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Registros recuperados: 8
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Airborne Remote Sensing of Wave Propagation in the Marginal Ice Zone ArchiMer
Sutherland, Peter; Brozena, John; Rogers, W. Erick; Doble, Martin; Wadhams, Peter.
Airborne scanning lidar was used to measure the evolution of the surface wave field in the marginal ice zone (MIZ) during two separate wave events in the Beaufort Sea in October 2015. The lidar data consisted of a 2‐D field of surface elevation with horizontal resolutions between 17 and 33 cm, over a swath approximately 150‐220 m wide, centred on the ground track of the aircraft. Those data were used to compute directional wavenumber spectra of the surface wave field. Comparison with nearly collocated buoy data found the lidar and buoy measurements to be generally consistent. During the first event, waves travelling from open water into the ice were attenuated by the ice. The low spectral spreading and k7/4 spectral dependence of the attenuation was...
Tipo: Text Palavras-chave: Surface waves; Marginal ice zone; Wave attenuation; Wave growth rate; Air-sea-ice; Airborne scanning lidar.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00439/55086/56526.pdf
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Emerging trends in the sea state of the Beaufort and Chukchi seas ArchiMer
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
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Measuring ocean waves in sea ice using SAR imagery: A quasi-deterministic approach evaluated with Sentinel-1 and in situ data ArchiMer
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
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Ocean waves across the Arctic: attenuation due to dissipation dominates over scattering for periods longer than 19 s ArchiMer
Ardhuin, Fabrice; Sutherland, Peter; Doble, Martin; Wadhams, Peter.
The poorly understood attenuation of surface waves in sea ice is generally attributed to the combination of scattering and dissipation. Scattering and dissipation have very different effects on the directional and temporal distribution of wave energy, making it possible to better understand their relative importance by analysis of swell directional spreading and arrival times. Here we compare results of a spectral wave model – using adjustable scattering and dissipation attenuation formulations – with wave measurements far inside the ice pack. In this case, scattering plays a negligible role in the attenuation of long swells. Specifically, scattering-dominated attenuation would produce directional wave spectra much broader than the ones recorded, and swell...
Tipo: Text Palavras-chave: Ocean waves; Sea ice; Tara; DAMOCLES.
Ano: 2016 URL: http://archimer.ifremer.fr/doc/00333/44455/44127.pdf
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Overview of the Arctic Sea State and Boundary Layer Physics Program ArchiMer
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
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Satellite Observations for Detecting and Forecasting Sea-Ice Conditions: A Summary of Advances Made in the SPICES Project by the EU’s Horizon 2020 Programme ArchiMer
Mäkynen, Marko; Haapala, Jari; Aulicino, Giuseppe; Balan-sarojini, Beena; Balmaseda, Magdalena; Gegiuc, Alexandru; Girard-ardhuin, Fanny; Hendricks, Stefan; Heygster, Georg; Istomina, Larysa; Kaleschke, Lars; Karvonen, Juha; Krumpen, Thomas; Lensu, Mikko; Mayer, Michael; Parmiggiani, Flavio; Ricker, Robert; Rinne, Eero; Schmitt, Amélie; Similä, Markku; Tietsche, Steffen; Tonboe, Rasmus; Wadhams, Peter; Winstrup, Mai; Zuo, Hao.
The detection, monitoring, and forecasting of sea-ice conditions, including their extremes, is very important for ship navigation and offshore activities, and for monitoring of sea-ice processes and trends. We summarize here recent advances in the monitoring of sea-ice conditions and their extremes from satellite data as well as the development of sea-ice seasonal forecasting capabilities. Our results are the outcome of the three-year (2015–2018) SPICES (Space-borne Observations for Detecting and Forecasting Sea-Ice Cover Extremes) project funded by the EU’s Horizon 2020 programme. New SPICES sea-ice products include pancake ice thickness and degree of ice ridging based on synthetic aperture radar imagery, Arctic sea-ice volume and export derived from...
Tipo: Text
Ano: 2020 URL: https://archimer.ifremer.fr/doc/00622/73389/72601.pdf
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Wave Attenuation Through an Arctic Marginal Ice Zone on 12 October, 2015: 1. Measurement of Wave Spectra and Ice Features From Sentinel-1A ArchiMer
Stopa, J. E.; Ardhuin, Fabrice; Thomson, Jim; Smith, Madison M.; Kohout, Alison; Doble, Martin; Wadhams, Peter.
A storm with significant wave heights exceeding 4 m occurred in the Beaufort Sea on 11 to 13 October, 2015. The waves and ice were captured on 12 October by the Synthetic Aperture Radar (SAR) on board Sentinel‐1A, with Interferometric Wide swath images covering 400 × 1100 km at 10 m resolution. This dataset allows the estimation of wave spectra across the marginal ice zone (MIZ) every 5 km, over 400 km of sea ice. Since ice attenuates waves with wavelengths shorter than 50 m in a few kilometers, the longer waves are clearly imaged by SAR in sea ice. Obtaining wave spectra from the image requires a careful estimation of the blurring effect produced by unresolved wavelengths in the azimuthal direction. Using in‐situ wave buoy measurements as reference, we...
Tipo: Text Palavras-chave: Wave-ice interaction; Arctic Ocean marginal ice zone; Sentinel-1A SAR; Arctic Sea State Boundary Layer Physics Program; Remote sensing; Wave attenuation.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00439/55084/56519.pdf
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Wave Attenuation Through an Arctic Marginal Ice Zone on 12 October 2015: 2. Numerical Modeling of Waves and Associated Ice Breakup ArchiMer
Ardhuin, Fabrice; Boutin, Guillaume; Stopa, Justin; Girard-ardhuin, Fanny; Melsheimer, Christian; Thomson, Jim; Kohout, Alison; Doble, Martin; Wadhams, Peter.
Many processes that affect ocean surface gravity waves in sea ice give rise to attenuation rates that vary with both wave frequency and amplitude. Here we particularly test the possible effects of basal friction, scattering by ice floes, and dissipation in the ice layer due to dislocations, and ice breakup by the waves. The possible influence of these processes is evaluated in the marginal ice zone of the Beaufort Sea, where extensive wave measurements were performed. The wave data includes in situ measurements and the first kilometer-scale map of wave heights provided by Sentinel-1 SAR imagery on 12 October 2015, up to 400 km into the ice. We find that viscous friction at the base of an ice layer gives a dissipation rate that may be too large near the ice...
Tipo: Text Palavras-chave: Wind-waves; Sea ice; WAVEWATCH III; SAR; Beaufort; Arctic.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00462/57372/59439.pdf
Registros recuperados: 8
Primeira ... 1 ... Última
 

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