, beta, and M-TD on the behaviour and symmetric solutions for the presented problem, the 2D and 3D representations of the analytical soliton solutions can be produced using Mathematica 10.

Investigate air turbines performance for power generation by tidal waves in the river: A review

The phenomenon of climate change resulting from the increase of global warming has become one of the main problems facing the world. Where researchers and specialists have worked for many years to find a solution that reduces this phenomenon and limits its risks. Clean energy is likely an alternative to fossil fuel sources, which are the main source of global warming. One of the clean energy sources is ocean wave energy, which is a huge and untapped energy source, despite the possibility of extracting large amounts of energy from waves. This paper focuses on the study of deep-sea turbines and their results. A study was conducted on the capture chamber. The turbines are driven and generate electricity by using a wave energy harvesting system (oscillating water column). Reaction turbines (impulse and Wells turbines) are tested and evaluated for performance in an oscillating water column system. Reaction turbines have a narrow operating range, and higher peak efficiencies. In contrast, turbines that have a greater operating range and lower peak efficiency are impulse turbines. Wells stator turbine has the highest efficiency while a variable pitch axial impulse turbine has the widest operating range. Better efficiency possessed by turbines with optimized geometry than other turbines.

Preliminary study on Strait of Malacca Tide Wave Characteristic from AIS Data Mining

In this study, advanced data mining techniques and Automatic Identification System (AIS) data were used to examine the tidal and wave dynamics of the Strait of Malacca. This strait has been an important commercial route for centuries, connecting the Indian Ocean to the South China Sea and the Pacific Ocean. It is located between Sumatra Island's east coast and Peninsular Malaysia's west coast, with the Strait of Singapore at its southeast end. The study's initial findings indicate a strong correlation between the distance of ships' coordinates and the timing of the tide, which is mainly influenced by the harmonic motion of the sun and the moon. Through AIS data mining and analysis, this study demonstrates the potential for predicting sea heights during tidal events. These results could be further explored in future research. Overall, this study offers valuable insights into the intricate tidal and wave dynamics of the world's longest strait and highlights the promise of AIS data mining for advancing our knowledge of oceanic phenomena. The research outcomes could potentially facilitate the development of more precise and effective methods for forecasting sea heights and predicting other marine processes.

Satellite-based shoreline detection along high-energy macrotidal coasts and influence of beach state

Earth observation coupled with novel image analysis techniques now present a unique and powerful tool for the historical study of shoreline change at local to global scale. However, satellite-derived shoreline (SDS) data is limited in certain areas and is associated with large uncertainties relating to environmental factors, tidal range, and wave action. We use 14 years of monthly topographic surveys at two macrotidal sites in the UK representing end members of beach type (reflective, dissipative) to investigate the influence of tidal elevation and wave action on SDS accuracy. We find that applying appropriate water level corrections can significantly improve SDS accuracy. Results show that a different approach is required for water level definition depending on beach type and reveal that ultimately SDS accuracy is primarily controlled by beach state (beach profile shape). Accounting for tidal elevation led to substantial accuracy improvement at both sites and formed the optimal SDS strategy for the reflective site (Slapton). At the dissipative site (Perranporth) considering wave-induced water level fluctuations (wave setup and/or runup), including wave shoaling, was critical for reducing the tidally corrected SDS RMSE by a third and the mean bias by three quarters. An important realization for areas with high cloud cover such as the UK, and/or low satellite coverage, was that critically low image availability restricts temporally the type of phenomenon that can be detected (e.g., seasonal/interannual variability) and may compromise computed long-term trends. Our results suggest that the optimal approach is site-specific and depends on the shoreline translation method used and is therefore different depending on the application. We propose optimal SDS strategies to increase confidence in SDS extraction in meso-macrotidal environments with potentially low satellite useability (i.e., high cloud cover and/or low satellite coverage) depending on the spatial scale of the intended application. Long-term trends derived using this approach can reproduce trends from ground-based surveys and therefore enable more accurate projections of future shoreline position to be made.

Hydro-morphodynamic modelling of mangroves imposed by tidal waves using finite element discontinuous Galerkin method

Hydro-morphodynamic modelling of mangroves imposed by tidal waves using finite element discontinuous Galerkin method

How and what turbulent are deep Mariana Trench waters?

To study potentially turbulent water motions near the deepest point on Earth in the Challenger Deep of the Mariana Trench, a 588-m long string equipped with specially designed sensitive temperature sensors was moored for nearly three years. Detailed analysis of one year of good data distinguishes ubiquitous internal tidal waves and hundreds of meters slanted convection turbulent spurs due to internal waves’ breaking from above. The spurs, or intrusions of anomalous waters, can occur on a tidal periodicity. Some tidal wave breaking including 100-m tall turbulent overturns reaching the trench floor is associated with warm waters that push from above, and of which the largest occurred during the passing of a tropical storm. The various turbulence types prevent the hadal, below 6000 m, waters from being stagnant, which is an important necessity for deep-trench life.

Morphological Dynamics on Tidal Inlet System by Generating Variability of Tidal-Wave Energy Regimes; A Process-Based Model Approach of Tide Dominated Case and Mixed Tide Dominated Case

A process-based approach of 2D morphodynamic modeling is an alternative technique to investigate the morphological evolution in the long-term period. In the conceptual model application, there is two methodologies of morphodynamic model; realistic-based model (short time scale model in days/months) and realistic-analogue model which is called process-based model (long time scale model in ~100 years). Realistic-based model is the representative of generating force with complexity of real condition model in the field, however process-based model is the simplification of forcing model by representing the major factor. In this study, the domain model is as the adaptation of Dutch Wadden Zee tidal inlet system. A couple model technique of Flow module (Delft3d) and Wave module (X-Beach) is implemented into the model system. The tidal forcing is based on one main harmonic tidal component of M2 and super harmonic tidal component of M4 and M6 from the analysis harmonic of ZUNO model. The wave forcing is 1.4 m and 330 deg as the representative wave climate condition in Wadden Zee. A process-based model shows that initially the morphological response leading into establish-state condition. Tidal wave propagation which leads to stronger cross-shore ebb-flow perpendicular to the coastline contributes in morphological evolution inside the basin and forming the outer part of the inlet (ebb-tidal delta). Wave induce current in mixed-tide energy case are as the major contribution of stirring up sediments from the sea bed, leads to transport sediment because of longshore currents process, undertow, mass transport.