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| Registros recuperados: 52 | |
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| Miles, Martin W.; Divine, Dmitry V.; Furevik, Tore; Jansen, Eystein; Moros, Matthias; Ogilvie, Astrid E. J.. |
| Satellite data suggest an Arctic sea ice-climate system in rapid transformation, yet its long-term natural modes of variability are poorly known. Here we integrate and synthesize a set of multicentury historical records of Atlantic Arctic sea ice, supplemented with high-resolution paleoproxy records, each reflecting primarily winter/spring sea ice conditions. We establish a signal of pervasive and persistent multidecadal (~60–90 year) fluctuations that is most pronounced in the Greenland Sea and weakens further away. Covariability between sea ice and Atlantic multidecadal variability as represented by the Atlantic Multidecadal Oscillation (AMO) index is evident during the instrumental record, including an abrupt change at the onset of the early twentieth... |
| Tipo: Text |
Palavras-chave: Sea ice. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00291/40199/39229.pdf |
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| Doddridge, Edward W.; Meneghello, Gianluca; Marshall, John; Scott, Jon; Lique, Camille. |
| The Beaufort Gyre (BG) is a large anticyclonic circulation in the Arctic Ocean. Its strength is directly related to the halocline depth, and therefore also to the storage of freshwater. It has recently been proposed that the equilibrium state of the BG is set by the Ice‐Ocean Governor, a negative feedback between surface currents and ice‐ocean stress, rather than a balance between lateral mesoscale eddy fluxes and surface Ekman pumping. However, mesoscale eddies are present in the Arctic Ocean; it is therefore important to extend the Ice‐Ocean Governor theory to include lateral fluxes due to mesoscale eddies. Here, a non‐linear ordinary differential equation is derived that represents the effects of wind stress, the Ice‐Ocean Governor, and eddy fluxes.... |
| Tipo: Text |
Palavras-chave: Beaufort Gyre; Ice-Ocean Governor; Mesoscale eddies; Arctic; Sea ice. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00487/59844/62994.pdf |
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| Wang, Qiang; Ilicak, Mehmet; Gerdes, Ruediger; Drange, Helge; Aksenov, Yevgeny; Bailey, David A.; Bentsen, Mats; Biastoch, Arne; Bozec, Alexandra; Boening, Claus; Cassou, Christophe; Chassignet, Eric; Coward, Andrew C.; Curry, Beth; Danabasoglu, Gokhan; Danilov, Sergey; Fernandez, Elodie; Fogli, Pier Giuseppe; Fujii, Yosuke; Griffies, Stephen M.; Iovino, Doroteaciro; Jahn, Alexandra; Jung, Thomas; Large, William G.; Lee, Craig; Lique, Camille; Lu, Jianhua; Masina, Simona; Nurser, A. J. George; Rabe, Benjamin; Roth, Christina; Salas Y Melia, David; Samuels, Bonita L.; Spence, Paul; Tsujino, Hiroyuki; Valcke, Sophie; Voldoire, Aurore; Wang, Xuezhu; Yeager, Steve G.. |
| The Arctic Ocean simulated in 14 global ocean-sea ice models in the framework of the Coordinated Ocean-ice Reference Experiments, phase II (CORE-II) is analyzed in this study. The focus is on the Arctic liquid freshwater (FW) sources and freshwater content (FWC). The models agree on the interannual variability of liquid FW transport at the gateways where the ocean volume transport determines the FW transport variability. The variation of liquid FWC is induced by both the surface FW flux (associated with sea ice production) and lateral liquid FW transport, which are in phase when averaged on decadal time scales. The liquid FWC shows an increase starting from the mid-1990s, caused by the reduction of both sea ice formation and liquid FW export, with the... |
| Tipo: Text |
Palavras-chave: Arctic Ocean; Freshwater; Sea ice; CORE II atmospheric forcing. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00313/42463/41835.pdf |
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| The Integrated Global Observing Strategy Partnership (IGOS-P) established, in 1999, a thematic approach to the implementation of the IGOS. Recognising that other themes will emerge, the “Ocean Theme” was chosen to be the “pathfinder” in this approach and an Ocean Theme Team was assembled to formulate guidance. One goal of the Ocean Theme Team is to consider and study the full range of current and planned observations, while identifying potential gaps in future observations that might compromise ocean observational records. This document presents a proposed set of long-term ocean observations and identifies a number of challenges for the improvement of knowledge about both the oceans and observing techniques. The overall strategy is to create an observing... |
| Tipo: Conference Material |
Palavras-chave: Oceanography; Wind vectors; Surface temperature; Sea ice. |
| Ano: 2000 |
URL: http://hdl.handle.net/1834/2810 |
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| The Integrated Global Observing Strategy Partnership (IGOS-P) established, in 1999, a thematic approach to the implementation of the IGOS. Recognising that other themes will emerge, the “Ocean Theme” was chosen to be the “pathfinder” in this approach and an Ocean Theme Team was assembled to formulate guidance. One goal of the Ocean Theme Team is to consider and study the full range of current and planned observations, while identifying potential gaps in future observations that might compromise ocean observational records. This document presents a proposed set of long-term ocean observations and identifies a number of challenges for the improvement of knowledge about both the oceans and observing techniques. The overall strategy is to create an observing... |
| Tipo: Proceedings Paper |
Palavras-chave: Oceanography; Surface temperature; Wind vectors; Sea ice; Salinity; Salinity; Http://aims.fao.org/aos/agrovoc/c_6751. |
| Ano: 2000 |
URL: http://hdl.handle.net/1834/2631 |
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| Thomas, Elizabeh R; Allen, Claire S; Etourneau, Johan; King, Amy Cf; Severi, Mirko; Winton, V. Holly L.; Mueller, Juliane; Crosta, Xavier; Peck, Victoria L.. |
| Dramatic changes in sea ice have been observed in both poles in recent decades. However, the observational period for sea ice is short, and the climate models tasked with predicting future change in sea ice struggle to capture the current Antarctic trends. Paleoclimate archives, from marine sedimentary records and coastal Antarctic ice cores, provide a means of understanding sea ice variability and its drivers over decadal to centennial timescales. In this study, we collate published records of Antarctic sea ice over the past 2000 years (2 ka). We evaluate the current proxies and explore the potential of combining marine and ice core records to produce multi-archive reconstructions. Despite identifying 92 sea ice reconstructions, the spatial and temporal... |
| Tipo: Text |
Palavras-chave: Sea ice; Antarctica; Paleoclimate; Ice cores; Marine sediments. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00595/70709/68916.pdf |
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| Muilwijk, Morven; Ilicak, Mehmet; Cornish, Sam B.; Danilov, Sergey; Gelderloos, Renske; Gerdes, Rüdiger; Haid, Verena; Haine, Thomas W.n.; Johnson, Helen L.; Kostov, Yavor; Kovács, Tamás; Lique, Camille; Marson, Juliana M.; Myers, Paul G.; Scott, Jon; Smedsrud, Lars H.; Talandier, Claude; Wang, Qiang. |
| Multi‐model Arctic Ocean ``Climate Response Function” (CRF) experiments are analyzed in order to explore the effects of anomalous wind forcing over the Greenland Sea (GS) on poleward ocean heat transport, Atlantic Water (AW) pathways, and the extent of Arctic sea ice. Particular emphasis is placed on the sensitivity of the AW circulation to anomalously strong or weak GS winds in relation to natural variability, the latter manifested as part of the North Atlantic Oscillation (NAO). We find that anomalously strong (weak) GS wind forcing, comparable in strength to a strong positive (negative) NAO index, results in an intensification (weakening) of the poleward AW flow, extending from south of the North Atlantic Subpolar Gyre, through the Nordic Seas, and all... |
| Tipo: Text |
Palavras-chave: Arctic Ocean; Atlantic Water; Sea ice; Wind forcing; Model intercomparison; FAMOS. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00510/62126/66338.pdf |
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| Ardhuin, Fanny; Ezraty, Robert; Croize-fillon, Denis. |
| Backscatter values from scatterometers are commonly used to estimate wind field over oceans, their ability to monitor sea ice coverage, age and drift has been also demonstrated. Here, ASCAT backscatter coefficient has been processed for sea ice geophysical interpretation in order to increase the long time series of ice parameters already available. It has been shown that incidence- adjustment is mandatory for geophysical meaning, the backscatter maps enable the discrimination between multi year ice and first year ice, these maps can also be used as a basic product for sea ice drift estimation. (Copyright : European Space Agency ISBN 978-92-9221-239-1 ISSN 1609-042X) |
| Tipo: Text |
Palavras-chave: Sea ice; Wind; Scatterometer; ASCAT; MetOp; Glaces de mer; Vent; Diffusiomètre; ASCAT; MetOp. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/acte-6970.pdf |
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| Ortega, J.; Jara, V.; Alvarez, M.; Rentería, W.. |
| El presente estudio consiste en un análisis descriptivo de los parámetros físicos (temperatura-salinidad) y corrientes superficiales y sub-superficiales, obtenidos en los sitios de visita turística de la Reserva Marina de Galápagos (RMG), los cuales describen las condiciones oceanográficas de dichos lugares. Estos datos han sido procesados con el propósito de establecer una caracterización de la temperatura superficial del mar en estos sitios, y sus variaciones a lo largo del 2011. Esta caracterización será soportada con el uso de los datos del Análisis Operacional de Temperatura Superficial del Mar y de Hielo Marino (UKMO-L4HRfnd-GLOB-OSTIA) a fin de conseguir una continuidad en la serie de tiempo anual. |
| Tipo: Journal Contribution |
Palavras-chave: Temperature; Salinity; Surface temperature; Sea ice; Marine parks; Surface currents currents. |
| Ano: 2012 |
URL: http://hdl.handle.net/1834/4658 |
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| Barton, Benjamin I. |
| Winter sea ice has declined in the Barents Sea and there is growing evidence that the low sea ice here coincides with cold, winter surface air temperature in Europe and Asia. Atlantic Water (AW) transported into the Barents Sea is warming and its temperature variability is correlated with variability in sea ice extent. As AW extends into the Barents Sea it is modified into a cooler, fresher water mass called BarentsSea Water (BSW). There are limited observations of BSW despite its importance in the Arctic Ocean system, leading to the question, how does the seasonal sea ice impact ocean stratification and mean flow?First, satellite observations are used to find the Polar Front, a water mass boundary between BSW and fresher Arctic Water to the north. The sea... |
| Tipo: Text |
Palavras-chave: Barents Sea Water; Front polaire; Banquise; Satellite; Modélisation; Model; Barents Sea Water; Polar front; Sea ice; Satellite. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00692/80424/83560.pdf |
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| Nichols, Carol; Lardiere, Sandrine; Bowman, John; Nichols, Peter; Gibson, John; Guezennec, Jean. |
| Exopolysaccharides (EPS) may have an important role in the Antarctic marine environment, possibly acting as ligands for trace metal nutrients such as iron or providing cryoprotection for growth at low temperature and high salinity. Ten bacterial strains, isolated from Southern Ocean particulate material or from sea ice, were characterized. Whole cell fatty acid profiles and 16S rRNA gene sequences showed that the isolates included representatives of the genera Pseudoalteromonas, Shewanella, Polaribacter, and Flavobacterium as well as one strain, which constituted a new bacterial genus in the family Flavobacteriaceae. The isolates are, therefore, members of the "Gammaproteobacteria" and Cytophaga-Flexibacter-Bacteroides, the taxonomic groups that have been... |
| Tipo: Text |
Palavras-chave: Marine particulates; Sea ice; Marine bacteria; Antarctica; Exopolysaccharides. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-623.pdf |
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| Dokken, Trond M.; Nisancioglu, Kerim H.; Li, Camille; Battisti, David S.; Kissel, Catherine. |
| Dansgaard-Oeschger (D-O) cycles are the most dramatic, frequent, and wide-reaching abrupt climate changes in the geologic record. On Greenland, D-O cycles are characterized by an abrupt warming of 105 degrees C from a cold stadial to a warm interstadial phase, followed by gradual cooling before a rapid return to stadial conditions. The mechanisms responsible for these millennial cycles are not fully understood but are widely thought to involve abrupt changes in Atlantic Meridional Overturning Circulation due to freshwater perturbations. Here we present a new, high-resolution multiproxy marine sediment core monitoring changes in the warm Atlantic inflow to the Nordic seas as well as in local sea ice cover and influx of ice-rafted debris. In contrast to... |
| Tipo: Text |
Palavras-chave: D-O cycles; Nordic seas; Marine sediment core; Greenland ice core; Abrupt changes; Sea ice. |
| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00264/37490/35779.pdf |
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| Nichols, Carol; Bowman, John; Guezennec, Jean. |
| The sea ice microbial community plays a key role in the productivity of the Southern Ocean. Exopolysaccharide (EPS) is a major component of the exopolymer secreted by many marine bacteria to enhance survival and is abundant in sea ice brine channels, but little is known about its function there. This study investigated the effects of temperature on EPS production in batch culture by CAM025, a marine bacterium isolated from sea ice sampled from the Southern Ocean. Previous studies have shown that CAM025 is a member of the genus Pseudoalteromonas and therefore belongs to a group found to be abundant in sea ice by culture-dependent and -independent techniques. Batch cultures were grown at -2 degrees C, 10 degrees C, and 20 degrees C, and cell number, optical... |
| Tipo: Text |
Palavras-chave: EPS yield; Psychrotolerant; Sea ice; Marine bacteria; Antarctica; Exopolymer; Exopolysaccharides. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-625.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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| Ardhuin, Fanny; Ezraty, Robert. |
| Satellites enable daily and global coverage of the polar oceans and provide a unique monitoring capability of sea ice dynamics. Sea ice drift maps can be estimated in Arctic from several satellite sensors, particularly from scatterometers and radiometers. This study presents the benefits of combining single drift fields at the same resolution into a "merged" field, built at three-and six-day lags during winters with a 62.5-km resolution. It is shown that combining these drift fields not only increases the reliability of the displacement estimation and the number of estimated vectors to almost a full ice covered area but also expands the time period over which these estimations are reliable from freeze until the melt onset. The autumn-winter-spring sea ice... |
| Tipo: Text |
Palavras-chave: Arctic; Advanced Scatterometer (ASCAT); Drift; Merging; Scatterometry; Sea ice. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00088/19895/17729.pdf |
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| Ardhuin, Fabrice; Collard, Fabrice; Chapron, Bertrand; Ardhuin, Fanny; Guitton, Gilles; Mouche, Alexis; Stopa, Justin. |
| Swell evolution from the open ocean into sea ice is poorly understood, in particular the amplitude attenuation expected from scattering and dissipation. New synthetic aperture radar (SAR) data from Sentinel-1A wave mode reveal intriguing patterns of bright oscillating lines shaped like instant noodles. We investigate cases in which the oscillations are in the azimuth direction, around a straight line in the range direction. This observation is interpreted as the distortion by the SAR processing of crests from a first swell, due to the presence of a second swell. Since deviations from a straight line should be proportional to the orbital velocity toward the satellite, swell height can be estimated, from 1.5 to 5 m in the present case. The evolution of this... |
| Tipo: Text |
Palavras-chave: Ocean waves; SAR; Sea ice. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00256/36718/35332.pdf |
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| Registros recuperados: 52 | |
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