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| Registros recuperados: 34 | |
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| Treguier, Anne-marie; Lique, Camille; Deshayes, Julie; Molines, J. M.. |
| Correlations between temperature and velocity fluctuations are a significant contribution to the North Atlantic meridional heat transport, especially at the northern boundary of the subtropical gyre. In satellite observations and in a numerical model at 1/12 degrees resolution, a localized pattern of positive eddy heat flux is found northwest of the Gulf Stream, downstream of its separation at Cape Hatteras. It is confined to the upper 500 m. A simple kinematic model of a meandering jet can explain the surface eddy flux, taking into account a spatial shift between the maximum velocity of the jet and the maximum cross-jet temperature gradient. In the Gulf Stream such a spatial shift results from the nonlinear temperature profile and the vertical tilting of... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00391/50247/50871.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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| 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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| Lemieux, Jean-francois; Lei, Ji; Dupont, Frederic; Roy, Francois; Losch, Martin; Lique, Camille; Laliberte, Frederic. |
| The impact of tides on the simulated landfast ice cover is investigated. Pan‐Arctic simulations are conducted with an ice‐ocean (CICE‐NEMO) model with a modified rheology and a grounding scheme. The reference experiment (without tides) indicates there is an overestimation of the extent of landfast ice in regions of strong tides such as the Gulf of Boothia, Prince Regent Inlet and Lancaster Sound. The addition of tides in the simulation clearly leads to a decrease of the extent of landfast ice in some tidally active regions. This numerical experiment with tides is more in line with observations of landfast ice in all the regions studied. Thermodynamics and changes in grounding cannot explain the lower landfast ice area when tidal forcing is included. We... |
| Tipo: Text |
Palavras-chave: Landfast ice; Tides; Ice-ocean model. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00460/57132/59053.pdf |
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| Zhang, Yurui; Huck, Thierry; Lique, Camille; Donnadieu, Yannick; Ladant, Jean-baptiste; Rabineau, Marina; Aslanian, Daniel. |
| The early Eocene (∼55 Ma) was the warmest period of the Cenozoic and was most likely characterized by extremely high atmospheric CO2 concentrations. Here, we analyze simulations of the early Eocene performed with the IPSL-CM5A2 Earth system model, set up with paleogeographic reconstructions of this period from the DeepMIP project and with different levels of atmospheric CO2. When compared with proxy-based reconstructions, the simulations reasonably capture both the reconstructed amplitude and pattern of early Eocene sea surface temperature. A comparison with simulations of modern conditions allows us to explore the changes in ocean circulation and the resulting ocean meridional heat transport. At a CO2 level of 840 ppm, the early Eocene simulation is... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75529/76436.pdf |
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| Regan, Heather; Lique, Camille; Armitage, Thomas W. K.. |
| The Beaufort Gyre is a significant reservoir of freshwater in the Arctic. It is thought to play a key role in regulating Arctic freshwater discharge to the North Atlantic, and in recent decades its freshwater content has increased in a time of rapid Arctic change. Despite this, its exact dynamical behaviour is not fully understood. Here, we make use of an Arctic‐wide dataset of Dynamic Ocean Topography (DOT), including data under sea ice, to characterise the time‐varying extent, shape, and location of the Beaufort Gyre. We show that the gyre expanded towards the north‐west between 2003 and 2014, resulting in increased proximity to the Chukchi Plateau and Mendeleev Ridge by 2014. We find that the gyre strength and maximum DOT both respond readily to changes... |
| Tipo: Text |
Palavras-chave: Arctic oceanography; Beaufort Gyre; Dynamic ocean topography; Freshwater. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00476/58763/61302.pdf |
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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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| Carmack, E. C.; Yamamoto-kawai, M.; Haine, T. W. N.; Bacon, S.; Bluhm, B. A.; Lique, Camille; Melling, H.; Polyakov, I. V.; Straneo, F.; Timmermans, M. -l.; Williams, W. J.. |
| The Arctic Ocean is a fundamental node in the global hydrological cycle and the ocean's thermohaline circulation. We here assess the system's key functions and processes: 1) the delivery of fresh and low salinity waters to the Arctic Ocean by river inflow, net precipitation, distillation during the freeze/thaw cycle and Pacific Ocean inflows; 2) the disposition (e.g. sources, pathways and storage) of freshwater components within the Arctic Ocean; and 3) the release and export of freshwater components into the bordering convective domains of the North Atlantic. We then examine physical, chemical or biological processes which are influenced or constrained by the local quantities and geochemical qualities of fresh water; these include: stratification and... |
| Tipo: Text |
Palavras-chave: Arctic; Oceans; Circulation; Freshwater; Carbon cycle; Acidification. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00313/42460/41831.pdf |
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| Lique, Camille; Treguier, Anne-marie; Blanke, Bruno; Grima, Nicolas. |
| The origin of the water masses exported from the Arctic to the North Atlantic along both sides of Greenland is investigated using an original numerical method. A quantitative Lagrangian analysis is applied to the monthly climatological 3-D output of a global ocean/sea ice high-resolution model. It allows quantification of the different branches of the export to the North Atlantic, as well as related timescales and water mass transformations. In the model, the outflow through Davis Strait consists in equal parts of Pacific and Atlantic water, whilst the export through Fram Strait consists almost fully of Atlantic water (contrary to observations). Pacific water is transferred quickly (O(10 years)) to the North Atlantic through the Beaufort Gyre, where... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00005/11591/8232.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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| Treguier, Anne-marie; Deshayes, Julie; Le Sommer, Julien; Lique, Camille; Madec, G.; Penduff, Thierry; Molines, Jean-marc; Barnier, Bernard; Bourdalle-badie, Romain; Talandier, Claude. |
| The meridional transport of salt is computed in a global eddy-resolving numerical model (1/12 degrees resolution) in order to improve our understanding of the ocean salinity budget. A methodology is proposed that allows a global analysis of the salinity balance in relation to surface water fluxes, without defining a "freshwater anomaly" based on an arbitrary reference salinity. The method consists of a decomposition of the meridional transport into (i) the transport by the time-longitude-depth mean velocity, (ii) time-mean velocity recirculations and (iii) transient eddy perturbations. Water is added (rainfall and rivers) or removed (evaporation) at the ocean surface at different latitudes, which creates convergences and divergences of mass transport with... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00192/30319/28790.pdf |
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| Lique, Camille; Johnson, Helen L.; Plancherel, Yves. |
| The appearance of winter deep mixed layers in the Arctic Ocean under a warming climate is investigated with the HiGEM coupled global climate model. In response to a four times increase of atmospheric CO2 levels with respect to present day conditions, the Arctic Basin becomes seasonally ice-free. Its surface becomes consequently warmer and, on average, slightly fresher. Locally, changes in surface salinity can be far larger (up to 4 psu) than the basin-scale average, and of a different sign. The Canadian Basin undergoes a strong freshening, while the Eurasian Basin undergoes strong salinification. These changes are driven by the spin up of the surface circulation, likely resulting from the increased transfer of momentum to the ocean as sea ice cover is... |
| Tipo: Text |
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| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00395/50609/51451.pdf |
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| Barton, Benjamin I.; Lique, Camille; Lenn, Yueng‐djern. |
| The Barents Sea is a region of deep water formation where Atlantic Water is converted into cooler, fresher Barents Sea Water. Barents Sea Water properties exhibit variability at seasonal, interannual and decadal timescales. This variability is transferred to Arctic Intermediate Water, which eventually contributes to the deeper branch of the Atlantic Meridional Overturning Circulation. Variations in Barents Sea Water properties are reflected in steric height (contribution of density to sea level variations) that depends on heat and freshwater content, and is a quantity usually derived from in situ observations of water temperature, salinity and pressure that remain sparse during winter in the Barents Sea. This analysis explores the utility of satellite... |
| Tipo: Text |
Palavras-chave: Satellite; Steric height; Freshwater content; Heat content; Arctic Ocean. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00634/74651/74556.pdf |
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| Registros recuperados: 34 | |
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