|
|
|
| Registros recuperados: 10 | |
|
|
| Leckler, Fabien. |
| The recent parameterizations used in spectral wave models provide today interesting results in terms of forecast and hindcast of the sea states. Nevertheless, many physical phenomena present in these models are still poorly understood and therefore poorly modeled, in particular the dissipation source term due to breaking. First, the work presented in this thesis is aimed at analyzing and criticizing the existing parameterizations of the dissipation through the explicit modeling of the underlying properties of breaking. The finding of the failure of these parameterizations to reproduce the in situ and satellite observations, a new method for the observation and the analysis of breaking is proposed using stereo video systems . This method allows the... |
| Tipo: Text |
|
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00413/52479/53265.pdf |
| |
|
|
| 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 |
| |
|
|
| 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... |
| Tipo: Text |
|
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00631/74285/73895.pdf |
| |
|
|
| Renosh, Pannimpullath R.; Jourdin, Frederic; Charantonis, Anastase A.; Yala, Khalil; Rivier, Aurelie; Badran, Fouad; Thiria, Sylvie; Guillou, Nicolas; Leckler, Fabien; Gohin, Francis; Garlan, Thierry. |
| Hydro-sedimentary numerical models have been widely employed to derive suspended particulate matter (SPM) concentrations in coastal and estuarine waters. These hydro-sedimentary models are computationally and technically expensive in nature. Here we have used a computationally less-expensive, well-established methodology of self-organizing maps (SOMs) along with a hidden Markov model (HMM) to derive profiles of suspended particulate inorganic matter (SPIM). The concept of the proposed work is to benefit from all available data sets through the use of fusion methods and machine learning approaches that are able to process a growing amount of available data. This approach is applied to two different data sets entitled “Hidden” and “Observable”. The hidden... |
| Tipo: Text |
Palavras-chave: Suspended particulate inorganic matter; Self-organizing maps; Hidden Markov Model; Machine learning; English Channel; ROMS. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00415/52653/53511.pdf |
| |
|
|
| 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... |
| Tipo: Text |
Palavras-chave: Extreme wave; Wave breaking; Wave loading. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00513/62480/66803.pdf |
| |
|
|
| 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... |
| Tipo: Text |
Palavras-chave: Wave runup; Steep slopes; Rocky cliffs; Extreme values; Banneg Island. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00463/57518/59695.pdf |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| Bertin, Xavier; De Bakker, Anouk; Van Dongeren, Ap; Coco, Giovanni; Andre, Gael; Ardhuin, Fabrice; Bonneton, Philippe; Bouchette, Frederic; Castelle, Bruno; Crawford, Wayne C.; Davidson, Mark; Deen, Martha; Dodet, Guillaume; Guerin, Thomas; Inch, Kris; Leckler, Fabien; Mccall, Robert; Muller, Heloise; Olabarrieta, Maitane; Roelvink, Dano; Ruessink, Gerben; Sous, Damien; Stutzmann, Eleonore; Tissier, Marion. |
| Infragravity (hereafter IG) waves are surface ocean waves with frequencies below those of wind-generated "short waves" (typically be- low 0.04 Hz). Here we focus on the most common type of IG waves, those induced by the presence of groups in incident short waves. Three related mechanisms explain their generation: (1) the development, shoaling and release of waves bound to the short-wave group envelopes (2) the modulation by these envelopes of the location where short waves break, and (3) the merging of bores (breaking wave front, resembling to a hydraulic jump) inside the surfzone. When reaching shallow water (O(1-10 m)), IG waves can transfer part of their energy back to higher frequencies, a process which is highly dependent on beach slope. On gently... |
| Tipo: Text |
Palavras-chave: Infragravity waves; Bound wave; Dissipation; Reflection; Sediment transport; Barrier breaching; Seiche; Earth hum. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00417/52876/53800.pdf |
| |
|
|
| 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 |
| |
| Registros recuperados: 10 | |
|
|
|
