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| 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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| Marié, Louis; Collard, Fabrice; Nouguier, Frederic; Pineau-guillou, Lucia; Hauser, Danièle; Boy, François; Méric, Stéphane; Sutherland, Peter; Peureux, Charles; Monnier, Goulven; Chapron, Bertrand; Martin, Adrien; Dubois, Pierre; Donlon, Craig; Casal, Tania; Ardhuin, Fabrice. |
| Surface currents are poorly known over most of the world's oceans. Satellite-borne Doppler wave and current scatterometers (DWaCSs) are among the proposed techniques to fill this observation gap. The Sea surface KInematics Multiscale (SKIM) proposal is the first satellite concept built on a DWaCS design at near-nadir angles and was demonstrated to be technically feasible as part of the European Space Agency Earth Explorer program. This article describes preliminary results from a field experiment performed in November 2018 off the French Atlantic coast, with sea states representative of the open ocean and a well-known tide-dominated current regime, as part of the detailed design and feasibility studies for SKIM. This experiment comprised airborne... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00658/77056/78354.pdf |
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| Aouf, L; Hauser, D; Chapron, Bertrand; Toffoli, A; Tourrain, C; Peureux, Charles. |
| In spite of continuous improvements of ocean wave models in the last decades, large errors still remain in particular under strongly forced conditions, often encountered in the Southern Ocean, where strong westerly winds generate some of the fiercest waves on Earth in almost unlimited fetch conditions. The newly launched China‐France Oceanography SATellite (CFOSAT) provides directional spectra of ocean waves for both wind seas and swells. Compared to Synthetic Aperture Radar (SAR), it can resolve shorter wavelengths in all directions, which dominate in non‐fully developed wind waves. Here, the assimilation of these CFOSAT wave number components is proved to bring more accurate predictions of wave growth compared to the assimilation of significant wave... |
| Tipo: Text |
Palavras-chave: Assimilation; Directional; Southern Ocean; SWH; Wave age; Wave number. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00668/77996/83370.pdf |
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| Peureux, Charles; Benetazzo, Alvise; Ardhuin, Fabrice. |
| The directional distribution of the energy of young waves is bimodal for frequencies above twice the peak frequency, and that distribution can be obscured by the presence of bound waves. Here we analyze in detail a typical case measured with a peak frequency fp = 0.18 Hz and a wind speed of 10.7 m s−1. The directional distribution for a given wavenumber is nearly symmetric, with the separation of two peaks of the directional distribution growing with frequency, reaching a separation of 150° at 35 times the peak wave number kp, with a separation that increases for wavenumbers up to 45 kp. When considering only free waves, the lobe ratio of peak energy density to the minimum energy level, in the wind direction, increases linearly with the non-dimensional... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00416/52778/53657.pdf |
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| Peureux, Charles; Ardhuin, Fabrice. |
| The ocean bottom pressure records from eight stations of the Cascadia array are used to investigate the properties of short surface gravity waves with frequencies ranging from 0.2 to 5 Hz. It is found that the pressure spectrum at all sites is a well-defined function of the wind speed U10 and frequency f, with only a minor shift of a few dB from one site to another that can be attributed to variations in bottom properties. This observation can be combined with the theoretical prediction that the ocean bottom pressure spectrum is proportional to the surface gravity wave spectrum E(f) squared, times the overlap integral I(f) which is given by the directional wave spectrum at each frequency. This combination, using E(f) estimated from modeled spectra or... |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00333/44377/43990.pdf |
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| Peureux, Charles; Ardhuin, Fabrice; Guimarães, Pedro Veras. |
| The wave action equation provides a general framework that has been applied to the conservative hydrodynamic interactions between short and long surface waves. So far, only a limited range of solutions have been investigated. Here we show that the wave action equation predicts that groups of short waves propagating over long monochromatic waves are unstable. We demonstrate theoretically and numerically a new ratchet‐type instability that progressively condenses short wave action around the long wave crests due to the correlation of phase speed and action fluctuations. This instability is of particular interest because it may lead to a higher probability of breaking for short waves propagating in directions within ±35 degrees of the dominant waves... |
| Tipo: Text |
Palavras-chave: Instability; Modulation; Wind waves. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00661/77318/83369.pdf |
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| Ardhuin, Fabrice; Brandt, Peter; Gaultier, Lucile; Donlon, Craig; Battaglia, Alessandro; Boy, François; Casal, Tania; Chapron, Bertrand; Collard, Fabrice; Cravatte, Sophie; Delouis, Jean Marc; De Witte, Erik; Dibarboure, Gerald; Engen, Geir; Johnsen, Harald; Lique, Camille; Lopez-dekker, Paco; Maes, Christophe; Martin, Adrien; Marié, Louis; Menemenlis, Dimitris; Nouguier, Frederic; Peureux, Charles; Rampal, Pierre; Ressler, Gerhard; Rio, Marie-helene; Rommen, Bjorn; Shutler, Jamie D.; Suess, Martin; Tsamados, Michel; Ubelmann, Clement; Van Sebille, Erik; Van Den Oever, Martin; Stammer, Detlef. |
| The Sea surface KInematics Multiscale monitoring (SKIM) satellite mission is designed to explore ocean surface current and waves. This includes tropical currents, notably the poorly known patterns of divergence and their impact on the ocean heat budget, and monitoring of the emerging Arctic up to 82.5°N. SKIM will also make unprecedented direct measurements of strong currents, from boundary currents to the Antarctic circumpolar current, and their interaction with ocean waves with expected impacts on air-sea fluxes and extreme waves. For the first time, SKIM will directly measure the ocean surface current vector from space. The main instrument on SKIM is a Ka-band conically scanning, multi-beam Doppler radar altimeter/wave scatterometer that includes a... |
| Tipo: Text |
Palavras-chave: Ocean current; Tropics; Arctic; Doppler; Altimetry; Sea state; Remote sensing; Ocean waves. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00498/60964/64372.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... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00410/52141/52852.pdf |
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