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A comprehensive hydro-geomorphic study of cliff-top storm deposits on Banneg Island during winter 2013–2014 ArchiMer
Autret, Ronan; Dodet, Guillaume; Fichaut, Bernard; Suanez, Serge; David, Laurence; Leckler, Fabien; Ardhuin, Fabrice; Ammann, Jerome; Grandjean, Philippe; Allemand, Pascal; Filipot, Jean-francois.
Large clastic cliff-top storm deposits (called CTSDs) are one of the most remarkable signatures that characterizes extreme storm wave events on coastal cliffs. Hence, the study of CTSDs is of key importance for understanding and predicting the impacts of extreme storm wave events on rocky coasts or establishing proxies for storm intensity. The present study uses new data including hydrodynamic measurements in both deep and intertidal waters, and records of CTSDs displacement and deposition across Banneg Island during the stormy winter 2013–2014. Two drone-based surveys were carried out in January 2013 (pre-storms) and in April 2014 (post-storms). In addition, complementary field observations were carried out during the winter, providing a comprehensive and...
Tipo: Text Palavras-chave: Cliff-top storm deposit; Block transport; Extra-tropical cyclone; Run-up; Coastal erosion; Brittany.
Ano: 2016 URL: https://archimer.ifremer.fr/doc/00353/46411/46139.pdf
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A global wave parameter database for geophysical applications. Part 1: Wave-current-turbulence interaction parameters for the open ocean based on traditional parameterizations ArchiMer
Rascle, N; Ardhuin, Fabrice; Queffeulou, Pierre; Croize-fillon, Denis.
Ocean surface mixing and drift are influenced by the mixed layer depth, buoyancy fluxes and currents below the mixed layer. Drift and mixing are also functions of the surface Stokes drift U, volume Stokes transport T-s, a wave breaking height scale H-swg, and the flux of energy from waves to ocean turbulence Phi(oc). Here we describe a global database of these parameters, estimated from a well-validated numerical wave model, that uses traditional forms of the wave generation and dissipation parameterizations, and covers the years 2003-2007. Compared to previous studies, the present work has the advantage of being consistent with the known physical processes that regulate the wave field and the air-sea fluxes, and also consistent with a very large number of...
Tipo: Text Palavras-chave: Ocean mixing; Surface drift; Air sea fluxes; Surface gravity waves.
Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/publication-5903.pdf
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A global wave parameter database for geophysical applications. Part 2: Model validation with improved source term parameterization ArchiMer
Rascle, Nicolas; Ardhuin, Fabrice.
A multi-scale global hindcast of ocean waves is presented that covers the years 1994-2012, based on recently published parameterizations for wind sea and swell dissipation [Ardhuin, F., Rogers, E., Babanin, A., Filipot, J.-F., Magne, R., Roland, A., van der Westhuysen, A., Queffeulou, P., Lefevre, J.-M., Aouf, L., Collard, F., 2010. Semi-empirical dissipation source functions for wind-wave models: Part I. Definition, calibration and validation. J. Phys. Oceanogr. 40 (9), 1917-1941]. Results from this hindcast include traditional wave parameters, like the significant wave height and mean periods, and we particularly consider the accuracy of the results for phenomenal sea states, with significant heights above 14 m. Using unbiased winds, there is no evidence...
Tipo: Text Palavras-chave: Waves; Hindcast; Air-sea fluxes; Stokes drift; Mean square slope; Seismic noise.
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00155/26582/25477.pdf
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A note on the direct injection of turbulence by breaking waves ArchiMer
Rascle, Nicolas; Chapron, Bertrand; Ardhuin, Fabrice; Soloviev, Alexander.
We investigate the turbulence induced by wave-breaking at the ocean surface. Two recent models use a mechanism of direct depth injection of turbulent kinetic energy (TKE) by breaking waves. Those models aim to reproduce the near-surface mean and turbulent properties, in particular the TKE dissipation rates. Of critical importance are the injection depth of each breaking wave and the size distribution of those breaking waves. The models by Sullivan et al. (2007) and by Kudryavtsev et al. (2008) have very different parameterizations, and those differences are reviewed here and compared to available observations. Using realistic parameterizations in these models leads to TKE injections too shallow to compare to observations, in particular for developed seas....
Tipo: Text Palavras-chave: Surface waves; Wave breaking; Wave-induced turbulence; Vertical mixing; Mixed layer; Ekman currents.
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00155/26581/25476.pdf
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A numerical model for free infragravity waves: Definition and validation at regional and global scales ArchiMer
Ardhuin, Fabrice; Rawat, Arshad; Aucan, Jerome.
The spectral wave model WAVEWATCH III is extended from the windsea and swell band to lower frequencies, in order to represent free waves in the infragravity (IG) wave band. This extension is based on an empirical source of IG energy, which is defined along shorelines from the significant wave height and a mean period. The empirical proportionality factor is found to reproduce accurately the variations of free IG wave energy in coastal areas, where it was calibrated, and also has a good skill at global scales. In the open ocean, the model is particularly verified for frequencies in the range 5 to 14 mHz for which ocean bottom records are sensitive to the IG signal. The model captures between 30% and 80% of the variance in IG wave heights, depending on...
Tipo: Text Palavras-chave: Infragravity waves; SWOT; Spectral model.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00181/29272/28639.pdf
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A numerical model for ocean ultra-low frequency noise: Wave-generated acoustic-gravity and Rayleigh modes ArchiMer
Ardhuin, Fabrice; Lavanant, Thibaut; Obrebski, Mathias; Marie, Louis; Royer, Jean-yves; D'Eu, Jean-francois; Howe, Bruce M.; Lukas, Roger; Aucan, Jerome.
The generation of ultra-low frequency acoustic noise (0.1 to 1 Hz) by the nonlinear interaction of ocean surface gravity waves is well established. More controversial are the quantitative theories that attempt to predict the recorded noise levels and their variability. Here a single theoretical framework is used to predict the noise level associated with propagating pseudo-Rayleigh modes and evanescent acoustic-gravity modes. The latter are dominant only within 200 m from the sea surface, in shallow or deep water. At depths larger than 500 m, the comparison of a numerical noise model with hydrophone records from two open-ocean sites near Hawaii and the Kerguelen islands reveal: (a) Deep ocean acoustic noise at frequencies 0.1 to 1 Hz is consistent with the...
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Ano: 2013 URL: http://archimer.ifremer.fr/doc/00176/28748/27211.pdf
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A suitable metocean hindcast database for the design of Marine energy converters ArchiMer
Boudiere, Edwige; Maisondieu, Christophe; Ardhuin, Fabrice; Accensi, Mickael; Pineau-guillou, Lucia; Lepesqueur, Jeremy.
Resource assessment as well as characterisation of site climatologies for the design of Marine Energy Converters requires data bases allowing an accurate description of the environmental forcing, especially waves and sea-states, on a high resolution grid. As a support to its research activities related to the development of marine renewable energies, Ifremer is building a specific hindcast data set for the assessment of sea-states climatologies. The main features of this database, built running an up-to-date configuration of the WaveWatch III® wave model on an unstructured grid extending from the South of the North Sea to the Bay of Biscay are presented here. Attention is given to the parameterization and forcing as well as the specific output data sets...
Tipo: Text Palavras-chave: Directional spectra; Hindcast; WAVEWATCH III®; Marine renewable energy.
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00164/27524/25710.pdf
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A surface kinematics buoy (SKIB) for wave–current interaction studies ArchiMer
Veras Guimaraes, Pedro; Ardhuin, Fabrice; Sutherland, Peter; Accensi, Mickael; Hamon, Michel; Perignon, Yves; Thomson, Jim; Benetazzo, Alvise; Ferrant, Pierre.
Global navigation satellite systems (GNSSs) and modern motion-sensor packages allow the measurement of ocean surface waves with low-cost drifters. Drifting along or across current gradients provides unique measurements of wave–current interactions. In this study, we investigate the response of several combinations of GNSS receiver, motion-sensor package and hull design in order to define a prototype “surface kinematics buoy” (SKIB) that is particularly optimized for measuring wave–current interactions, including relatively short wave components that are important for air–sea interactions and remote-sensing applications. The comparison with existing Datawell Directional Waverider and Surface Wave Instrument Float with Tracking (SWIFT) buoys, as well as...
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Ano: 2018 URL: https://archimer.ifremer.fr/doc/00470/58136/60605.pdf
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A unified deep-to-shallow water wave-breaking probability parameterization ArchiMer
Filipot, Jean-francois; Ardhuin, Fabrice; Babanin, Alexander V..
Breaking probabilities and breaking wave height distributions (BWHDs) in deep, intermediate, and shallow water depth are compared, and a generic parameterization is proposed to represent the observed variability of breaking parameters as a function of the nondimensional water depth. In intermediate and deep water, where waves of different scales may have markedly different breaking probabilities, a BWHD as a function of wave frequency is proposed and validated with intermediate-depth and deep water observational data. The current study focuses on waves with frequencies between 0.55 and 3.45 times the peak frequency f(p). For the dominant frequency, the integration of the frequency-dependent BWHD provides a breaking probability that reproduces the known...
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Ano: 2010 URL: http://archimer.ifremer.fr/doc/00030/14098/11330.pdf
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A unified spectral parameterization for wave breaking: From the deep ocean to the surf zone ArchiMer
Filipot, Jean-francois; Ardhuin, Fabrice.
A new wave-breaking dissipation parameterization designed for phase-averaged spectral wave models is presented. It combines wave breaking basic physical quantities, namely, the breaking probability and the dissipation rate per unit area. The energy lost by waves is first explicitly calculated in physical space before being distributed over the relevant spectral components. The transition from deep to shallow water is made possible by using a dissipation rate per unit area of breaking waves that varies with the wave height, wavelength and water depth. This parameterization is implemented in the WAVEWATCH III modeling framework, which is applied to a wide range of conditions and scales, from the global ocean to the beach scale. Wave height, peak and mean...
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Ano: 2012 URL: http://archimer.ifremer.fr/doc/00079/18998/16571.pdf
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Air-Sea Turbulent Fluxes From a Wave-Following Platform During Six Experiments at Sea ArchiMer
Bourras, Denis; Cambra, Remi; Marié, Louis; Bouin, Marie-noëlle; Baggio, Lucio; Branger, Hubert; Beghoura, Houda; Reverdin, Gilles; Dewitte, Boris; Paulmier, Aurélien; Maes, Christophe; Ardhuin, Fabrice; Pairaud, Ivane; Fraunié, Philippe; Luneau, Christopher; Hauser, Danièle.
Turbulent fluxes at the air‐sea interface are estimated with data collected in 2011 to 2017 with a low‐profile platform during six experiments in four regions. The observations were carried out with moderate winds (2‐10 m s‐1) and averaged wave heights of 1.5 m. Most of the time, there was a swell, with an averaged wave age (the ratio between wave phase speed and wind speed) being equal to 2.8±1.6. Three flux calculation methods are used, namely the eddy‐covariance (EC), the inertial‐dissipation (ID), and the bulk methods. For the EC method, a spectral technique is proposed to correct wind data from platform motion. A mean bias affecting the friction velocity (u*) is then evaluated. The comparison between EC u* and ID u* estimates suggests that a constant...
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Ano: 2019 URL: https://archimer.ifremer.fr/doc/00503/61436/65156.pdf
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Analysis and Interpretation of Frequency–Wavenumber Spectra of Young Wind Waves ArchiMer
Leckler, Fabien; Ardhuin, Fabrice; Peureux, Charles; Benetazzo, Alvise; Bergamasco, Filippo; Dulov, Vladimir.
The energy level and its directional distribution are key observations for understanding the energy balance in the wind-wave spectrum between wind-wave generation, nonlinear interactions, and dissipation. Here, properties of gravity waves are investigated from a fixed platform in the Black Sea, equipped with a stereo video system that resolves waves with frequency f up to 1.4 Hz and wavelengths from 0.6 to 11 m. One representative record is analyzed, corresponding to young wind waves with a peak frequency fp = 0.33 Hz and a wind speed of 13 m s−1. These measurements allow for a separation of the linear waves from the bound second-order harmonics. These harmonics are negligible for frequencies f up to 3 times fp but account for most of the energy at higher...
Tipo: Text Palavras-chave: Circulation; Dynamics; Waves; Oceanic; Observational techniques and algorithms; Remote sensing.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00284/39524/38017.pdf
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Assessment of SARAL/AltiKa Wave Height Measurements Relative to Buoy, Jason-2, and Cryosat-2 Data ArchiMer
Hito Sepulveda, Hector; Queffeulou, Pierre; Ardhuin, Fabrice.
SARAL/AltiKa GDR-T are analyzed to assess the quality of the significant wave height (SWH) measurements. SARAL along-track SWH plots reveal cases of erroneous data, more or less isolated, not detected by the quality flags. The anomalies are often correlated with strong attenuation of the Ka-band backscatter coefficient, sensitive to clouds and rain. A quality test based on the 1Hz standard deviation is proposed to detect such anomalies. From buoy comparison, it is shown that SARAL SWH is more accurate than Jason-2, particularly at low SWH, and globally does not require any correction. Results are better with open ocean than with coastal buoys. The scatter and the number of outliers are much larger for coastal buoys. SARAL is then compared with Jason-2 and...
Tipo: Text Palavras-chave: Radar altimeter; Significant wave height; Satellite; SARAL; AltiKa; Validation.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00286/39675/38199.pdf
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Atmospheric storm surge modeling methodology along the French (Atlantic and English Channel) coast ArchiMer
Muller, Heloise; Pineau-guillou, Lucia; Idier, Deborah; Ardhuin, Fabrice.
Storm surge modeling and forecast are the key issues for coastal risk early warning systems. As a general objective, this study aims at improving high-frequency storm surge variations modeling within the PREVIMER system (www.previmer.org), along the French Atlantic and English Channel coasts. The paper focuses on (1) sea surface drag parameterization and (2) uncertainties induced by the meteorological data quality. The modeling is based on the shallow-water version of the model for applications at regional scale (MARS), with a 2-km spatial resolution. The model computes together tide and surge, allowing properly taking into account tide-surge interactions. To select the most appropriate parameterization for the study area, a sensitivity analysis on sea...
Tipo: Text Palavras-chave: Storm surge; MARS; Sea surface drag; Meteorological forcing.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00219/32982/31404.pdf
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Bilan des tempêtes de l’hiver 2013-2014 sur la dynamique de recul du trait de côte en Bretagne ArchiMer
Blaise, Emmanuel; Suanez, Serge; Stephan, Pierre; Fichaut, Bernard; David, Laurence; Cuq, Veronique; Autret, Ronan; Houron, Julien; Rouan, Mathias; Floc'H, France; Ardhuin, Fabrice; Cancouet, Romain; Davidson, Robert; Costa, Stephane; Delacourt, Christophe.
Between December 2013 and March 2014, a cluster of about 12 storm events hit the coast of Brittany with an exceptional frequency. It was in February that these storm events were the most frequent and particularly virulent. The significant wave heights measured off Finistere reached respectively 12.3 m and 12.4 m during Petra and Ulla storms on February 5 and 14. However, analysis of hydrodynamic conditions shows that only three episodes promoted extreme morphogenetic conditions because they were combined with high spring tide level. The first one occurred on January 1 to 4, it was followed by events from February 1 to 3, and March 2-3. During these three extreme events observed tide levels were above highest astronomical tide level (HAT). Maximum surge...
Tipo: Text Palavras-chave: Tempête; Érosion; Trait de côte; Marée de vive-eau; Bretagne; Surcote; Storm; High spring tide; Surge; Erosion; Shoreline; Brittany.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00310/42171/43029.pdf
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Coastal wave reflection, directional spread, and seismoacoustic noise sources ArchiMer
Ardhuin, Fabrice; Roland, Aron.
Coastal reflection is introduced in a phase-averaged numerical wave model, first with a constant coefficient, and then with a reflection coefficient defined from the shoreface slope and that depends on the incident wave height and mean frequency. This parameterization is used in both regular and unstructured grids. The calibration involves a site-specific shoreface slope that is associated with the local geomorphology of the shoreline. Using wave buoy data off Hawaii and the U.S. West Coast, it is found that coastal reflection is necessary to reproduce observed directional properties of coastal sea states. Errors on the mean directional spread are reduced by up to 30% for the frequency band 0.04 to 0.30 Hz with, at most locations, very little impact on the...
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Ano: 2012 URL: http://archimer.ifremer.fr/doc/00088/19938/17604.pdf
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Comments on "A Combined Derivation of the Integrated and Vertically Resolved, Coupled Wave-Current Equations" ArchiMer
Ardhuin, Fabrice; Suzuki, Nobuhiro; Mcwilliams, James C.; Aiki, Hidenori.
Several equivalent equations for the evolution of the wave-averaged current momentum have been proposed, implemented, and used. In contrast, the equation for the total momentum, which is the sum of the current and wave momenta, has not been widely used because it requires a less practical wave forcing. In an update on previous derivations, Mellor proposed a new formulation of the wave forcing for the total momentum equation. Here, the authors show that this derivation misses a leading-order term that has a zero depth-integrated value. Corrected for this omission, the wave forcing is equivalent to that in the first paper by Mellor. When this wave forcing effect on the currents is approximated it leads to an inconsistency. This study finally repeats and...
Tipo: Text Palavras-chave: Currents; Mixed layer; Sea state.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00406/51733/52298.pdf
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Comments on "The Depth-Dependent Current and Wave Interaction Equations: A Revision" ArchiMer
Bennis, Anne-claire; Ardhuin, Fabrice.
Equations for the wave-averaged three-dimensional momentum equations have been published in this journal. It appears that these equations are not consistent with the known depth-integrated momentum balance, especially over a sloping bottom. These equations should thus be considered with caution, because they can produce erroneous flows, particularly outside of the surf zone. It is suggested that the inconsistency in the equations may arise from the different averaging operators applied to the different terms of the momentum equation. It is concluded that other forms of the momentum equations, expressed in terms of the quasi-Eulerian velocity, are better suited for three-dimensional modeling of wave current interactions.
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Ano: 2011 URL: http://archimer.ifremer.fr/doc/00052/16297/13810.pdf
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Comparison and validation of physical wave parameterizations in spectral wave models ArchiMer
Stopa, Justin; Ardhuin, Fabrice; Babanin, Alexander; Zieger, Stefan.
Recent developments in the physical parameterizations available in spectral wave models have already been validated, but there is little information on their relative performance especially with focus on the higher order spectral moments and wave partitions. This study concentrates on documenting their strengths and limitations using satellite measurements, buoy spectra, and a comparison between the different models. It is confirmed that all models perform well in terms of significant wave heights; however higher-order moments have larger errors. The partition wave quantities perform well in terms of direction and frequency but the magnitude and directional spread typically have larger discrepancies. The high-frequency tail is examined through the mean...
Tipo: Text Palavras-chave: WAVEWATCH III; Spectral wave modeling; Wave hindcasting; Source terms; Higher order wave moments; Swell dissipation.
Ano: 2016 URL: https://archimer.ifremer.fr/doc/00280/39122/38300.pdf
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Corrigenda of ’Explicit wave-averaged primitive equations using a Generalized Lagrangian Mean’ ArchiMer
Ardhuin, Fabrice; Rascle, Nicolas; Belibassakis, K. A..
Ardhuin et al. (2008) gave a second-order approximation in the wave slope of the exact Generalized Lagrangian Mean (GLM) equations derived by Andrews and McIntyre (1978), and also performed a coordinate transformation, going from a from GLM to a ’GLMz’ set of equations. That latter step removed the wandering of the GLM mean sea level away from the Eulerian-mean sea level, making the GLMz flow non-divergent. That step contained some inaccuarate statements about the coordinate transformation, while the rest of the paper contained an error on the surface dynamic boundary condition for viscous stresses. I am thankful to Mathias Delpey and Hidenori Aiki for pointing out these errors, which are corrected below.
Tipo: Text Palavras-chave: Wave-current; GLM; Air-sea.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00380/49165/49601.pdf
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