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Registros recuperados: 17 | |
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Ricker, Robert; Girard-ardhuin, Fanny; Krumpen, Thomas; Lique, Camille. |
Sea ice volume export through the Fram Strait represents an important freshwater input to the North Atlantic, which could in turn modulate the intensity of the thermohaline circulation. It also contributes significantly to variations in Arctic ice mass balance. We present the first estimates of winter sea ice volume export through the Fram Strait using CryoSat-2 sea ice thickness retrievals and three different ice drift products for the years 2010 to 2017. The monthly export varies between -21 and -540 km(3). We find that ice drift variability is the main driver of annual and interannual ice volume export variability and that the interannual variations in the ice drift are driven by large-scale variability in the atmospheric circulation captured by the... |
Tipo: Text |
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Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00460/57122/59048.pdf |
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Tournadre, Jean; Bouhier, Nicolas; Girard-ardhuin, Fanny; Remy, F.. |
Basal melting of floating ice shelves and iceberg calving constitute the two almost equal paths of freshwater flux between the Antarctic ice cap and the Southern Ocean. The largest icebergs (>100 km2) transport most of the ice volume but their basal melting is small compared to their breaking into smaller icebergs that constitute thus the major vector of freshwater. The archives of nine altimeters have been processed to create a database of small icebergs (<8 km2) within open water containing the positions, sizes, and volumes spanning the 1992–2014 period. The intercalibrated monthly ice volumes from the different altimeters have been merged in a homogeneous 23 year climatology. The iceberg size distribution, covering the 0.1–10,000 km2 range,... |
Tipo: Text |
Palavras-chave: Iceberg; Altimetry; Southern Ocean. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00307/41863/41114.pdf |
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Ricker, Robert; Hendricks, Stefan; Girard-ardhuin, Fanny; Kaleschke, Lars; Lique, Camille; Tian-kunze, Xiangshan; Nicolaus, Marcel; Krumpen, Thomas. |
An anomalous warm winter 2015–2016 lead to the lowest winter ice extent and highlights the sensitivity of the Arctic sea ice. Here we use the 6 year record of an improved sea ice thickness product retrieved from data fusion of CryoSat-2 radar altimetry and Soil Moisture and Ocean Salinity radiometry measurements to examine the impact of recent temperature trend on the Arctic ice mass balance. Between November 2015 and March 2016, we find a consistent drop of cumulative freezing degree days across the Arctic, with a negative peak anomaly of about 1000 degree days in the Barents Sea, coinciding with an Arctic-wide average thinning of 10 cm in March with respect to the 6 year average. In particular, the loss of ice volume is associated with a significant... |
Tipo: Text |
Palavras-chave: Arctic sea ice; Sea ice thickness; Remote sensing; CryoSat-2; SMOS; Sea ice growth. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00382/49325/49701.pdf |
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Holding, Thomas; Ashton, Ian; Shutler, Jamie D.; Land, Peter E.; Nightingale, Philip D.; Rees, Andrew P.; Brown, Ian; Piolle, Jean-francois; Kock, Annette; Bange, Hermann W.; Woolf, David K.; Goddijn-murphy, Lonneke; Pereira, Ryan; Paul, Frederic; Girard-ardhuin, Fanny; Chapron, Bertrand; Rehder, Gregor; Ardhuin, Fabrice; Donlon, Craig J.. |
The flow (flux) of climate-critical gases, such as carbon dioxide (CO2), between the ocean and the atmosphere is a fundamental component of our climate and an important driver of the biogeochemical systems within the oceans. Therefore, the accurate calculation of these air–sea gas fluxes is critical if we are to monitor the oceans and assess the impact that these gases are having on Earth's climate and ecosystems. FluxEngine is an open-source software toolbox that allows users to easily perform calculations of air–sea gas fluxes from model, in situ, and Earth observation data. The original development and verification of the toolbox was described in a previous publication. The toolbox has now been considerably updated to allow for its use as a Python... |
Tipo: Text |
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Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00598/70983/69247.pdf |
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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 |
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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 |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00622/73389/72601.pdf |
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Shutler, Jamie D.; Quartly, Graham D.; Donlon, Craig J.; Sathyendranath, Shubha; Platt, Trevor; Chapron, Bertrand; Johannessen, Johnny A.; Girard-ardhuin, Fanny; Nightingale, Philip D.; Woolf, David K.; Hoyer, Jacob L.. |
Physical oceanography is the study of physical conditions, processes and variables within the ocean, including temperature-salinity distributions, mixing of the water column, waves, tides, currents and air-sea interaction processes. Here we provide a critical review of how satellite sensors are being used to study physical oceanography processes at the ocean surface and its borders with the atmosphere and sea ice. The paper begins by describing the main sensor types that are used to observe the oceans (visible, thermal infrared and microwave) and the specific observations that each of these sensor types can provide. We then present a critical review of how these sensors and observations are being used to study: (i) ocean surface currents, (ii) storm... |
Tipo: Text |
Palavras-chave: Atmosphere-ocean interface; Sea ice; Remote sensing; Surface currents; Storm surge; Surface heat fluxes; Atmosphere-ocean gas fluxes; Oceanography. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00333/44405/44318.pdf |
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Shutler, Jamie D.; Land, Peter E.; Piolle, Jean-francois; Woolf, David K.; Goddijn-murphy, Lonneke; Paul, Frederic; Girard-ardhuin, Fanny; Chapron, Bertrand; Donlon, Craig J.. |
The air-sea flux of greenhouse gases (e.g. carbon dioxide, CO2) is a critical part of the climate system and a major factor in the biogeochemical development of the oceans. More accurate and higher resolution calculations of these gas fluxes are required if we are to fully understand and predict our future climate. Satellite Earth observation is able to provide large spatial scale datasets that can be used to study gas fluxes. However, the large storage requirements needed to host such data can restrict its use by the scientific community. Fortunately, the development of cloud-computing can provide a solution. Here we describe an open source air-sea CO2 flux processing toolbox called the ‘FluxEngine’, designed for use on a cloud-computing infrastructure.... |
Tipo: Text |
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Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00309/42034/41333.pdf |
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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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Sumata, Hiroshi; Lavergne, Thomas; Girard-ardhuin, Fanny; Kimura, Noriaki; Tschudi, Mark A.; Kauker, Frank; Karcher, Michael; Gerdes, Rudiger. |
An intercomparison of four low-resolution remotely sensed ice-drift products in the Arctic Ocean is presented. The purpose of the study is to examine the uncertainty in space and time of these different drift products. The comparison is based on monthly mean ice drifts from October 2002 to December 2006. The ice drifts were also compared with available buoy data. The result shows that the differences of the drift vectors are not spatially uniform, but are covariant with ice concentration and thickness. In high (low) ice-concentration areas, the differences are small (large), and in thick (thin) ice-thickness areas, the differences are small (large). A comparison with the drift deduced from buoys reveals that the error of the drift speed depends on the... |
Tipo: Text |
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Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00203/31395/29783.pdf |
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Tournadre, Jean; Bouhier, Nicolas; Girard-ardhuin, Fanny; Remy, F.. |
Large uncertainties exist on the volume of ice transported by the Southern Ocean large icebergs, a key parameter for climate studies, because of the paucity of information, especially on iceberg thickness. Using icebergs tracks from the National Ice Center (NIC) and Brigham Young University (BYU) databases to select altimeter data over icebergs and a method of analysis of altimeter waveforms, a database of 5366 icebergs freeboard elevation, length, and backscatter covering the 2002–2012 period has been created. The database is analyzed in terms of distributions of freeboard, length, and backscatter showing differences as a function of the iceberg's quadrant of origin. The database allows to analyze the temporal evolution of icebergs and to estimate a melt... |
Tipo: Text |
Palavras-chave: Iceberg; Antarctica; Altimetry; Ice balance. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00256/36719/35333.pdf |
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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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Woolf, D.k.; Shutler, J.d.; Goddijn‐murphy, L.; Watson, A.j.; Chapron, Bertrand; Nightingale, P.d.; Donlon, C.j.; Piskozub, J.; Yelland, M.j.; Ashton, Ian; Holding, T.; Schuster, U.; Girard-ardhuin, Fanny; Grouazel, Antoine; Piolle, Jean-francois; Warren, M.; Wrobel‐niedzwiecka, I.; Land, P.e.; Torres, R.; Prytherch, J.; Moat, B.; Hanafin, J.; Ardhuin, Fabrice; Paul, Frederic. |
The contemporary air‐sea flux of CO2 is investigated by the use of an air‐sea flux equation, with particular attention to the uncertainties in global values and their origin with respect to that equation. In particular, uncertainties deriving from the transfer velocity and from sparse upper ocean sampling are investigated. Eight formulations of air‐sea gas transfer velocity are used to evaluate the combined standard uncertainty resulting from several sources of error. Depending on expert opinion, a standard uncertainty in transfer velocity of either ~5% or ~10% can be argued and that will contribute a proportional error in air‐sea flux. The limited sampling of upper ocean fCO2 is readily apparent in the Surface Ocean CO2 Atlas (SOCAT) databases. The effect... |
Tipo: Text |
Palavras-chave: Carbon dioxide; Air-sea flux; Uncertainty; Transfer velocity; Sampling. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00513/62450/66754.pdf |
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Le Traon, Pierre-yves; Antoine, D.; Bentamy, Abderrahim; Bonekamp, H.; Breivik, L. A.; Chapron, Bertrand; Corlett, G.; Dibarboure, G.; Digiacomo, P.; Donlon, C.; Faugere, Y.; Font, J.; Girard-ardhuin, Fanny; Gohin, Francis; Johannessen, J. A.; Kamachi, M.; Lagerloef, G.; Lambin, J.; Larnicol, Gilles; Le Borgne, P.; Leuliette, E.; Lindstrom, E.; Martin, M. J.; Maturi, E.; Miller, L.; Mingsen, L.; Morrow, R.; Reul, Nicolas; Rio, Myriam; Roquet, H.; Santoleri, R.; Wilkin, J.. |
The paper gives an overview of the development of satellite oceanography over the past five years focusing on the most relevant issues for operational oceanography. Satellites provide key essential variables to constrain ocean models and/or serve downstream applications. New and improved satellite data sets have been developed and have directly improved the quality of operational products. The status of the satellite constellation for the last five years was, however, not optimal. Review of future missions shows clear progress and new research and development missions with a potentially large impact for operational oceanography should be demonstrated. Improvement of data assimilation techniques and developing synergetic use of high resolution satellite... |
Tipo: Text |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00270/38094/36245.pdf |
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Itkin, Polona; Spreen, Gunnar; Cheng, Bin; Doble, Martin; Girard-ardhuin, Fanny; Haapala, Jari; Hughes, Nick; Kaleschke, Lars; Nicolaus, Marcel; Wilkinson, Jeremy. |
Arctic sea ice has displayed significant thinning as well as an increase in drift speed in recent years. Taken together this suggests an associated rise in sea ice deformation rate. A winter and spring expedition to the sea ice covered region north of Svalbard–the Norwegian young sea ICE2015 expedition (N-ICE2015)—gave an opportunity to deploy extensive buoy arrays and to monitor the deformation of the first-year and second-year ice now common in the majority of the Arctic Basin. During the 5 month long expedition, the ice cover underwent several strong deformation events, including a powerful storm in early February that damaged the ice cover irreversibly. The values of total deformation measured during N-ICE2015 exceed previously measured values in the... |
Tipo: Text |
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Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00392/50365/51067.pdf |
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Stopa, Justin; Ardhuin, Fabrice; Girard-ardhuin, Fanny. |
Over the past decade, the diminishing Arctic sea ice has impacted the wave field, which depends on the ice-free ocean and wind. This study characterizes the wave climate in the Arctic spanning 1992–2014 from a merged altimeter data set and a wave hindcast that uses CFSR winds and ice concentrations from satellites as input. The model performs well, verified by the altimeters, and is relatively consistent for climate studies. The wave seasonality and extremes are linked to the ice coverage, wind strength, and wind direction, creating distinct features in the wind seas and swells. The altimeters and model show that the reduction of sea ice coverage causes increasing wave heights instead of the wind. However, trends are convoluted by interannual climate... |
Tipo: Text |
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Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00347/45816/45461.pdf |
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Registros recuperados: 17 | |
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