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Registros recuperados: 129 | |
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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... |
Tipo: Text |
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Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00088/19938/17604.pdf |
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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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Boutin, Guillaume; Ardhuin, Fabrice; Dumont, Dany; Sevigny, Caroline; Girard Ardhuin, Fanny; Accensi, Mickael. |
Wind waves may play an important role in the evolution of sea ice. That role is largely determined by how fast the ice layer dissipates the wave energy. The transition from a continuous layer of ice to a series of broken floes is expected to have a strong impact on the several attenuation processes. Here we explore the possible effects of basal friction, scattering, and dissipation within the ice layer. The ice is treated as a single layer that can be fractured in many floes. Dissipation associated with ice flexure is evaluated using an anelastic linear dissipation and a cubic inelastic viscous dissipation. Tests aiming to reproduce a Marginal Ice Zone are used to discuss the effects of each process separately. Attenuation is exponential for friction and... |
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Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00454/56591/58274.pdf |
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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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Dobler, Delphine; Huck, Thierry; Maes, Christophe; Grima, Nicolas; Blanke, Bruno; Martinez, Elodie; Ardhuin, Fabrice. |
In the open ocean, floating surface debris such as plastics concentrate in five main accumulation zones centered around 30° latitude, far from highly turbulent areas. Using Lagrangian advection of numerical particles by surface currents from ocean model reanalysis, previous studies have shown long-distance connection from the accumulation zones of the South Indian to the South Pacific oceans. An important physical process affecting surface particles but missing in such analyses is wave-induced Stokes drift. Taking into account surface Stokes drift from a wave model reanalysis radically changes the fate of South Indian particles. The convergence region moves from the east to the west of the basin, so particles leak to the South Atlantic rather than the... |
Tipo: Text |
Palavras-chave: Marine debris; Microplastics; Stokes drift; Indian Ocean; Lagrangian analysis; Ocean surface pathways. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00512/62320/69273.pdf |
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Gommenginger, Christine; Chapron, Bertrand; Hogg, Andy; Buckingham, Christian; Fox-kemper, Baylor; Eriksson, Leif; Soulat, Francois; Ubelmann, Clément; Ocampo-torres, Francisco; Nardelli, Bruno Buongiorno; Griffin, David; Lopez-dekker, Paco; Knudsen, Per; Andersen, Ole; Stenseng, Lars; Stapleton, Neil; Perrie, William; Violante-carvalho, Nelson; Schulz-stellenfleth, Johannes; Woolf, David; Isern-fontanet, Jordi; Ardhuin, Fabrice; Klein, Patrice; Mouche, Alexis; Pascual, Ananda; Capet, Xavier; Hauser, Daniele; Stoffelen, Ad; Morrow, Rosemary; Aouf, Lotfi; Breivik, Øyvind; Fu, Lee-lueng; Johannessen, Johnny A.; Aksenov, Yevgeny; Bricheno, Lucy; Hirschi, Joel; Martin, Adrien Ch; Martin, Adiran P; Nurser, George; Polton, Jeff; Wolf, Judith; Johnsen, Harald; Soloviev, Alexander; Jacobs, Gregg A.; Collard, Fabrice; Groom, Steve; Kudryavtsev, Vladimir; Wilkin, John; Navarro, Victor; Babanin, Alex; Martin, Matthew; Siddorn, John; Saulter, Andrew; Rippeth, Tom; Emery, Bill; Maximenko, Nikolai; Romeiser, Roland; Graber, Hans; Azcarate, Aida Alvera; Hughes, Chris W.; Vandemark, Doug; Silva, Jose Da; Leeuwen, Peter Jan Van; Naveira-garabato, Alberto; Gemmrich, Johannes; Mahadevan, Amala; Marquez, Jose; Munro, Yvonne; Doody, Sam; Burbidge, Geoff. |
High-resolution satellite images of ocean color and sea surface temperature reveal an abundance of ocean fronts, vortices and filaments at scales below 10 km but measurements of ocean surface dynamics at these scales are rare. There is increasing recognition of the role played by small scale ocean processes in ocean-atmosphere coupling, upper-ocean mixing and ocean vertical transports, with advanced numerical models and in situ observations highlighting fundamental changes in dynamics when scales reach 1 km. Numerous scientific publications highlight the global impact of small oceanic scales on marine ecosystems, operational forecasts and long-term climate projections through strong ageostrophic circulations, large vertical ocean velocities and mixed layer... |
Tipo: Text |
Palavras-chave: Satellite; Air sea interactions; Upper ocean dynamics; Submesoscale; Coastal; Marginal ice zone; Radar; Along-track interferometry. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00510/62121/66325.pdf |
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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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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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Aubourg, Quentin; Campagne, Antoine; Peureux, Charles; Ardhuin, Fabrice; Sommeria, Joel; Viboud, Samuel; Mordant, Nicolas. |
Weak-turbulence theory is a statistical framework to describe a large ensemble of nonlinearly interacting waves. The archetypal example of such system is the ocean surface that is made of interacting surface gravity waves. Here we describe a laboratory experiment dedicated to probe the statistical properties of turbulent gravity waves. We set up an isotropic state of interacting gravity waves in the Coriolis facility (13-m-diam circular wave tank) by exciting waves at 1 Hz by wedge wave makers. We implement a stereoscopic technique to obtain a measurement of the surface elevation that is resolved in both space and time. Fourier analysis shows that the laboratory spectra are systematically steeper than the theoretical predictions and the field observations... |
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Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00410/52141/52852.pdf |
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Husson, R.; Ardhuin, Fabrice; Collard, Fabrice; Chapron, Bertrand; Balanche, Abel. |
Swells radiating across ocean basins are fingerprints of the large ocean storms that generated them, which are otherwise poorly observed. Here we analyze the signature of one swell event in the seismic noise recorded all around the Pacific and we show that it is a natural complement to the global coverage provided by the Synthetic Aperture Radar wave mode data from ENVISAT. In particular the seismic stations are much more sensitive to low frequency and amplitude signals than buoys and SAR, capturing swell forerunners a couple of days before they can be detected from space or in situ data. This information helps detect in the SAR measurements the presence of very long swell, with periods of 22 s in our case example, that were otherwise excluded. Citation:... |
Tipo: Text |
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Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00092/20328/17977.pdf |
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Ardhuin, Fabrice. |
Primary microseisms are background seismic oscillations recorded everywhere on Earth with typical frequencies 0.05 < f < 0.1 Hz. They appear to be generated by ocean waves of the same frequency f, propagating over shallow bottom topography. Previous quantitative models for the generation of primary microseisms considered wave propagation over topographic features with either large scales, equivalent to a vertical point force, or small scales matching ocean wave wavelengths, equivalent to a horizontal force. While the first requires unrealistic bottom slopes to explain measured Rayleigh wave amplitudes, the second produced Love waves and not enough Rayleigh waves. Here we show how the small scales actually produce comparable horizontal and vertical... |
Tipo: Text |
Palavras-chave: Microseisms; Ocean waves; Topography; Sand waves. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00461/57240/59237.pdf |
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Boutin, Guillaume; Lique, Camille; Ardhuin, Fabrice; Rousset, Clément; Talandier, Claude; Accensi, Mickael; Girard Ardhuin, Fanny. |
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... |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00601/71283/69690.pdf |
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Holding, Thomas; Ashton, Ian; Shutler, Jamie D.; Land, Peter E.; Nightingale, Philip D.; Rees, Andrew P.; Brown, Ian; Piolle, Jean-francois; Kock, Annette; Bange, Hermann W.; Woolf, David K.; Goddijn-murphy, Lonneke; Pereira, Ryan; Paul, Frederic; Girard-ardhuin, Fanny; Chapron, Bertrand; Rehder, Gregor; Ardhuin, Fabrice; Donlon, Craig J.. |
The flow (flux) of climate-critical gases, such as carbon dioxide (CO2), between the ocean and the atmosphere is a fundamental component of our climate and an important driver of the biogeochemical systems within the oceans. Therefore, the accurate calculation of these air–sea gas fluxes is critical if we are to monitor the oceans and assess the impact that these gases are having on Earth's climate and ecosystems. FluxEngine is an open-source software toolbox that allows users to easily perform calculations of air–sea gas fluxes from model, in situ, and Earth observation data. The original development and verification of the toolbox was described in a previous publication. The toolbox has now been considerably updated to allow for its use as a Python... |
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Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00598/70983/69247.pdf |
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Guimarães, Pedro Veras; Ardhuin, Fabrice; Bergamasco, Filippo; Leckler, Fabien; Filipot, Jean-francois; Shim, Jae-seol; Dulov, Vladimir; Benetazzo, Alvise. |
Stereo imaging of the sea surface elevation provides unique field data to investigate the geometry and dynamics of oceanic waves. Typically, this technique allows retrieving the 4-D ocean topography (3-D space + time) at high frequency (up to 15–20 Hz) over a sea surface region of area ~104 m2. Stereo data fill the existing wide gap between sea surface elevation time-measurements, like the local observation provided by wave-buoys, and large-scale ocean observations by satellites. The analysis of stereo images provides a direct measurement of the wavefield without the need of any linear-wave theory assumption, so it is particularly interesting to investigate the nonlinearities of the surface, wave-current interaction, rogue waves, wave breaking, air-sea... |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00631/74285/73895.pdf |
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Ardhuin, Fabrice; Gualtieri, Lucia; Stutzmann, Eleonore. |
Microseismic activity, recorded everywhere on Earth, is largely due to ocean waves. Recent progress has clearly identified sources of microseisms in the most energetic band, with periods from 3 to 10 s. In contrast, the generation of longer-period microseisms has been strongly debated. Two mechanisms have been proposed to explain seismic wave generation: a primary mechanism, by which ocean waves propagating over bottom slopes generate seismic waves, and a secondary mechanism which relies on the nonlinear interaction of ocean waves. Here we show that the primary mechanism explains the average power, frequency distribution, and most of the variability in signals recorded by vertical seismometers, for seismic periods ranging from 13 to 300 s. The secondary... |
Tipo: Text |
Palavras-chave: Hum; Infragravity waves; Numerical model; Microseisms. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00251/36219/34769.pdf |
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Registros recuperados: 129 | |
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