Wave Effects on the Storm Surge Simulation: A Case Study of Typhoon Khanun

To study wave effects on storm surge, a depth-averaged 2D numerical model based on the Delft3D-FLOW model was utilized to simulate near-shore hydrodynamic responses to Typhoon Khanun. The Delft3D-WAVE model is coupled dynamically with the FLOW model and the enhanced vertical mixing, mass flux and wave set-up were considered as wave-current interaction in the coupled model. After verifying storm surge wind and pressure formulae of storm surge and optimizing calibration parameters, three numerical tests with different control variables were conducted. Model tests show that wave effects must be considered in numerical simulation. Simulating the flow-wave coupled model showed that wave-induced surge height could be as large as 0.4 m in near-shore areas for Typhoon Khanun. Comparing to its contribution to the peak surge height, wave-induced surge plays a more significant role to total surge height with respect to the time-averaged surge height in storm events. Wave-induced surge (wave setup) is in advance of typhoon propagation and becomes significant even before the typhoon landfall. Model tests demonstrate that the wave effects are driven predominantly by the storm wave, while the boundary wave contribution is rather limited.

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WAVE EFFECTS ON STORM SURGE IN A SMALL TWO-INLET BAY

Coastal Engineering Proceedings ◽

10.9753/icce.v36v.waves.30 ◽

2020 ◽

pp. 30

Author(s):

Mara M.Orescanin ◽

Thomas Chris Massey ◽

Matt Reffitt ◽

Britt Raubenheimer ◽

Steve Elgar

Keyword(s):

Tropical Cyclones ◽

Storm Surge ◽

Flow Model ◽

Coupled Model ◽

Coastal Flooding ◽

Wave Flow ◽

Major Contributor ◽

Tidal Inlets ◽

Hurricane Irene ◽

Wave Effects

Storm surge resulting from oceanic extreme events, commonly tropical cyclones, is a major contributor to coastal flooding and property damage. Thus, there is significant investment in accurate predictions. However, forecasts of storm surge often are focused on regional scales, and are unable to resolve complex nearshore bathymetry and small tidal inlets (Yin et al. 2016) that can be critical to local surge magnitudes and timing. Here, model simulations with a regional wave-flow coupled model (NACCS), a high bathymetric resolution uncoupled flow model (ADCIRC), and a high resolution coupled model (CSTORM) are compared with observations of storm surge during Hurricane Irene (Atlantic Storm 09, 2011) within Katama Bay, Martha's Vineyard, Massachusetts.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/hKdA2zYWI2Y

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Model Tests of a Spar-Type Floating Wind Turbine Under Wind/Wave Loads

Volume 9: Ocean Renewable Energy ◽

10.1115/omae2015-41391 ◽

2015 ◽

Cited By ~ 1

Author(s):

Fei Duan ◽

Zhiqiang Hu ◽

Jin Wang

Keyword(s):

Wind Turbine ◽

Model Test ◽

Wind Wave ◽

Wave Model ◽

Offshore Structures ◽

Model Tests ◽

Wave Loads ◽

Scaled Model ◽

Floating Wind Turbine ◽

Wave Effects

Wind power has great potential because of its clean and renewable production compared to the traditional power. Most of the present researches for floating wind turbine rely on the hydro-aero-elastic-servo simulation codes and have not been exhaustively validated yet. Thus, model tests are needed and make sense for its high credibility to master the kinetic characters of floating offshore structures. The characters of kinetic responses of the spar-type wind turbine are investigated through model test research technique. This paper describes the methodology for wind/wave model test that carried out at Deepwater Offshore Basin in Shanghai Jiao Tong University at a scale of 1:50. A Spar-type floater was selected to support the wind turbine in this test and the model blade was geometrically scaled down from the original NREL 5 MW reference wind turbine blade. The detail of the scaled model of wind turbine and the floating supporter, the test set-up configuration, the mooring system, the high-quality wind generator that can create required homogeneous and low turbulence wind, and the instrumentations to capture loads, accelerations and 6 DOF motions are described in detail, respectively. The isolated wind/wave effects and the integrated wind-wave effects on the floating wind turbine are analyzed, according to the test results.

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Coastal flooding: impact of waves on storm surge during extremes – a case study for the German Bight

Natural Hazards and Earth System Science ◽

10.5194/nhess-16-2373-2016 ◽

2016 ◽

Vol 16 (11) ◽

pp. 2373-2389 ◽

Cited By ~ 19

Author(s):

Joanna Staneva ◽

Kathrin Wahle ◽

Wolfgang Koch ◽

Arno Behrens ◽

Luciana Fenoglio-Marc ◽

...

Keyword(s):

Sea Level ◽

German Bight ◽

Wind Waves ◽

Three Dimensional ◽

Coupled Model ◽

Circulation Model ◽

Coastal Flooding ◽

Storm Events ◽

Extreme Storm ◽

Wave Induced

Abstract. This study addresses the impact of wind, waves, tidal forcing and baroclinicity on the sea level of the German Bight during extreme storm events. The role of wave-induced processes, tides and baroclinicity is quantified, and the results are compared with in situ measurements and satellite data. A coupled high-resolution modelling system is used to simulate wind waves, the water level and the three-dimensional hydrodynamics. The models used are the wave model WAM and the circulation model GETM. The two-way coupling is performed via the OASIS3-MCT coupler. The effects of wind waves on sea level variability are studied, accounting for wave-dependent stress, wave-breaking parameterization and wave-induced effects on vertical mixing. The analyses of the coupled model results reveal a closer match with observations than for the stand-alone circulation model, especially during the extreme storm Xaver in December 2013. The predicted surge of the coupled model is significantly enhanced during extreme storm events when considering wave–current interaction processes. This wave-dependent approach yields a contribution of more than 30 % in some coastal areas during extreme storm events. The contribution of a fully three-dimensional model compared with a two-dimensional barotropic model showed up to 20 % differences in the water level of the coastal areas of the German Bight during Xaver. The improved skill resulting from the new developments justifies further use of the coupled-wave and three-dimensional circulation models in coastal flooding predictions.

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MODELING SURGE-DEPENDENT VEGETATION EFFECTS ON HURRICANE-GENERATED WAVES

Coastal Engineering Proceedings ◽

10.9753/icce.v33.waves.67 ◽

2012 ◽

Vol 1 (33) ◽

pp. 67 ◽

Cited By ~ 1

Author(s):

Qin Chen ◽

Haihong Zhao ◽

Don Liu

Keyword(s):

Energy Dissipation ◽

Storm Surge ◽

Reduction Rate ◽

Wave Model ◽

Water Levels ◽

Marsh Vegetation ◽

Vegetation Effects ◽

Vegetation Height ◽

The Impact ◽

Surge Height

The study utilizes a coupled wave-surge-vegetation modeling system to quantify the effects of salt marsh vegetation on hurricane-generated waves. The wave model incorporates the energy dissipation model of Chen and Zhao (2012) for random waves over vegetation. The storm surge model incorporates the vegetal drag for both rigid and flexible types of vegetation. The surge and wave models with the vegetation effects are coupled, allowing the spatially and temporally varying vegetation heights, water levels and depth-averaged currents from the storm surge model to be fed into the wave model. Numerical experiments have revealed that vegetation can change the surge height and a storm surge can change the vegetation height. Both control the wave reduction rate in flooded wetlands. The impact of vegetation on hurricane-generated waves consists of indirect and direct effects. The former is caused by the changes in surge height due to vegetation. The latter comes from the direct interaction between vegetation and the oscillatory motion of surface waves. It has been found that flexible marsh vegetation deflects under the hydrodynamic force produced by a hurricane. The deflected height not only reduces the flow resistance in the surge model, but also decreases the energy dissipation caused by vegetation in the wave model. Consequently, neglecting plant flexibility may lead to overestimates of vegetation effects and exaggeration of wetland potential for flood risk reduction.

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Wave-induced mixing and transport of buoyant particles: application to the Statfjord A oil spill

Ocean Science ◽

10.5194/os-10-977-2014 ◽

2014 ◽

Vol 10 (6) ◽

pp. 977-991 ◽

Cited By ~ 18

Author(s):

M. Drivdal ◽

G. Broström ◽

K. H. Christensen

Keyword(s):

Oil Spill ◽

Wave Spectrum ◽

Wave Model ◽

Stokes Drift ◽

Ocean Turbulence ◽

Wave Effects ◽

Ekman Theory ◽

Energy And Momentum ◽

Drift Models ◽

Wave Induced

Abstract. This study focuses on how wave–current and wave–turbulence interactions modify the transport of buoyant particles in the ocean. Here the particles can represent oil droplets, plastic particles, or plankton such as fish eggs and larvae. Using the General Ocean Turbulence Model (GOTM), modified to take surface wave effects into account, we investigate how the increased mixing by wave breaking and Stokes shear production, as well as the stronger veering by the Coriolis–Stokes force, affects the drift of the particles. The energy and momentum fluxes, as well as the Stokes drift, depend on the directional wave spectrum obtained from a wave model. As a first test, the depth and velocity scales from the model are compared with analytical solutions based on a constant eddy viscosity (i.e., classical Ekman theory). Secondly, the model is applied to a case in which we investigate the oil drift after an oil spill off the west coast of Norway in 2007. During this accident the average net drift of oil was observed to be both slower and more deflected away from the wind direction than predicted by oil-drift models. In this case, using wind and wave forcing from the ERA Interim archive it is shown that the wave effects are important for the resultant drift and have the potential to improve drift forecasting.

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An atmosphere-wave regional coupled model: improving predictions of wave heights and surface winds in the Southern North Sea

10.5194/os-2016-51 ◽

2016 ◽

Cited By ~ 1

Author(s):

Kathrin Wahle ◽

Joanna Staneva ◽

Wolfgang Koch ◽

Luciana Fenoglio-Marc ◽

Ha T. M. Ho-Hagemann ◽

...

Keyword(s):

North Sea ◽

German Bight ◽

Surface Wind ◽

Model Performance ◽

Coupled Model ◽

Wave Model ◽

Induced Drag ◽

Wave Heights ◽

Wave Induced ◽

The Impact

Abstract. Reduction of wave forecasting errors is a challenge especially in dynamically complicated coastal ocean areas as the southern part of the North Sea area – the German Bight. Coupling of different models is a favoured approach to address this issue as it accounts for the complex interactions of waves, currents and the atmosphere. Here we study the effects of coupling between an atmospheric model and a wind wave model, which in the present study is enabled through an introduction of wave induced drag in the atmosphere model. This, on one side, leads to a reduction of the surface wind speeds, and on the other side, to a reduction of simulated wave heights. The sensitivity of atmospheric parameters such as wind speed, and atmospheric pressure to wave-induced drag, in particular under storm conditions, is studied. Additionally, the impact of the two-way coupling on wave model performance is investigated. The performance of the coupled model system has been demonstrated for extreme events and calm conditions. The results revealed that the effect of coupling results in significant changes in both wind and waves. The simulations are compared to data from in-situ and satellite observations. The results indicate that the two-way coupling improves the agreement between observations and simulations for both wind and wave parameters in comparison to the one-way coupled model. In addition, the errors of the high-resolution German Bight wave model compared to the observations have been significantly reduced in the coupled model. The improved skills resulting from the proposed method justifies its implementations for both operational and climate simulations.

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Storm surge and wave simulations in the Gulf of Mexico using a consistent drag relation for atmospheric and storm surge models

Natural Hazards and Earth System Science ◽

10.5194/nhess-12-2399-2012 ◽

2012 ◽

Vol 12 (7) ◽

pp. 2399-2410 ◽

Cited By ~ 14

Author(s):

D. Vatvani ◽

N. C. Zweers ◽

M. van Ormondt ◽

A. J. Smale ◽

H. de Vries ◽

...

Keyword(s):

Wind Speed ◽

Gulf Of Mexico ◽

Drag Coefficient ◽

Storm Surge ◽

Weather Prediction ◽

Surface Wind ◽

Wave Model ◽

Water Levels ◽

Observation Data ◽

Wave Effects

Abstract. To simulate winds and water levels, numerical weather prediction (NWP) and storm surge models generally use the traditional bulk relation for wind stress, which is characterized by a wind drag coefficient. A still commonly used drag coefficient in those models, some of them were developed in the past, is based on a relation, according to which the magnitude of the coefficient is either constant or increases monotonically with increasing surface wind speed (Bender, 2007; Kim et al., 2008; Kohno and Higaki, 2006). The NWP and surge models are often tuned independently from each other in order to obtain good results. Observations have indicated that the magnitude of the drag coefficient levels off at a wind speed of about 30 m s−1, and then decreases with further increase of the wind speed. Above a wind speed of approximately 30 m s−1, the stress above the air-sea interface starts to saturate. To represent the reducing and levelling off of the drag coefficient, the original Charnock drag formulation has been extended with a correction term. In line with the above, the Delft3D storm surge model is tested using both Charnock's and improved Makin's wind drag parameterization to evaluate the improvements on the storm surge model results, with and without inclusion of the wave effects. The effect of waves on storm surge is included by simultaneously simulating waves with the SWAN model on identical model grids in a coupled mode. However, the results presented here will focus on the storm surge results that include the wave effects. The runs were carried out in the Gulf of Mexico for Katrina and Ivan hurricane events. The storm surge model was initially forced with H*wind data (Powell et al., 2010) to test the effect of the Makin's wind drag parameterization on the storm surge model separately. The computed wind, water levels and waves are subsequently compared with observation data. Based on the good results obtained, we conclude that, for a good reproduction of the storm surges under hurricane conditions, Makin's new drag parameterization is favourable above the traditional Charnock relation. Furthermore, we are encouraged by these results to continue the studies and establish the effect of improved Makin's wind drag parameterization in the wave model. The results from this study will be used to evaluate the relevance of extending the present towards implementation of a similar wind drag parameterization in the SWAN wave model, in line with our aim to apply a consistent wind drag formulation throughout the entire storm surge modelling approach.

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Toward a coupled model to investigate wave-sea ice interactions in the Arctic marginal ice zone

10.5194/tc-2019-92 ◽

2019 ◽

Cited By ~ 1

Author(s):

Guillaume Boutin ◽

Camille Lique ◽

Fabrice Ardhuin ◽

Clément Rousset ◽

Claude Talandier ◽

...

Keyword(s):

Sea Ice ◽

Wave Attenuation ◽

Coupled Model ◽

Wave Model ◽

The Arctic ◽

Strong Interactions ◽

Short Time Scale ◽

Sea Ice Concentration ◽

Marginal Ice Zone ◽

Wave Induced

Abstract. The Arctic Marginal Ice Zone (MIZ), where strong interactions between sea ice, ocean and atmosphere are taking place, is expanding as the result of the on-going sea ice retreat. Yet, state-of-art models are not capturing the complexity of the varied processes occurring in the MIZ, and in particular the processes involved in the ocean-sea ice interactions. In the present study, a coupled sea ice - wave model is developed, in order to improve our understanding and model representation of those interactions. The coupling allows us to account for the wave radiative stress resulting from the wave attenuation by sea ice, and the sea ice lateral melt resulting from the wave-induced sea ice break-up. We found that, locally in the MIZ, the waves can affect the sea ice drift and melt, resulting in significant changes in sea ice concentration and thickness as well as sea surface temperature and salinity. Our results highlight the need to include the wave-sea ice processes in models aiming at forecasting sea ice conditions on short time scale, although the coupling between waves and sea ice would probably required to be investigated in a more complex system, allowing for interactions with the ocean and the atmosphere.

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STORM SURGE SIMULATIONS INCLUDING WAVE-CURRENT INTERACTIONS BASED ON THE 3D NEARSHORE CURRENT MODEL

Coastal Engineering Proceedings ◽

10.9753/icce.v36.waves.85 ◽

2018 ◽

pp. 85

Author(s):

Hwusub Chun ◽

Kyungmo Ahn ◽

Witold Cieslikiewicz

Keyword(s):

Storm Surge ◽

Current Model ◽

Storm Surges ◽

Wave Model ◽

Wave Forcing ◽

Bay Area ◽

The North ◽

The Republic ◽

Wave Induced ◽

The Waves

This paper presents the numerical simulation of storm surges including wave-current interactions based on the 3D nearshore current model. Newly developed numerical model included new terms on surface stress and wave-induced Reynolds stress. The present nearshore current model calculates nearshore current field under storm surge, the wave forcing terms should be provided by the additional computation on the waves and surface roller. For the wave-current interactions, the present model is dynamically coupled with wind wave model which is modified WAM applicable to shallow water. We conducted storm surge simulations in Youngil-bay located in the east coast of the Republic of Korea. One of the purpose of this simulation is to estimate the influence of large breakwater constructed in the north side of bay entrance on the erosion of beaches located inside bay area during the storm.

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Wave Modelling for Potential Wave Energy Sites Around the Outer Hebrides

Volume 8: Ocean Renewable Energy ◽

10.1115/omae2013-11356 ◽

2013 ◽

Author(s):

Charles E. Greenwood ◽

Vengatesan Venugopal ◽

David Christie ◽

James Morrison ◽

Arne Vögler

Keyword(s):

Wave Energy ◽

Energy Resource ◽

Wave Model ◽

Storm Events ◽

Wave Modelling ◽

Calibration Process ◽

Potential Wave ◽

Current Profiler ◽

Outer Hebrides ◽

Near Shore

This paper presents the results of a numerical wave modelling study carried out to assess the near shore wave energy resource around potential wave energy sites at the Outer Hebrides in the United Kingdom. This study uses Danish Hydraulic Institute’s MIKE 21 Spectral Wave model suite. Input boundary conditions are obtained from a Datawell directional wave buoy located approximately 16 km off the coast of Lewis in 60 metre depth. Additional data collected from a submerged Acoustic Wave and Current profiler (AWAC) located at 13 metre depth offshore at one of the wave energy development sites was used to calibrate and validate the wave model for separate time periods. The calibration process allows the manipulation of white capping, bottom friction and wave breaking parameters to alter the energy dissipation across the model domain. The altered parameters gave a significantly better agreement between modelled and measured results than the model defaults. While the average wave conditions provided a relatively straightforward calibration process the more extreme storm events significantly under predicted the wave height. After several trials in altering model coefficients a good agreement was reached between the model results and the AWAC data. These new sets of calibration parameters enable the simulation of wave heights within 13% for the AWAC data and marginally more for wave periods for the first 6 months of 2012.

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