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Registros recuperados: 52 | |
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Lafond, Augustin; Leblanc, Karine; Queguiner, Bernard; Moriceau, Brivaela; Leynaert, Aude; Cornet, Veronique; Legras, Justine; Ras, Josephine; Parenteau, Marie; Garcia, Nicole; Babin, Marcel; Tremblay, Jean-eric. |
The Arctic Ocean is particularly affected by climate change, with changes in sea ice cover expected to impact phytoplankton primary production. During the Green Edge expedition, the development of the late spring-early summer diatom bloom was studied in relation with the sea ice retreat by multiple transects across the marginal ice zone. Biogenic silica concentrations and uptake rates were measured. In addition, diatom assemblage structures and their associated carbon biomass were determined, along with taxon-specific contributions to total biogenic silica production using the fluorescent dye PDMPO. Results indicate that a diatom bloom developed in open waters close to the ice edge, following the alleviation of light limitation, and extended 20-30 km... |
Tipo: Text |
Palavras-chave: Diatoms; Spring bloom; Sea ice; Community composition; Baffin Bay; Arctic. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00615/72752/72021.pdf |
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Lique, Camille. |
While perhaps the most obvious, ice retreat is just one aspect of a changing Arctic system. The Arctic Ocean is also undergoing unprecedented modifications, that mostly affect its heat and freshwater budgets. As the signal of Arctic change is expected to have its major climatic impact by reaching south the subarctic seas, on either side of Greenland, to modulate the Atlantic thermohaline circulation, the objective of this thesis is to investigate the variability of the exports of volume, heat, freshwater and sea-ice from the Arctic Ocean to the North Atlantic. First, a realistic simulation from 1958 to 2002 run with a global ocean/sea-ice model is used to investigate some aspects of the variability of the Arctic freshwater budget, trying to understand... |
Tipo: Text |
Palavras-chave: Océan Arctique; Bilan d'eau douce; Flux d'eau douce; Glace de mer; Modèle numérique - Analyse Lagrangienne - Forçages atmosphériques; Arctic Ocean; Freshwater budget; Freshwater flux; Sea ice; Numerical model; Lagrangian analysis; Atmospheric forcing. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00015/12597/9474.pdf |
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Belt, Simon T.; Mueller, Juliane. |
In recent years, a novel proxy for the past occurrence of Arctic sea ice has been proposed that is based on the variable marine sedimentary abundance of an organic geochemical lipid derived from sea ice diatoms in the spring. This lipid, termed IP25 (Ice Proxy with 25 carbon atoms), is a highly branched isoprenoid mono-unsaturated alkene that appears to be sufficiently stable in sediments to permit meaningful palaeo sea ice reconstructions to be carried out over short- to long-term timescales. Since the first proposed use of IP25 as a proxy for palaeo sea ice by Belt et al. (2007), a number of laboratories have measured this biomarker in Arctic sediments and it is anticipated that research activity in this area will increase further in the future. The... |
Tipo: Text |
Palavras-chave: Sea ice; Arctic; Proxy; IP25; Biomarker; Palaeoclimate. |
Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00263/37473/36537.pdf |
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Smith, Gregory C.; Allard, Richard; Babin, Marcel; Bertino, Laurent; Chevallier, Matthieu; Corlett, Gary; Crout, Julia; Davidson, Fraser; Delille, Bruno; Gille, Sarah T.; Hebert, David; Hyder, Patrick; Intrieri, Janet; Lagunas, Jose; Larnicol, Gilles; Kaminski, Thomas; Kater, Belinda; Kauker, Frank; Marec, Claudie; Mazloff, Matthew; Metzger, E. Joseph; Mordy, Calvin; O'Carroll, Anne; Olsen, Steffen M.; Phelps, Michael; Posey, Pamela; Prandi, Pierre; Rehm, Eric; Reid, Phillip; Rigor, Ignatius; Sandven, Stein; Shupe, Matthew; Swart, Sebastiaan; Smedstad, Ole Martin; Solomon, Amy; Storto, Andrea; Thibaut, Pierre; Toole, John; Wood, Kevin; Xie, Jiping; Yang, Qinghua. |
There is a growing need for operational oceanographic predictions in both the Arctic and Antarctic polar regions. In the former, this is driven by a declining ice cover accompanied by an increase in maritime traffic and exploitation of marine resources. Oceanographic predictions in the Antarctic are also important, both to support Antarctic operations and also to help elucidate processes governing sea ice and ice shelf stability. However, a significant gap exists in the ocean observing system in polar regions, compared to most areas of the global ocean, hindering the reliability of ocean and sea ice forecasts. This gap can also be seen from the spread in ocean and sea ice reanalyses for polar regions which provide an estimate of their uncertainty. The... |
Tipo: Text |
Palavras-chave: Polar observations; Operational oceanography; Ocean data assimilation; Ocean modeling; Forecasting; Sea ice; Air-sea-ice fluxes; YOPP. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00512/62379/66650.pdf |
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Stoffelen, Ad; Aaboe, Signe; Calvet, Jean-christophe; Cotton, James; De Chiara, Giovanna; Saldana, Julia Figa; Mouche, Alexis; Portabella, Marcos; Scipal, Klaus; Wagner, Wolfgang. |
The second-generation exploitation of meteorological satellite polar system (EPS-SG) C-band-wavelength scatterometer instrument (called SCA), planned for launch in 2022, has a direct heritage from the successful advanced scatterometer (ASCAT) flown on the current EPS satellites. In addition, SCA will represent three major innovations with respect to ASCAT, namely: 1) Cross polarization and horizontal copolarization; 2) a nominal spatial resolution of 25 km; and 3) 20% greater spatial coverage than ASCAT. The associated expected science and application benefits that led the SCA design are discussed with respect to ocean, land, and sea ice applications for near-real time, climate monitoring, and research purposes. Moreover, an option to implement an ocean... |
Tipo: Text |
Palavras-chave: Eddy currents; Radar signal processing; Sea ice; Soil measurements; Storms; Wind. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00386/49774/50320.pdf |
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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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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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Sadatzki, Henrik; Maffezzoli, Niccolò; Dokken, Trond M.; Simon, Margit H; Berben, Sarah M. P.; Fahl, Kirsten; Kjær, Helle A.; Spolaor, Andrea; Stein, Ruediger; Vallelonga, Paul; Vinther, Bo M.; Jansen, Eystein. |
Constraining the past sea ice variability in the Nordic Seas is critical for a comprehensive understanding of the abrupt Dansgaard-Oeschger (D-O) climate changes during the last glacial. Here we present unprecedentedly detailed sea ice proxy evidence from two Norwegian Sea sediment cores and an East Greenland ice core to resolve and constrain sea ice variations during four D-O events between 32 and 41 ka. Our independent sea ice records consistently reveal a millennial-scale variability and threshold response between an extensive seasonal sea ice cover in the Nordic Seas during cold stadials and reduced seasonal sea ice conditions during warmer interstadials. They document substantial and rapid sea ice reductions that may have happened within 250 y or... |
Tipo: Text |
Palavras-chave: Sea ice; Nordic Seas; Dansgaard-Oeschger events; Abrupt climate change. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00659/77066/78374.pdf |
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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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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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Dash, Prasanjit; Ignatov, Alexander; Martin, Matthew; Donlon, Craig; Brasnett, Bruce; Reynolds, Richard W.; Banzon, Viva; Beggs, Helen; Cayula, Jean-francois; Chao, Yi; Grumbine, Robert; Maturi, Eileen; Harris, Andy; Mittaz, Jonathan; Sapper, John; Chin, Toshio M.; Vazquez-cuervo, Jorge; Armstrong, Edward M.; Gentemann, Chelle; Cummings, James; Piolle, Jean-francois; Autret, Emmanuelle; Roberts-jones, Jonah; Ishizaki, Shiro; Hoyer, Jacob L.; Poulter, Dave. |
There are a growing number of level 4 (L4; gap-free gridded) sea surface temperature (SST) products generated by blending SST data from various sources which are available for use in a wide variety of operational and scientific applications. In most cases, each product has been developed for a specific user community with specific requirements guiding the design of the product. Consequently differences between products are implicit. In addition, anomalous atmospheric conditions, satellite operations and production anomalies may occur which can introduce additional differences. This paper describes a new web-based system called the L4 SST Quality Monitor (L4-SQUAM) developed to monitor the quality of L4 SST products. L4-SQUAM intercompares thirteen L4... |
Tipo: Text |
Palavras-chave: Sea surface temperature; Intercomparison; Climate data; Sea ice; Data centers. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00101/21188/19798.pdf |
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Arndt, Stefanie; Meiners, Klaus M.; Ricker, Robert; Krumpen, Thomas; Katlein, Christian; Nicolaus, Marcel. |
Snow on sea ice alters the properties of the underlying ice cover as well as associated physical and biological processes at the interfaces between atmosphere, sea ice, and ocean. The Antarctic snow cover persists during most of the year and contributes significantly to the sea-ice mass due to the widespread surface flooding and related snow-ice formation. Snow also enhances the sea-ice surface reflectivity of incoming shortwave radiation and determines therefore the amount of light being reflected, absorbed, and transmitted to the upper ocean. Here, we present results of a case study of spectral solar radiation measurements under Antarctic pack ice with an instrumented Remotely Operated Vehicle in the Weddell Sea in 2013. In order to identify the key... |
Tipo: Text |
Palavras-chave: Light transmittance; Sea ice; Antarctic; Surface flooding; Snow; Shortwave radiation. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00386/49758/50279.pdf |
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Wang, Kun-shan; Shi, Xue-fa; Zou, Jian-jun; Kandasamy, Selvaraj; Gong, Xun; Wu, Yong-hua; Yan, Quan-shu. |
In this study, we investigate light and heavy minerals in sediment core OS03-1 located at the Academy of Sciences Rise of the southern Okhotsk Sea to determine their distributions and sources over the last 180 ka (thousand years). The sediment mainly consists of terrigenous and volcanic detritus. Ubiquitous drop-stones and volcanic detritus throughout the core and high detrital input suggest that sea ice, driven by wind and Kamchatka Current, was the main transport agent of detrital materials to the southern Okhotsk Sea. The ternary diagram of heavy minerals (hornblende-hypersthene-epidote) shows an expansion of detritus provenance from the eastern in cold periods to the northeastern in warm intervals of the Okhotsk Sea. It mainly relates to the shift of... |
Tipo: Text |
Palavras-chave: Light and heavy minerals; Volcanic detrital; Sediment provenance; Sea ice; Okhotsk Sea. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53145/55348.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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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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Carr, Magda; Sutherland, Peter; Haase, Andrea; Evers, Karl‐ulrich; Fer, Ilker; Jensen, Atle; Kalisch, Henrik; Berntsen, Jarle; Părău, Emilian; Thiem, Øyvind; Davies, Peter. |
Internal solitary waves (ISWs) propagating in a stably stratified two-layer fluid in which the upper boundary condition changes from open water to ice are studied for grease, level, and nilas ice. The ISW-induced current at the surface is capable of transporting the ice in the horizontal direction. In the level ice case, the transport speed of, relatively long ice floes, nondimensionalized by the wave speed is linearly dependent on the length of the ice floe nondimensionalized by the wave length. Measures of turbulent kinetic energy dissipation under the ice are comparable to those at the wave density interface. Moreover, in cases where the ice floe protrudes into the pycnocline, interaction with the ice edge can cause the ISW to break or even be destroyed... |
Tipo: Text |
Palavras-chave: Internal solitary waves; Sea ice; Arctic Ocean. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00593/70532/68677.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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Registros recuperados: 52 | |
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