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| Registros recuperados: 14 | |
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| Raillard, Nicolas; Prevosto, Marc; Pineau, H.. |
| Design optimization is crucial as offshore structures are exposed to deeper and harsher marine conditions. The structure behaviour is dependent on several joint environmental parameters (wind, wave, currents, etc.). Environmental contours are useful representations to provide multivariate design conditions. However, these contours may lead to different design points depending on the method used to compute them, and thus may be misleading to structural engineer. In this work, we propose to use a response meta-model for the inter-comparison of some state-of-the-art methods available for modelling multivariate extremes, in order to provide a straightforward methodology, focusing on the derivation of three-dimensional contours. The considered case study... |
| Tipo: Text |
Palavras-chave: Multivariate extreme value modelling; Environmental contours; POT; Joint probability distribution; Sea state; Engineering design. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00498/60948/64413.pdf |
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| Tran, Ngan; Chapron, Bertrand. |
| The authors report the first results in studying the polarization anisotropy of the microwave backscatter from nadir observations provided by Jason-1 altimeter in both Ku- and C-band. A small but clear wind direction signal for wind speeds above 6 m/s is revealed. These azimuthal variations of radar cross-section increase with increasing wind speed up to 14 m/s. The signatures then level off at higher winds. These results extend, for the first time, recent theoretical improved scattering approximation, and point some similarities between scattering and emission mechanisms at nadir. The observed directional effect can thus be interpreted as a signature of the curvature anisotropy of wind-generated short-scale waves. Sensitivities to both wind speed and sea... |
| Tipo: Text |
Palavras-chave: Altimeter; Radar cross section; Polarization; Wind direction; Sea state. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00004/11557/8150.pdf |
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| 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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| Armenteros Almanza, M.. |
| Present thesis focuses on ecology of assemblages and taxonomy of free-living marine nematodes. Most of the data are from Cienfuegos, a semi-enclosed bay in the Caribbean Sea; but, we also provided data on biodiversity from other areas in Cuban marine waters. Four main topics are included: description of biodiversity patterns, a microcosm experiment about effects of organic enrichment on assemblages, a taxonomic revision of the genus Terschellingia de Man, 1888, and the description of four new genera for science. |
| Tipo: Theses and Dissertations |
Palavras-chave: Ecology; Taxonomy; Marine water; Biodiversity; Sea state. |
| Ano: 2010 |
URL: http://hdl.handle.net/1834/5386 |
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| Thevenot, O.; Bouin, M. -n.; Ducrocq, V.; Brossier, C. Lebeaupin; Nuissier, O.; Pianezze, Joris; Duffourg, F.. |
| Sea state can influence the turbulent air–sea exchanges, especially the momentum flux, by modifying the sea-surface roughness. The high-resolution non-hydrostatic convection-permitting model MESO-NH is used here to investigate the impact of a more realistic representation of the waves on heavy precipitation during the Intense Observation Period (IOP) 16a of the first HyMeX Special Observation Period (SOP1). Several quasi-stationary mesoscale convective systems developed over the western Mediterranean region, two of them over the sea, and resulted in heavy precipitation on the French and Italian coasts on 26 October 2012. Three different bulk parametrizations are tested in this study: a reference case (NOWAV) without any wave effect, a parametrization... |
| Tipo: Text |
Palavras-chave: Air-sea exchanges; Mediterranean Sea; HyMeX; MESO-NH; Sea state; Roughness length; Turbulent fluxes; Heavy precipitation. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00285/39639/41533.pdf |
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| Ardhuin, Fabrice; Stopa, Justin; Chapron, Bertrand; Collard, Fabrice; Husson, Romain; Jensen, Robert E.; Johannessen, Johnny; Mouche, Alexis; Passaro, Marcello; Quartly, Graham D.; Swail, Val; Young, Ian. |
| Sea state information is needed for many applications, ranging from safety at sea and on the coast, for which real time data are essential, to planning and design needs for infrastructure that require long time series. The definition of the wave climate and its possible evolution requires high resolution data, and knowledge on possible drift in the observing system. Sea state is also an important climate variable that enters in air-sea fluxes parameterizations. Finally, sea state patterns can reveal the intensity of storms and associated climate patterns at large scales, and the intensity of currents at small scales. A synthesis of user requirements leads to requests for spatial resolution at kilometer scales, and estimations of trends of a few centimeters... |
| Tipo: Text |
Palavras-chave: Sea state; Waves; Altimeter; SAR; Swell; Remote sensing; Buoy; Microseisms. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00489/60090/63432.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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| Pineau-guillou, Lucia; Ardhuin, Fabrice; Bouin, Marie-noelle; Redelsperger, Jean-luc; Chapron, Bertrand; Bidlot, Jean-raymond; Quilfen, Yves. |
| Strong winds may be biased in atmospheric models. Here the ECMWF coupled wave-atmosphere model is used (1) to evaluate strong winds against observations, (2) to test how alternative wind stress parameterizations could lead to a more accurate model. For the period of storms Kaat and Lilli (23 to 27 January 2014), we compared simulated winds with in-situ – moored buoys and platforms - and satellite observations available from the North Atlantic. Five wind stress parameterizations were evaluated. The first result is that moderate simulated winds (5-20 m s-1) match with all observations. However, for strong winds (above 20 m s-1), mean differences appear, as much as -7 m s-1 at 30 m s-1. Significant differences also exist between observations, with buoys and... |
| Tipo: Text |
Palavras-chave: Air-sea exchanges; Northeast Atlantic; Winds; IFS; Sea state; Roughness length; Drag coefficient; Wind stress. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00410/52118/52826.pdf |
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| Monbet, Valérie; Ailliot, P; Prevosto, Marc. |
| The knowledge of sea state and wind conditions is of central importance for many offshore and nearshore operations. In this paper, we make a complete survey of stochastic models for sea state and wind time series. We begin with methods based on Gaussian processes, then non-parametric resampling methods for time series are introduced followed by various parametric models. We also propose an original statistical method, based on Monte Carlo goodness-of-fit tests, for model validation and comparison and this method is illustrated on an example of multivariate sea state time series. (C) 2006 Elsevier Ltd. All rights reserved. |
| Tipo: Text |
Palavras-chave: Model validation; Simulation; Nonlinear time series; Wind; Sea state. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2679.pdf |
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| Registros recuperados: 14 | |
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