Consulta: subjectFacets:"Waves"
Registros recuperados: 21
Data/hora: 07/06/2024 01:07:45

A global wave parameter database for geophysical applications. Part 2: Model validation with improved source term parameterization
Provedor de dados: 5
Autores: Rascle, Nicolas; Ardhuin, Fabrice.
A multi-scale global hindcast of ocean waves is presented that covers the years 1994-2012, based on recently published parameterizations for wind sea and swell dissipation [Ardhuin, F., Rogers, E., Babanin, A., Filipot, J.-F., Magne, R., Roland, A., van der Westhuysen, A., Queffeulou, P., Lefevre, J.-M., Aouf, L., Collard, F., 2010. Semi-empirical dissipation source functions for wind-wave models: Part I. Definition, calibration and validation. J. Phys. Oceanogr. 40 (9), 1917-1941]. Results from this hindcast include traditional wave parameters, like the significant wave height and mean periods, and we particularly consider the accuracy of the results for phenomenal sea states, with significant heights above 14 m. Using unbiased winds, there is no evidence...
Tipo: Text
Palavras-chave: Waves; Hindcast; Air-sea fluxes; Stokes drift; Mean square slope; Seismic noise.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00155/26582/25477.pdf

Modélisation des turbidités en Bretagne sud et validation par des mesures in situ
Provedor de dados: 5
Autores: Tessier, Caroline; Le Hir, Pierre; Dumas, Franck; Jourdin, F.
A hydrodynamic and sediment model of South Brittany is calibrated with ADCP measurements, which allow to estimate hydrodynamic forcing and concentration of suspended particulate matter. The exercise of comparison between observed and simulated concentrations reveals that turbidity is highly dependant on numerous strongly coupled sedimentary and physical processes.
Tipo: Text
Palavras-chave: Waves; ADCP; Acoustical backscattering; Modelisation; Turbidity; Vagues; ADCP; Rétrodiffusion acoustique; Modélisation; Turbidité.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-6300.pdf

The Vertical Structure of Large-Scale Unsteady Currents
Provedor de dados: 5
Autores: Hochet, Antoine; Colin De Verdiere, Alain; Scott, Robert.
A linear model based on the quasigeostrophic equations is constructed in order to predict the vertical structure of Rossby waves and, more broadly, of anomalies resolved by altimeter data, roughly with periods longer than 20 days and with wavelengths larger than 100 km. The subsurface field is reconstructed from sea surface height and climatological stratification. The solution is calculated in periodic rectangular regions with a 3D discrete Fourier transform. The effect of the mean flow on Rossby waves is neglected, which the authors believe is a reasonable approximation for low latitudes. The method used has been tested with an idealized double- gyre simulation [performed with the Miami Isopycnal Coordinate Ocean Model (MICOM)]. The linear model is able...
Tipo: Text
Palavras-chave: Circulation/ Dynamics; Ocean dynamics; Rossby waves; Waves; Oceanic; Mathematical and statistical techniques; Fourier analysis; Models and modeling; Quasigeostrophic models.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00260/37081/35586.pdf

Caractérisation et dynamique des turbidités en zone côtière : L'exemple de la région marine Bretagne Sud
Provedor de dados: 5
Autores: Tessier, Caroline.
The space and time turbidity variability in Southern Brittany was studied, from the combination of results of hydrological campaigns, long-term instrumented moorings, satellite observations and 3D process-based numerical modelling.  Previous observations exhibit a cross-shore concentration gradient with values hardly exceeding 30 mg/l beyond the littoral zone. Acoustic profilers (ADCP) were moored to measure currents, waves and the associated dynamics of fine particles. Time series of mass concentration in the whole water column were estimated from the analysis of the backscattered signal. During wave episodes, values can reach 100 mg/l at 1.50 m above bottom, just outside the Bay of Vilaine. The empirical calibration of the signal with independent...
Tipo: Text
Palavras-chave: Southern Brittany; MARS 3D numerical model; Acoustic backscattering; Acoustic current profiler; Waves; Circulations; Turbidity; Bretagne Sud; Modèle numérique MARS 3D; Rétrodiffusion acoustique; Profileur acoustique de courant; Vagues; Circulations; Turbidité.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/these-2325.pdf

Une formulation parabolique pour la propagation en profondeur finie des ondes de gravité en surface
Provedor de dados: 5
Autores: Mordane, Soumia; Maroihi, Kamal L; Orbi, Abdellatif; Chagdali, Mohamed.
This paper deals with the parabolic formulation of propagation equations of gravity waves in surface in terms of angular capability with respect to the privileged propagation direction. This parabolic formulation is obtained by splitting the Berkhoff equation operator into two parabolic operators representing progressive and regressive wave propagation. The use of Pade approximants permits to derive simultaneously parabolic equations for the transmitted waves and the reflected waves. Two well-known reference examples, which represent the propagation of the wave when a caustic occur, are studied numerically and the results are compared with those of the literature. (C) 2001 Ifremer/CNRS/IRD/Editions scientifiques et medicales Elsevier SAS.
Tipo: Text
Palavras-chave: Approximants de Padé; Diffraction–réfraction; Factorisation; Houle; Méthode parabolique; Pade approximants; Diffraction-refraction; Splitting; Waves; Parabolic method.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/00322/43356/42824.pdf

Modélisation morphodynamique d'une embouchure tidale : Application aux Passes d'entrée du Bassin d'Arcachon
Provedor de dados: 5
Autores: Cayocca, Florence.
The Arcachon tidal inlet exhibits a particularly active morphology due to strong tidal currents and rough wave conditions. During the past 300 years, maximum and minimum extents of the Cap Ferret sand spit have resulted in a difference of 8 km while two channels have alternatively allowed circulation between the lagoon and the ocean.   A bidimensional horizontal morphodynarnic model was developed in order to simulate the system evolution under tidal forcing alone or under combined tide and wave action. Modelling at a scale of decades requires the definition of mean annual wave and tide conditions which are representative with respect to sediment transport. Medium term results thus give general trends of evolution. Driven by these average conditions and...
Tipo: Text
Palavras-chave: Littoral drift; Sediment transport; Tide; Waves; Arcachon lagoon; Tidal inlet; Modelling; Morphodynamic; Dérive littorale; Transport sédimentaire; Marée; Houle; Bassin d'Arcachon; Modèle; Morphodynamique.
Ano: 1996
URL: http://archimer.ifremer.fr/doc/1996/these-4520.pdf

Modélisation du transport particulaire dans le Golfe du Lion en vue d'une application au devenir des traceurs radioactifs issus du Rhône
Provedor de dados: 5
Autores: Dufois, Francois.
Among the contaminants introduced into the environment, the artificial radionuclides appear particularly important to take into account because of their chemical toxicity and/or of their radiotoxicity. Some radionuclides present a high affinity with particles so that the study of the sediment dynamics is a useful preliminary to the study of their dispersion on the open sea. This thesis is focused on the fate of sediments in the Gulf of Lions (NW Mediterranean) and in particular on the impact of the Rhone River, which is the main source of particulate matter in the Gulf of Lions. In order to study the sediment transport mechanisms on various space and time scales, this thesis is based on mathematical modelling. The hydro-sedimentary model set up in the Gulf...
Tipo: Text
Palavras-chave: Waves; MARS 3D; Hydrodynamic; Radionuclides; Modelling; Sediment; Rhône prodelta; Gulf of Lions; Vagues; MARS 3D; Hydrodynamique; Radioéléments; Modélisation; Sédiment; Prodelta du Rhône; Golfe du Lion.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/these-6308.pdf

Interactions vagues-banquise en zones polaires
Provedor de dados: 5
Autores: Boutin, Guillaume.
Sea ice, which covers most of the ocean near the poles, is a key component of the climate system. Global warming is driving its massive melting, especially in the Arctic. Where sea ice cover decreases, fetch increases leading to more energetic sea states. This means potentially enhanced wavesice interactions effects in the future. The quick evolution of sea ice extent and volume combined with the intensification of human activities in polar regions urge us to improve our understanding of waves-ice interactions.Sea ice attenuates waves. They can however propagate through it and break it far into the ice cover. Attenuation depends on ice properties such as floe size, thickness, etc. Once broken, resulting floes are more likely to drift and melt. In addition,...
Tipo: Text
Palavras-chave: Vagues; Banquise; Modélisation; Zone Marginale de Glace; Waves; Sea ice; Model; Marginal Ice Zone.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00498/60968/64376.pdf

Observing Sea States
Provedor de dados: 5
Autores: 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

Field measurements of coastal waves and currents in Portugal and Greece
Provedor de dados: 5
Autores: Paillard, Michel; Prevosto, Marc; Barstow, Sf; Soares, Cg.
The MAST II WAVEMOD Project aimed at improving stochastic modelling of ocean waves and currents in coastal waters. In order to supplement existing data, two measurement campaigns were carried our, one on the Atlantic coast of Portugal, and, secondly, on the northern coast of Crete in the Mediterranean. The Portuguese measurements covered 7 months during winter 1993-1994, while off Crete, measurements started early in February 1994 and continued for 10 months, In both sites, two directional Waveriders and one non-directional Waverider were deployed along a transect our from the coast in water depths between 10 and 100 m. In addition, the Mediterranean site also incorporated measurements of mean current velocities. Available satellite data were analysed to...
Tipo: Text
Palavras-chave: Waves; Currents; Portugal; Greece.
Ano: 2000
URL: https://archimer.ifremer.fr/doc/00000/10506/66722.pdf

Simulation of radar backscatter and Doppler shifts of wave-current interaction in the presence of strong tidal current
Provedor de dados: 5
Autores: Hansen, M. W.; Kudryavtsev, V.; Chapron, Bertrand; Johannessen, J. A.; Collard, Fabrice; Dagestad, K. -f.; Mouche, A.a.
A radar imaging model including a Doppler shift module is presented for quantitative studies of radar observations of wave-current interaction in a strong tidal current regime. The model partitions the Doppler shift into the relative contribution arising from the motion of the backscattering facets including Bragg waves, specular points, and breaking waves that are advected by and interact with the underlying surface current. Simulated and observed normalized radar cross sections and Doppler shifts for different environmental conditions and radar parameters are compared and discussed. (C) 2012 Elsevier Inc. All rights reserved.
Tipo: Text
Palavras-chave: SAR; Tidal current; Waves; Normalized radar cross section; Doppler velocity.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00083/19438/17086.pdf

Extreme wave activity during 2013/2014 winter and morphological impacts along the Atlantic coast of Europe
Provedor de dados: 5
Autores: Masselink, Gerd; Castelle, Bruno; Scott, Tim; Dodet, Guillaume; Suanez, Serge; Jackson, Derek; Floc'H, France.
Studies of coastal vulnerability due to climate change tend to focus on the consequences of sea level rise, rather than the complex coastal responses resulting from changes to the extreme wave climate. Here we investigate the 2013/2014 winter wave conditions that severely impacted the Atlantic coast of Europe and demonstrate that this winter was the most energetic along most of the Atlantic coast of Europe since at least 1948. Along exposed open-coast sites, extensive beach and dune erosion occurred due to offshore sediment transport. More sheltered sites experienced less erosion and one of the sites even experienced accretion due to beach rotation induced by alongshore sediment transport. Storm wave conditions such as were encountered during the 2013/2014...
Tipo: Text
Palavras-chave: Waves; Storms; Beaches; Atlantic; Europe.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00606/71852/70473.pdf

GNSS-R nonlocal sea state dependencies: Model and empirical verification
Provedor de dados: 5
Autores: Chen-zhang, David D.; Ruf, Christopher S.; Ardhuin, Fabrice; Park, Jeonghwan.
Global Navigation Satellite System Reflectometry (GNSS-R) is an active, bistatic remote sensing technique operating at L-band frequencies. GNSS-R signals scattered from a rough ocean surface are known to interact with longer surface waves than traditional scatterometery and altimetry signals. A revised forward model for GNSS-R measurements is presented which assumes an ocean surface wave spectrum that is forced by other sources than just the local near-surface winds. The model is motivated by recent spaceborne GNSS-R observations that indicate a strong scattering dependence on significant wave height, even after controlling for local wind speed. This behavior is not well represented by the most commonly used GNSS-R scattering model, which features a...
Tipo: Text
Palavras-chave: Waves; Wind; Remote sensing.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00358/46909/46809.pdf

Marginal ice zone thickness and extent due to wave radiation stress.
Provedor de dados: 5
Autores: Sutherland, Peter; Dumont, Dany.
Ocean surface wave radiation stress represents the flux of momentum due to the waves. When waves are dissipated or reflected by sea ice, that momentum is absorbed or reflected, resulting in a horizontal forcing which frequently compresses the ice. In this work, wave radiation stress is used to estimate the compressive force applied by waves to the marginal ice zone (MIZ). It is balanced by an ice internal compressive stress based on Mohr-Coulomb granular materials theory. The ice internal stress can be related to ice thickness, allowing this force balance to be used as a model for the estimation of MIZ ice thickness. The model was validated and tested using data collected during two field campaigns in the St. Lawrence Estuary in 2016 and 2017. Modelled ice...
Tipo: Text
Palavras-chave: Sea ice; Momentum; Waves; Oceanic; Ice thickness.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00448/55994/57486.pdf

Overview of the Arctic Sea State and Boundary Layer Physics Program
Provedor de dados: 5
Autores: Thomson, Jim; Ackley, Stephen; Girard-ardhuin, Fanny; Ardhuin, Fabrice; Babanin, Alex; Boutin, Guillaume; Brozena, John; Cheng, Sukun; Collins, Clarence; Doble, Martin; Fairall, Chris; Guest, Peter; Gebhardt, Claus; Gemmrich, Johannes; Graber, Hans C.; Holt, Benjamin; Lehner, Susanne; Lund, Bjorn; Meylan, Michael H.; Maksym, Ted; Montiel, Fabien; Perrie, Will; Persson, Ola; Rainville, Luc; Rogers, W. Erick; Shen, Hui; Shen, Hayley; Squire, Vernon; Stammerjohn, Sharon; Stopa, Justin; Smith, Madison M.; Sutherland, Peter; Wadhams, Peter.
A large collaborative program has studied the coupled air‐ice‐ocean‐wave processes occurring in the Arctic during the autumn ice advance. The program included a field campaign in the western Arctic during the autumn of 2015, with in situ data collection and both aerial and satellite remote sensing. Many of the analyses have focused on using and improving forecast models. Summarizing and synthesizing the results from a series of separate papers, the overall view is of an Arctic shifting to a more seasonal system. The dramatic increase in open water extent and duration in the autumn means that large surface waves and significant surface heat fluxes are now common. When refreezing finally does occur, it is a highly variable process in space and time. Wind and...
Tipo: Text
Palavras-chave: Arctic; Waves; Autumn; Sea ice; Beaufort; Flux.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00437/54837/56313.pdf

Impact des installations ostréicoles sur l’hydrodynamique et la dynamique sédimentaire
Provedor de dados: 5
Autores: Kervella, Youen.
Oyster farm structures represent artificial obstacles which can disturb tidal currents and wave propagation, and thus modify sediment transport patterns. Local deposition may result from these modifications, in proportions that may threaten the oyster farming. The impact of structures on hydrodynamics, waves and currents, is investigated at different spatial scales by means of in-situ measurements, experimental tests and numerical modeling. These different approaches show that in the near-field, tidal currents are modified in terms of intensity and direction but there is no significant impact on the waves. On the other hand, at the scale of the oyster farm, a significant reduction of the current velocities and a large wave height attenuation are recorded....
Tipo: Text
Palavras-chave: Tables à huîtres; Envasement; Courants; Vagues; Sédiments; Impact; Oyster tables; Silting up; Currents; Waves; Sediment; Impact.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00011/12262/9043.pdf

Suspended Sediment Dynamics in the Macrotidal Seine Estuary (France) - Part 1: Numerical Modeling of Turbidity Maximum Dynamics
Provedor de dados: 5
Autores: Grasso, Florent; Verney, Romaric; Le Hir, Pierre; Thouvenin, Benedicte; Schulz, Elisabeth; Kervella, Youenn; Fard, I. Khojasteh Pour; Lemoine, J. -p.; Dumas, Franck; Garnier, Valerie.
Tidal pumping, baroclinic circulation and vertical mixing are known to be the main mechanisms responsible for the estuarine turbidity maximum (ETM) formation. However, the influence of hydro-meteorological conditions on ETM dynamics is still not properly grasped and requires further investigation to be quantified. Based on a realistic 3-dimensional numerical model of the macrotidal Seine Estuary (France) that accounts for mud and sand transport processes, the objective of this study is to quantify the influence of the main forcing (river flow, tides, waves) on the ETM location and mass changes. As expected, the ETM location is strongly modulated by semidiurnal tidal cycles and fortnightly timescales with a high sensitivity to river flow variations. The ETM...
Tipo: Text
Palavras-chave: Estuary; Mud; Sand; Hydrodynamics; Turbidity maximum; Waves; Measurement; Modeling.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00416/52770/53638.pdf

Analysis and Interpretation of Frequency–Wavenumber Spectra of Young Wind Waves
Provedor de dados: 5
Autores: 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

Spectral analysis of mean flow and turbulence forced by waves in a horizontally homogeneous zone of the Iroise sea A comparison with current times series measured by high-frequency radar
Provedor de dados: 5
Autores: Simon, Guillaume; Dumas, Franck; Duhaut, Thomas.
The 1D version of the Model for Applications at Regional Scale is used to parameterize the effects of sea surface waves in 2D in a horizontally homogeneous offshore zone of the Iroise sea. Here we present the first simulation of the Iroise sea including sea surface waves forcing, and more generally, the first study of a boundary layer including the Hasselmann force with a tidal wave. We use a single equation turbulence closure based on a non-local diagnosis for energetic and dissipation length scales. The turbulent energy flux at the surface due to whitecaps and the Hasselmann force induced by Stokes drift are assessed using the whole sea surface waves spectrum given by the Wave Watch Third generation model. The ability of the parameterization to reproduce...
Tipo: Text
Palavras-chave: Ocean turbulence; Waves; Stokes drift; Iroise sea; MARS; High-frequency radar; OSCR.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00053/16467/14087.pdf

Wave-Current Interactions at Meso and Submesoscales: Insights from Idealized Numerical Simulations
Provedor de dados: 5
Autores: Villas Bôas, Ana B.; Cornuelle, Bruce. D.; Mazloff, Matthew. R.; Gille, Sarah. T.; Ardhuin, Fabrice.
Surface gravity waves play a major role in the exchange of momentum, heat, energy, and gases between the ocean and the atmosphere. The interaction between currents and waves can lead to variations in the wave direction, frequency, and amplitude. In the present work, we use an ensemble of synthetic currents to force the wave model WAVEWATCH III and assess the relative impact of current divergence and vorticity in modifying several properties of the waves, including direction, period, directional spreading, and significant wave height (Hs). We find that the spatial variability of Hs is highly sensitive to the nature of the underlying current and that refraction is the main mechanism leading to gradients of Hs. The results obtained using synthetic currents...
Tipo: Text
Palavras-chave: Ocean; Sea/ocean surface; Atmosphere-ocean interaction; Mesoscale processes; Waves; Oceanic; Numerical analysis/modeling.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00654/76592/77740.pdf

Observed and predicted vertical suspended sediment concentration profiles and bedforms in oscillatory-only flow
Provedor de dados: 27
Autores: Williams, J.J.; Bell, P.S.; Thorne, P.D.; Trouw, K.; Hardcastle, P.J.; Humphrey, J.D.
Measurements of hydrodynamic conditions and vertical suspended sediment concentration profiles, C-profiles, have been obtained above rippled sandy beds in a large wave flume. Measured values of wave height and period, water depth and sediment properties are used in well-known formulae to predict sediment dynamics and bed shear stresses due to waves. These data are then used in an existing convective model and a new model to predict C-profiles. Measured C-profiles and C-profiles predicted by the new model are shown to agree well for a range of grain sizes and wave conditions. Grain-scale bed roughness, defined using data from the model, is found to vary with the wave mobility number. Values for the wave mixing coefficient derived using the new model are...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Benthic boundary layer; Flow; Flow; Flow; Model studies; Oscillatory flow; Resuspended sediments; Sand; Sediment dynamics; Vertical profiles; Waves; Waves.
Ano: 2000
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7388