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| Registros recuperados: 17 | |
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| Jourdin, Frederic; Tessier, Caroline; Le Hir, Pierre; Verney, Romaric; Lunven, Michel; Loyer, Sophie; Lusven, Andre; Filipot, Jean-francois; Lepesqueur, Jeremy. |
| A pair of self-contained acoustic Doppler current profilers (SC-ADCPs) operating with different frequencies were moored on a muddy sea bottom at about 20 m depth in the Bay of Vilaine off the French Atlantic coast. With their acoustic beams oriented upwards, the SC-ADCPs ensonified most of the water column. The results of several months of in situ recorded echo intensity data spanning 2 years (2003 to 2004) from the dual-frequency ADCPs are presented in this paper. The aim was to estimate suspended particle mass concentration and mean size. A concentration index CI is proposed for the estimation of particle concentration. Based on theory the CI-unlike the volume backscatter strength-does not depend on particle size. Compared with in situ optical data, the... |
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| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00213/32427/30896.pdf |
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| 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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| Filipot, Jean-francois; The Dime Group,. |
| This paper presents a eld experiment part of the DiMe project and aiming at capturing extreme sea states with a focus on their wave breaking properties. These observations collected from La Jument lighthouse, are intended to help in re ning the design conditions for Marine Renewable Energy (MRE) Converters. Preliminary analyses from the eld observations are presented, which include stereo-video, x-band radar and accelerometers data. |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00647/75873/76869.pdf |
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| Bennis, Anne-claire; Furgerot, Lucille; Bailly Du Bois, Pascal; Dumas, Franck; Odaka, Tina; Lathuilière, Cyril; Filipot, Jean-francois. |
| Modelling three-dimensional wave-current-turbulence interactions in extreme tidal environments is still challenging and necessary for the development of the tidal industry, particularly for the dimensioning of tidal converters. Following this objective, we focus our study on the most energetic tidal site in Western Europe, the Alderney Race (France). Due to the strong tidal current at this location, wave-current interactions were poorly studied by the past and often neglected. We propose to assess how they impact the Alderney Race hydrodynamic by the use of numerical modelling and in-situ measurements. In this study, the following wave-current interactions were observed: (i) Stokes drift effects inducing an increase/decrease in the current depending on the... |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00599/71155/73092.pdf |
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| Stringari, Ce; Prevosto, Marc; Filipot, Jean-francois; Leckler, Fabien; Guimaraes, Pv. |
| This paper presents a novel method for obtaining the probability wave of breaking (Pb) of deep water, dominant wind‐sea waves (that is, waves made of the energy within ±30% of the peak wave frequency) derived from Gaussian wave field theory. For a given input wave spectrum we demonstrate how it is possible to derive a joint probability density function between wave phase speed (c) and horizontal orbital velocity at wave crest (u) from which a model for Pb can be obtained. A non‐linear kinematic wave breaking criterion consistent with the Gaussian framework is further proposed. Our model would allow, therefore, for application of the classical wave breaking criterion (that is, wave breaking occurs if u/c > 1) in spectral wave models which, to the... |
| Tipo: Text |
Palavras-chave: Wave Breaking; Gaussian Field Theory; Wave Modeling. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00677/78894/81199.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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| Filipot, Jean-francois; Guimaraes, P.; Leckler, Fabien; Hortsmann, J.; Carrasco, R.; Leroy, Elodie; Fady, N.; Accensi, Mickael; Prevosto, Marc; Duarte, Rui; Roeber, V.; Benetazzo, A.; Raoult, C.; Franzetti, M.; Varing, Audrey; Le Dantec, N.. |
| This paper presents results from an experiment designed to improve the understanding of the relationship between extreme breaking waves and their mechanical loading on heritage offshore lighthouses. The experiment, conducted at La Jument, an iconic French offshore lighthouse, featured several records of wave, current and structure accelerations acquired during severe storm conditions, with individual waves as high as 24 m. Data analysis focuses on a storm event marked by a strong peak in the horizontal accelerations measured inside La Jument. Thanks to stereo-video wave measurements synchronized to the acceleration record we were able to identify and describe the breaking wave responsible for this intense loading. Our observations suggest that this giant... |
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Palavras-chave: Extreme wave; Wave breaking; Wave loading. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00513/62480/66803.pdf |
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| Guillou, Sylvain; Filipot, Jean-francois; Thiebot, Jérôme; Germain, Gregory; Chaplain, Nicolas; Ikhennicheu, Maria; Duarte, Rui; Gaurier, Benoit; Bourgoin, Adrien; Mercier, Philippe; Ata, Riadh; Laverne, Jérôme; Benhamadouche, Sofiane; Pieterse, Aline; Maisondieu, Christophe; Poizot, Emmanuel; Poirier, Jean-charles; Auvray, Cedric; Droniou, Elois; Arramounet, Valentin; Pinon, Grégory. |
| Tidal turbine will be installed in area with high current and high turbulence level. A characterisation of this last is required. The aim of the project THYMOTE is to characterize and understand the generation of eddies from smaller to several tens of meters. Three technics are used: Numerical modelling, Physical modelling, field measurements. Physical and numerical modelling show clearly the appearance of the eddies close to the bottom in presence of dunes or rocks and their motion towards the free surface. |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00479/59091/61729.pdf |
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| Dodet, Guillaume; Leckler, Fabien; Sous, D.; Ardhuin, Fabrice; Filipot, Jean-francois; Suanez, S.. |
| Wave runup is known to depend on offshore wave conditions and coastal morphology. While most field studies on wave runup have focused on low‐to‐mild‐sloping sandy beaches, runup measurements on steep and irregular rocky cliff profiles are still very scarce. Here we investigate the physical processes controlling wave runup in such environments and the range of applicability of empirical runup formula. This study focuses on the steep rocky cliffs (0.1 < tanβ < 0.4) of Banneg Island, a small island located in the Molène archipelago, Brittany, France, occasionally flooded during extreme water level events. A statistical parameter for extreme runup is derived from the measurements of pressure sensors deployed in the intertidal zone. Deep water wave... |
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Palavras-chave: Wave runup; Steep slopes; Rocky cliffs; Extreme values; Banneg Island. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00463/57518/59695.pdf |
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| 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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| Filipot, Jean-francois; Delafosse, Coline; Marzin, Thibault; Baston, Susana. |
| The present paper discusses the errors produced while estimating the tidal power with numerical circulation models. The study relies on the analysis of five model-data comparisons issued from the literature. As usually done in the tidal power assessment studies, statistics are first derived for the current velocities. The novelty of this work resides in the direct computation of power density statistics. The errors in the power density prediction are found to be significantly higher than for the current velocity, as expected since power density is a function of velocity cubed. This stresses the need to consider the uncertainties in the tidal energy estimation for the profitability assessment of potential tidal sites. |
| Tipo: Text |
Palavras-chave: Tidal power; Numerical circulation models; ADCP; Statistics. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00230/34114/32569.pdf |
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| Suanez, Serge; Cancouet, Romain; Floc'H, France; Blaise, Emmanuel; Ardhuin, Fabrice; Filipot, Jean-francois; Cariolet, Jean-marie; Delacourt, Christophe. |
| Monitoring of dune erosion and accretion on the high-energy macrotidal Vougot beach in North Brittany (France) over the past decade (2004–2014) has revealed significant morphological changes. Dune toe erosion/accretion records have been compared with extreme water level measurements, defined as the sum of (i) astronomic tide; (ii) storm surge; and (iii) vertical wave runup. Runup parameterization was conducted using swash limits, beach profiles, and hydrodynamic (Hm0, Tm0,–1, and high tide water level—HTWL) data sets obtained from high frequency field surveys. The aim was to quantify in-situ environmental conditions and dimensional swash parameters for the best calibration of Battjes [1] runup formula. In addition, an empirical equation based on observed... |
| Tipo: Text |
Palavras-chave: Macrotidal beach; Runup; Storm; Dune; Erosion; Extreme water level; NAO. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00276/38765/37306.pdf |
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| Filipot, Jean-francois; Prevosto, Marc; Maisondieu, Christophe; Le Boulluec, Marc; Thomson, Jim. |
| This work presents the analysis of wave and turbulence measurements collected at a tidal energy site. A new method is introduced to produce more consistent and rigorous estimations of the velocity fluctuations power spectral densities. An analytical function is further proposed to fit the observed spectra and could be input to the numerical models predicting power production and structural loading on tidal turbines. Another new approach is developed to correct for the effect of the Doppler noise on the high frequencies power spectral densities. The analysis of velocity time series combining wave and turbulent contributions demonstrates that the turbulent motions are coherent throughout the water column, rendering the wave coherence-based methods not... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00254/36537/35074.pdf |
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| 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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| Leckler, Fabien; Ardhuin, Fabrice; Filipot, Jean-francois; Mironov, Alexey. |
| Whitecaps are the main sink of wave energy and their occurrence has been related to the steepness of the waves. Recent parameterizations of the wave dissipation in numerical models are based on this property, but wave models have seldom been verified in terms of whitecap properties. Here we analyze and adjust the breaking statistics used in two recent wave dissipation parameterizations implemented in the spectral wave model WAVEWATCH III (R) and now used operationaly at NOAA/NCEP. For dominant breaking waves, the reduction of breaking probabilities with wave age is well reproduced. Across the spectrum, the parameterizations produce a reasonable distribution of breaking fronts for wave frequencies up to three times the dominant frequency, but fail to... |
| Tipo: Text |
Palavras-chave: Wave breaking; Dissipation source term; Whitecap statistics. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00155/26579/26386.pdf |
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| Registros recuperados: 17 | |
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