|
|
|
| Registros recuperados: 129 | |
|
|
| Ardhuin, Fabrice; Stopa, Justin; Chapron, Bertrand; Collard, Fabrice; Smith, Madison; Thomson, Jim; Doble, Martin; Blomquist, Byron; Persson, Ola; Collins, Clarence O., Iii; Wadhams, Peter. |
| Measurements of wave heights in marginal ice zones are limited to very few in situ data. Here we revisit the linear and quasilinear theories of Synthetic Aperture Radar imaging of waves in the particular case of waves in sea ice. Instead of only working with spectra, we have developed an iterative nonlinear algorithm to estimate phase-resolved deterministic maps of wave-induced orbital velocities, from which elevation spectra can be derived. Application of this algorithm to Sentinel 1A wave mode images in the Southern Ocean shows that it produces reasonable results for swells in all directions except when they propagate at a few degrees off the range direction. The estimate of wave parameters is expected to work best when the shortest wave components,... |
| Tipo: Text |
Palavras-chave: SAR; Sentinel-1A; Ocean waves; Sea ice. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00361/47214/47451.pdf |
| |
|
|
| Thomson, Jim; Fan, Yalin; Stammerjohn, Sharon; Stopa, Justin; Erick Rogers, W.; Girard-ardhuin, Fanny; Ardhuin, Fabrice; Shen, Hayley; Perrie, Will; Shen, Hui; Ackley, Steve; Babanin, Alex; Liu, Qingxiang; Guest, Peter; Maksym, Ted; Wadhams, Peter; Fairall, Chris; Persson, Ola; Doble, Martin; Graber, Hans; Lund, Bjoern; Squire, Vernon; Gemmrich, Johannes; Lehner, Susanne; Holt, Benjamin; Meylan, Mike; Brozena, John; Bidlot, Jean-raymond. |
| The sea state of the Beaufort and Chukchi seas is controlled by the wind forcing and the amount of ice-free water available to generate surface waves. Clear trends in the annual duration of the open water season and in the extent of the seasonal sea ice minimum suggest that the sea state should be increasing, independent of changes in the wind forcing. Wave model hindcasts from four selected years spanning recent conditions are consistent with this expectation. In particular, larger waves are more common in years with less summer sea ice and/or a longer open water season, and peak wave periods are generally longer. The increase in wave energy may affect both the coastal zones and the remaining summer ice pack, as well as delay the autumn ice-edge advance.... |
| Tipo: Text |
Palavras-chave: Sea ice; Arctic Ocean; Ocean surface waves. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00345/45590/45202.pdf |
| |
|
|
| Morrow, Rosemary; Fu, Lee-lueng; Ardhuin, Fabrice; Benkiran, Mounir; Chapron, Bertrand; Cosme, Emmanuel; D’ovidio, Francesco; Farrar, J. Thomas; Gille, Sarah T.; Lapeyre, Guillaume; Le Traon, Pierre-yves; Pascual, Ananda; Ponte, Aurelien; Qiu, Bo; Rascle, Nicolas; Ubelmann, Clement; Wang, Jinbo; Zaron, Edward D.. |
| The future international Surface Water and Ocean Topography (SWOT) Mission, planned for launch in 2021, will make high-resolution 2D observations of sea-surface height using SAR radar interferometric techniques. SWOT will map the global and coastal oceans up to 77.6∘ latitude every 21 days over a swath of 120 km (20 km nadir gap). Today’s 2D mapped altimeter data can resolve ocean scales of 150 km wavelength whereas the SWOT measurement will extend our 2D observations down to 15–30 km, depending on sea state. SWOT will offer new opportunities to observe the oceanic dynamic processes at scales that are important in the generation and dissipation of kinetic energy in the ocean, and that facilitate the exchange of energy between the ocean interior and the... |
| Tipo: Text |
Palavras-chave: Ocean mesoscale circulation; Satellite altimetry; SAR-interferometry; Tides and internal tides; Calibration-validation. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00495/60685/64181.pdf |
| |
|
| |
|
|
| Ardhuin, Fabrice; Jenkins, A; Hauser, D; Reniers, A; Chapron, Bertrand. |
| The availability of new operational services for ocean circulation modeling presents a unique opportunity to rethink the operational forecasting of ocean waves and how circulation and waves may be combined to provide a better understanding of the upper ocean and enhanced services to society. The large-scale oil spill caused by the wreck of the tanker Prestige off the Spanish coast in November 2002, and uncertainties on the fate of that pollution, illustrated the gaps in means of observations and knowledge of relevant processes. The idea of a coupled atmosphere-waves-ocean model was proposed by Klaus Hasselmann [Hasselmann, 1991], in the context of climate modeling. As waves are the "gearbox" between the atmosphere and the ocean, a detailed understanding of... |
| Tipo: Text |
|
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-6330.pdf |
| |
|
|
| De Carlo, M; Ardhuin, Fabrice; Le Pichon, A. |
| Between 0.1 and 0.5 Hz, infrasound signals recorded in the atmosphere are dominated by ocean-generated noise called microbaroms. Microbaroms propagate through the atmosphere over thousands of kilometers due to low absorption and efficient ducting between the ground and the stratopause. Different theoretical models have been developed to characterize the source of microbaroms, all based on the second-order non-linear interaction of ocean waves. While early theories considered an infinite ocean depth and a source radiation depending on the acoustic wave elevation angle, other works have approximated the radiation pattern as a monopole, and found a considerable effect of the water depth. This paper reviews these models and extends the previous theories to the... |
| Tipo: Text |
Palavras-chave: Interface waves; Wave propagation; Infrasound. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00602/71378/69827.pdf |
| |
|
|
| Dodet, Guillaume; Piolle, Jean-francois; Quilfen, Yves; Abdallah, Saleh; Accensi, Mickael; Ardhuin, Fabrice; Ash, Ellis; Bidlot, Jean-raymond; Gommenginger, Christine; Marechal, Gwendal; Passaro, Marcello; Quartly, Graham; Stopa, Justin; Timmermans, Ben; Young, Ian; Cipollini, Paolo; Donlon, Craig. |
| Sea state data are of major importance for climate studies, marine engineering, safety at sea, and coastal management. However, long-term sea state datasets are sparse and not always consistent, and sea state data users still mostly rely on numerical wave models for research and engineering applications. Facing the urgent need for a sea state Climate Data Record, the Global Climate Observing System has listed Sea State as an Essential Climate Variable (ECV), fostering the launch in 2018 of the Sea State Climate Change Initiative (CCI). The CCI is a program of the European Space Agency, whose objective is to realize the full potential of global Earth Observation archives established by ESA and its member states in order to contribute to the ECV database.... |
| Tipo: Text |
|
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00634/74633/74527.pdf |
| |
|
|
| Popp, Thomas; Hegglin, Michaela I.; Hollmann, Rainer; Ardhuin, Fabrice; Bartsch, Annett; Bastos, Ana; Bennett, Victoria; Boutin, Jacqueline; Brockmann, Carsten; Buchwitz, Michael; Chuvieco, Emilio; Ciais, Philippe; Dorigo, Wouter; Ghent, Darren; Jones, Richard; Lavergne, Thomas; Merchant, Christopher J.; Meyssignac, Benoit; Paul, Frederic; Quegan, Shaun; Sathyendranath, Shubha; Scanlon, Tracy; Schröder, Marc; Simis, Stefan G. H.; Willén, Ulrika. |
| Climate Data Records (CDRs) of Essential Climate Variables (ECVs) as defined by the Global Climate Observing System (GCOS) derived from satellite instruments help to characterize the main components of the Earth system, to identify the state and evolution of its processes, and to constrain the budgets of key cycles of water, carbon and energy. The Climate Change Initiative (CCI) of the European Space Agency (ESA) coordinates the derivation of CDRs for 21 GCOS ECVs. The combined use of multiple ECVs for Earth system science applications requires consistency between and across their respective CDRs. As a comprehensive definition for multi-ECV consistency is missing so far, this study proposes defining consistency on three levels: (1) consistency in format... |
| Tipo: Text |
|
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00635/74700/74639.pdf |
| |
|
|
| Schlembach, Florian; Passaro, Marcello; Quartly, Graham D.; Kurekin, Andrey; Nencioli, Francesco; Dodet, Guillaume; Piollé, Jean-francois; Ardhuin, Fabrice; Bidlot, Jean; Schwatke, Christian; Seitz, Florian; Cipollini, Paolo; Donlon, Craig. |
| Radar altimeters have been measuring ocean significant wave height for more than three decades, with their data used to record the severity of storms, the mixing of surface waters and the potential threats to offshore structures and low-lying land, and to improve operational wave forecasting. Understanding climate change and long-term planning for enhanced storm and flooding hazards are imposing more stringent requirements on the robustness, precision, and accuracy of the estimates than have hitherto been needed. Taking advantage of novel retracking algorithms, particularly developed for the coastal zone, the present work aims at establishing an objective baseline processing chain for wave height retrieval that can be adapted to all satellite missions. In... |
| Tipo: Text |
Palavras-chave: Satellite altimetry; LRM; Delay-Doppler; Altimetry; SAR altimetry; Significant wave height; Round robin; Assessment; Comparison; Retracking; ESA; Climate change initiative. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00630/74172/73742.pdf |
| |
|
|
| Ardhuin, Fabrice; Stutzmann, Eleonore; Schimmel, Martin; Mangeney, Anne. |
| Noise with periods 3 to 10 s, ubiquitous in seismic records, is expected to be mostly generated by pairs of ocean wave trains of opposing propagation directions with half the seismic frequency. Here we present the first comprehensive numerical model of microseismic generation by random ocean waves, including ocean wave reflections. Synthetic and observed seismic spectra are well correlated (r > 0.85). On the basis of the model results, noise generation events can be clustered in three broad classes: wind waves with a broad directional spectrum (class I), sea states with a significant contribution of coastal reflections (class II), and the interaction of two independent wave systems (class III). At seismic stations close to western coasts, noise... |
| Tipo: Text |
|
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00044/15531/12926.pdf |
| |
|
| |
|
|
| 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 |
|
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00658/77056/78354.pdf |
| |
|
|
| Dodet, Guillaume; Melet, Angélique; Ardhuin, Fabrice; Bertin, Xavier; Idier, Déborah; Almar, Rafael. |
| Surface gravity waves generated by winds are ubiquitous on our oceans and play a primordial role in the dynamics of the ocean–land–atmosphere interfaces. In particular, wind-generated waves cause fluctuations of the sea level at the coast over timescales from a few seconds (individual wave runup) to a few hours (wave-induced setup). These wave-induced processes are of major importance for coastal management as they add up to tides and atmospheric surges during storm events and enhance coastal flooding and erosion. Changes in the atmospheric circulation associated with natural climate cycles or caused by increasing greenhouse gas emissions affect the wave conditions worldwide, which may drive significant changes in the wave-induced coastal hydrodynamics.... |
| Tipo: Text |
Palavras-chave: Wind waves; Sea level; Coastal zone; Climate change. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00509/62046/66721.pdf |
| |
|
|
| Cox, Rónadh; Ardhuin, Fabrice; Dias, Frédéric; Autret, Ronan; Beisiegel, Nicole; Earlie, Claire S.; Herterich, James G.; Kennedy, Andrew; Paris, Raphaël; Raby, Alison; Schmitt, Pal; Weiss, Robert. |
| Coastal boulder deposits (CBD), transported by waves at elevations above sea level and substantial distances inland, are markers for marine incursions. Whether they are tsunami or storm deposits can be difficult to determine, but this is of critical importance because of the role that CBD play in coastal hazard analysis. Equations from seminal work by Nott (1997), here referred to as the Nott Approach, are commonly employed to calculate nominal wave heights from boulder masses as a means to discriminate between emplacement mechanisms. Systematic review shows that this approach is based on assumptions that are not securely founded and that direct relationships cannot be established between boulder measurements and wave heights. A test using an unprecedented... |
| Tipo: Text |
Palavras-chave: Coastal boulder deposits; Storm waves; Tsunami; Hydrodynamic equations; Coastal erosion; Coastal hazard; Coastal geomorphology; Wave modeling. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00610/72237/71040.pdf |
| |
|
|
| Roland, Aron; Ardhuin, Fabrice. |
| The development of numerical wave models for coastal applications, including coupling with ocean circulation models, has spurred an ongoing effort on theoretical foundations, numerical techniques, and physical parameterizations. Some important aspects of this effort are reviewed here, and results are shown in the case of the French Atlantic and Channel coast using version 4.18 of the WAVEWATCH III R model. Compared to previous results, the model errors have been strongly reduced thanks to, among other things, the introduction of currents, coastal reflection, and bottom sediment types. This last item is described here for the first time, allowing unprecedented accuracy at some sites along the French Atlantic Coast. The adequate resolution, necessary to... |
| Tipo: Text |
Palavras-chave: Wave modeling; Bottom friction; Coupling; Wave-current interaction. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00192/30288/29918.pdf |
| |
|
|
| 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 |
| |
|
|
| Bourras, Denis; Cambra, Remi; Marié, Louis; Bouin, Marie-noëlle; Baggio, Lucio; Branger, Hubert; Beghoura, Houda; Reverdin, Gilles; Dewitte, Boris; Paulmier, Aurélien; Maes, Christophe; Ardhuin, Fabrice; Pairaud, Ivane; Fraunié, Philippe; Luneau, Christopher; Hauser, Danièle. |
| Turbulent fluxes at the air‐sea interface are estimated with data collected in 2011 to 2017 with a low‐profile platform during six experiments in four regions. The observations were carried out with moderate winds (2‐10 m s‐1) and averaged wave heights of 1.5 m. Most of the time, there was a swell, with an averaged wave age (the ratio between wave phase speed and wind speed) being equal to 2.8±1.6. Three flux calculation methods are used, namely the eddy‐covariance (EC), the inertial‐dissipation (ID), and the bulk methods. For the EC method, a spectral technique is proposed to correct wind data from platform motion. A mean bias affecting the friction velocity (u*) is then evaluated. The comparison between EC u* and ID u* estimates suggests that a constant... |
| Tipo: Text |
|
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00503/61436/65156.pdf |
| |
|
|
| 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 |
|
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00416/52778/53657.pdf |
| |
|
| |
|
|
| Benetazzo, Alvise; Serafino, Francesco; Bergamasco, Filippo; Ludeno, Giovanni; Ardhuin, Fabrice; Sutherland, Peter; Sclavo, Mauro; Barbariol, Francesco. |
| The use of spatial and spatio-temporal data is rapidly changing the paradigm of wind wave observations, which have been traditionally restricted to time series from single-point measurements (e.g. from buoys, wave gauges). Active and passive 2D remote sensors mounted on platforms, ships, airplanes and satellites are now becoming standards in the oceanographic community and industry. Given the covered area ranging from centimeters to kilometers, such sensors are now a valuable tool for ocean and coastal observations. In this paper, we intercompare spatio-temporal wind wave data acquired with two state-of-the-art techniques, namely the stereo wave imaging and the X-band marine radar. The comparison was performed by operating the two instruments on an... |
| Tipo: Text |
Palavras-chave: Directional wave observations; Stereo wave imaging; X-band marine radar; Modulation Transfer Function (MTF); Sea technology. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00428/53934/55108.pdf |
| |
| Registros recuperados: 129 | |
|
|
|
