Consulta: creatorFacets:"Lique, Camille"
Registros recuperados: 34
Data/hora: 09/06/2024 14:36:31

Locations and mechanisms of ocean ventilation in the high-latitude North Atlantic in an eddy-permitting ocean model
Provedor de dados: 5
Autores: Macgilchrist, Graeme A.; Johnson, Helen L.; Marshall, David P.; Lique, Camille; Thomas, Matthew; Jackson, Laura C.; Wood, Richard A.
A substantial fraction of the deep ocean is ventilated in the high-latitude North Atlantic. Consequently, the region plays a crucial role in transient climate change through the uptake of carbon dioxide and heat. However, owing to the Lagrangian nature of the process, many aspects of deep Atlantic Ocean ventilation and its representation in climate simulations remain obscure. We investigate the nature of ventilation in the high latitude North Atlantic in an eddy-permitting numerical ocean circulation model using a comprehensive set of Lagrangian trajectory experiments. Backwards-in-time trajectories from a model-defined ‘North Atlantic DeepWater’ (NADW) reveal the locations of subduction from the surface mixed layer at high spatial resolution. The major...
Tipo: Text
Palavras-chave: North Atlantic Ocean; Atmosphere-ocean interaction; Lagrangian circulation/transport; Ocean circulation; Boundary currents; Diapycnal mixing.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00646/75833/76825.pdf

SKIM, a Candidate Satellite Mission Exploring Global Ocean Currents and Waves
Provedor de dados: 5
Autores: Ardhuin, Fabrice; Brandt, Peter; Gaultier, Lucile; Donlon, Craig; Battaglia, Alessandro; Boy, François; Casal, Tania; Chapron, Bertrand; Collard, Fabrice; Cravatte, Sophie; Delouis, Jean Marc; De Witte, Erik; Dibarboure, Gerald; Engen, Geir; Johnsen, Harald; Lique, Camille; Lopez-dekker, Paco; Maes, Christophe; Martin, Adrien; Marié, Louis; Menemenlis, Dimitris; Nouguier, Frederic; Peureux, Charles; Rampal, Pierre; Ressler, Gerhard; Rio, Marie-helene; Rommen, Bjorn; Shutler, Jamie D.; Suess, Martin; Tsamados, Michel; Ubelmann, Clement; Van Sebille, Erik; Van Den Oever, Martin; Stammer, Detlef.
The Sea surface KInematics Multiscale monitoring (SKIM) satellite mission is designed to explore ocean surface current and waves. This includes tropical currents, notably the poorly known patterns of divergence and their impact on the ocean heat budget, and monitoring of the emerging Arctic up to 82.5°N. SKIM will also make unprecedented direct measurements of strong currents, from boundary currents to the Antarctic circumpolar current, and their interaction with ocean waves with expected impacts on air-sea fluxes and extreme waves. For the first time, SKIM will directly measure the ocean surface current vector from space. The main instrument on SKIM is a Ka-band conically scanning, multi-beam Doppler radar altimeter/wave scatterometer that includes a...
Tipo: Text
Palavras-chave: Ocean current; Tropics; Arctic; Doppler; Altimetry; Sea state; Remote sensing; Ocean waves.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00498/60964/64372.pdf

Response of Total and Eddy Kinetic Energy to the recent spin up of the Beaufort Gyre
Provedor de dados: 5
Autores: Regan, Heather; Lique, Camille; Talandier, Claude; Meneghello, Gianluca.
The Beaufort Gyre in the Arctic Ocean has spun up over the past two decades in response to changes of the wind forcing and sea ice conditions, accumulating a significant amount of freshwater. Here a simulation performed with a high-resolution, eddy resolving model is analyzed in order to provide a detailed description of the total and eddy kinetic energy, and their response to this spin up of the gyre. On average, and in contrast to the typical open ocean conditions, the levels of mean and eddy kinetic energy are of the same order of magnitude, and the eddy kinetic energy is only intensified along the boundary and in the subsurface. In response to the strong anomalous atmospheric conditions in 2007, the gyre spins up and the mean kinetic energy almost...
Tipo: Text
Palavras-chave: Ocean; Arctic; Eddies; Ocean dynamics; Ocean models.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00598/71015/69288.pdf

A model-based study of ice and freshwater transport variability along both sides of Greenland
Provedor de dados: 5
Autores: Lique, Camille; Treguier, Anne-marie; Scheinert, Markus; Penduff, Thierry.
We investigate some aspects of the variability of the Arctic freshwater content during the 1965-2002 period using the DRAKKAR eddy admitting global ocean/sea-ice model (12 km resolution in the Arctic). A comparison with recent mooring sections shows that the model realistically represents the major advective exchanges with the Arctic basin, through Bering, Fram and Davis Straits, and the Barents Sea. This allows the separate contributions of the inflows and outflows across each section to be quantified. In the model, the Arctic freshwater content variability is explained by the sea-ice flux at Fram and the combined variations of ocean freshwater inflow (at Bering) and outflow (at Fram and Davis). At all routes, except trough Fram Strait, the freshwater...
Tipo: Text
Palavras-chave: Fram Strait; Davis Strait; Freshwater flux; Freshwater budget; Arctic Ocean.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6713.pdf

Is there any imprint of the wind variability on the Atlantic Water circulation within the Arctic Basin?
Provedor de dados: 5
Autores: Lique, Camille; Johnson, Helen L.
The Atlantic Water (AW) layer in the Arctic Basin is isolated from the atmosphere by the overlaying surface layer, yet observations have revealed that the velocities in this layer exhibit significant variations. Here analysis of a global ocean/sea ice model hindcast, complemented by experiments performed with an idealized process model, is used to investigate what controls the variability of AW circulation, with a focus on the role of wind forcing. The AW circulation carries the imprint of wind variations, both remotely over the Nordic and Barents Seas where they force the AW inflow variability, and locally over the Arctic Basin through the forcing of the wind-driven Beaufort Gyre, which modulates and transfers the wind variability to the AW layer. The...
Tipo: Text
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00313/42420/41755.pdf

Generation of sub-surface anticyclones at Arctic surface fronts due to a surface stress
Provedor de dados: 5
Autores: Brannigan, Liam; Johnson, Helen; Lique, Camille; Nycander, Jonas; Nilsson, Johan.
Isolated anticyclones are frequently observed below the mixed layer in the Arctic Ocean. Some of these sub-surface anticyclones are thought to originate at surface fronts. However, previous idealized simulations with no surface stress show that only cyclone-anticyclone dipoles can propagate away from baroclinically unstable surface fronts. Numerical simulations of fronts subject to a surface stress presented here show that a surface stress in the same direction as the geostrophic flow inhibits dipole propagation away from the front. On the other hand, a surface stress in the opposite direction to the geostrophic flow helps dipoles to propagate away from the front. Regardless of the surface stress at the point of dipole formation, these dipoles can be...
Tipo: Text
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00396/50763/51476.pdf

Lagrangian ocean analysis: fundamentals and practices
Provedor de dados: 5
Autores: Van Sebille, Erik; Griffies, Stephen M.; Abernathey, Ryan; Adams, Thomas P.; Berloff, Pavel; Biastoch, Arne; Blanke, Bruno; Chassignet, Eric P.; Cheng, Yu; Cotter, Colin J.; Deleersnijder, Eric; Doos, Kristofer; Drake, Henri F.; Drijfhout, Sybren; Gary, Stefan F.; Heemink, Arnold W.; Kjellsson, Joakim; Koszalka, Inga Monika; Lange, Michael; Lique, Camille; Macgilchrist, Graeme A.; Marsh, Robert; Adame, C. Gabriela Mayorga; Mcadam, Ronan; Nencioli, Francesco; Paris, Claire B.; Piggott, Matthew D.; Polton, Jeff A.; Ruehs, Siren; Shah, Syed H. A. M.; Thomas, Matthew; Wang, Jinbo; Wolfram, Phillip J.; Zanna, Laure; Zika, Jan D.
Lagrangian analysis is a powerful way to analyse the output of ocean circulation models and other ocean velocity data such as from altimetry. In the Lagrangian approach, large sets of virtual particles are integrated within the three-dimensional, time-evolving velocity fields. Over several decades, a variety of tools and methods for this purpose have emerged. Here, we review the state of the art in the field of Lagrangian analysis of ocean velocity data, starting from a fundamental kinematic framework and with a focus on large-scale open ocean applications. Beyond the use of explicit velocity fields, we consider the influence of unresolved physics and dynamics on particle trajectories. We comprehensively list and discuss the tools currently available for...
Tipo: Text
Palavras-chave: Ocean circulation; Lagrangian analysis; Connectivity; Particle tracking; Future modelling.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00412/52324/53099.pdf

Response of Arctic Freshwater to the Arctic Oscillation in Coupled Climate Models
Provedor de dados: 5
Autores: Cornish, Sam B.; Kostov, Yavor; Johnson, Helen L.; Lique, Camille.
The freshwater content (FWC) of the Arctic Ocean is intimately linked to the stratification—a physical characteristic of the Arctic Ocean with wide relevance for climate and biology. Here, we explore the relationship between atmospheric circulation and Arctic FWC across 12 different Coupled Model Intercomparison Project Phase 5 control run simulations. Using multiple lagged regression, we seek to isolate the linear response of Arctic FWC to a step change in the strength of the Arctic Oscillation (AO), as well as the second and third orthogonal modes of SLP variability over the Arctic domain. There is broad agreement amongst models that a step change to a more anticyclonic AO leads to an increase in Arctic FWC, with an e-folding timescale of five to ten...
Tipo: Text
Palavras-chave: Arctic; Arctic Oscillation; Freshwater; Statistical techniques; Regression.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00601/71270/69668.pdf

Evolution of the Arctic Ocean Salinity, 2007-08: Contrast between the Canadian and the Eurasian Basins
Provedor de dados: 5
Autores: Lique, Camille; Garric, Gilles; Treguier, Anne-marie; Barnier, Bernard; Ferry, Nicolas; Testut, Charles-emmanuel; Ardhuin, Fanny.
The authors investigate the variability of salinity in the Arctic Ocean and in the Nordic and Labrador Seas over recent years to see how the freshwater balance in the Arctic and the exchanges with the North Atlantic have been affected by the recent important sea ice melting, especially during the 2007 sea ice extent minimum. The Global Ocean Reanalysis and Simulations (GLORYS1) global ocean reanalysis based on a global coupled ocean sea ice model with an average of 12-km grid resolution in the Arctic Ocean is used in this regard. Although no sea ice data and no data under sea ice are assimilated, simulation over the 2001-09 period is shown to represent fairly well the 2007 sea ice event and the different components accounting for the ocean and sea ice...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00035/14637/11946.pdf

Modeling the Arctic Freshwater System and its integration in the global system: Lessons learned and future challenges
Provedor de dados: 5
Autores: Lique, Camille; Holland, Marika M.; Dibike, Yonas B.; Lawrence, David M.; Screen, James A.
Numerous components of the Arctic freshwater system (atmosphere, ocean, cryosphere, terrestrial hydrology) have experienced large changes over the past few decades, and these changes are projected to amplify further in the future. Observations are particularly sparse, both in time and space, in the Polar Regions. Hence, modeling systems have been widely used and are a powerful tool to gain understanding on the functioning of the Arctic freshwater system and its integration within the global Earth system and climate. Here, we present a review of modeling studies addressing some aspect of the Arctic freshwater system. Through illustrative examples, we point out the value of using a hierarchy of models with increasing complexity and component interactions, in...
Tipo: Text
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00313/42461/41832.pdf

Towards a coupled model to investigate wave-sea ice interactions in the Arctic marginal ice zone
Provedor de dados: 5
Autores: Boutin, Guillaume; Lique, Camille; Ardhuin, Fabrice; Rousset, Clément; Talandier, Claude; Accensi, Mickael; Girard Ardhuin, Fanny.
The Arctic Marginal Ice Zone (MIZ), where strong interactions between sea ice, ocean and atmosphere are taking place, is expanding as the result of the on-going sea ice retreat. Yet, state-of-art models are not capturing the complexity of the varied processes occurring in the MIZ, and in particular the processes involved in the ocean-sea ice interactions. In the present study, a coupled sea ice - wave model is developed, in order to improve our understanding and model representation of those interactions. The coupling allows us to account for the wave radiative stress resulting from the wave attenuation by sea ice, and the sea ice lateral melt resulting from the wave-induced sea ice break-up. We found that, locally in the MIZ, the waves can affect the sea...
Tipo: Text
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00601/71283/69690.pdf

Characterizing the chaotic nature of ocean ventilation
Provedor de dados: 5
Autores: Macgilchrist, Graeme A.; Marshall, David P.; Johnson, Helen L.; Lique, Camille; Thomas, Matthew.
Ventilation of the upper ocean plays an important role in climate variability on interannual to decadal timescales by influencing the exchange of heat and carbon dioxide between the atmosphere and ocean. The turbulent nature of ocean circulation, manifest in a vigorous mesoscale eddy field, means that pathways of ventilation, once thought to be quasi-laminar, are in fact highly chaotic. We characterize the chaotic nature of ventilation pathways according to a nondimensional filamentation number, which estimates the reduction in filament width of a ventilated fluid parcel due to mesoscale strain. In the subtropical North Atlantic of an eddy-permitting ocean model, the filamentation number is large everywhere across three upper ocean density...
Tipo: Text
Palavras-chave: Ventilation; North Atlantic; Thermocline; Chaos; Mesoscale eddies; Lagrangian trajectories.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00410/52104/52807.pdf

Etude des échanges entre l’Océan Arctique et l’Atlantique Nord : Origine, Variabilité et Impact sur les mers Nordiques
Provedor de dados: 5
Autores: 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

Composition of freshwater in the spring of 2014 on the southern Labrador shelf and slope
Provedor de dados: 5
Autores: Benetti, M.; Reverdin, G.; Lique, Camille; Yashayaev, I.; Holliday, N. P.; Tynan, E.; Torres-valdes, S.; Lherminier, Pascale; Treguer, P.; Sarthou, G.
The Labrador Current is an important conduit of freshwater from the Arctic to the interior North Atlantic subpolar gyre. Here, we investigate the spatial variability of the freshwater sources over the southern Labrador shelf and slope during May-June 2014. Using measurements of seawater properties such as temperature, salinity, nutrients and oxygen isotopic composition, we estimate the respective contributions of saline water of Atlantic and Pacific origins, of brines released during sea ice formation, and of freshwater from sea ice melt and meteoric water origins. On the southern Labrador shelf, we find a large brine signal and Pacific Water influence indicating a large contribution of water from the Canadian Arctic. The brine signal implies that more...
Tipo: Text
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00365/47667/47778.pdf

A Three‐way Balance in The Beaufort Gyre: The Ice‐Ocean Governor, Wind Stress, and Eddy Diffusivity
Provedor de dados: 5
Autores: 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

An assessment of the Arctic Ocean in a suite of interannual CORE-II simulations. Part III: Hydrography and fluxes
Provedor de dados: 5
Autores: Ilicak, Mehmet; Drange, Helge; Wang, Qiang; Gerdes, Rudiger; Aksenov, Yevgeny; Bailey, David; 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; Roth, Christina; Salas Y Melia, David; Samuels, Bonita L.; Spence, Paul; Tsujino, Hiroyuki; Valcke, Sophie; Voldoire, Aurore; Wang, Xuezhu; Yeager, Steve G.
In this paper we compare the simulated Arctic Ocean in 15 global ocean–sea ice models in the framework of the Coordinated Ocean-ice Reference Experiments, phase II (CORE-II). Most of these models are the ocean and sea-ice components of the coupled climate models used in the Coupled Model Intercomparison Project Phase 5 (CMIP5) experiments. We mainly focus on the hydrography of the Arctic interior, the state of Atlantic Water layer and heat and volume transports at the gateways of the Davis Strait, the Bering Strait, the Fram Strait and the Barents Sea Opening. We found that there is a large spread in temperature in the Arctic Ocean between the models, and generally large differences compared to the observed temperature at intermediate depths. Warm bias...
Tipo: Text
Palavras-chave: Arctic Ocean; Atlantic Water; St. Anna Trough; Density currents; CORE-II atmospheric forcing.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00317/42864/42295.pdf

Observed atlantification of the Barents Sea causes the Polar Front to limit the expansion of winter sea ice
Provedor de dados: 5
Autores: Barton, Benjamin I.; Lenn, Yueng-djern; Lique, Camille.
Barents Sea Water (BSW) is formed from Atlantic Water that is cooled through atmospheric heat loss and freshened through seasonal sea ice melt. In the eastern Barents Sea, the BSW and fresher, colder Arctic Water meet at the surface along the Polar Front (PF). Despite its importance in setting the northern limit of BSW ventilation, the PF has been poorly-documented, mostly eluding detection by observational surveys that avoid seasonal sea ice. In this study, satellite sea surface temperature (SST) observations are used in addition to a temperature and salinity climatology to examine the location and structure of the PF, and characterise its variability over the period 1985 – 2016. It is shown that the PF is independent of the position of the sea ice edge...
Tipo: Text
Palavras-chave: Arctic; Sea ice; Fronts; Sea surface temperature; Satellite observations.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00448/56003/57509.pdf

Heat balance in the Nordic Seas in a global 1/12° coupled model
Provedor de dados: 5
Autores: Treguier, Anne-marie; Mathiot, Pierre; Graham, Tim; Copsey, Dan; Lique, Camille; Sterlin, Jean.
The Nordic Seas are a gateway to the Arctic Ocean, where Atlantic water undergoes a strong cooling during its transit. Here we investigate the heat balance of these regions in the high resolution Met Office Global Coupled Model GC3 with a 1/12_ grid. The GC3 model reproduces resolution Met Office Global Coupled Model GC3 with a 1/12_ grid. The GC3 model reproduces the contrasted ice conditions and ocean heat loss between the eastern and western regions of the Nordic Seas. In the west (Greenland and Iceland seas), the heat loss experienced by the ocean is stronger than the atmospheric heat gain, because of the cooling by ice melt. The latter is a major contribution to the heat loss over the path of the East Greenland Current and west of Svalbard. In the...
Tipo: Text
Palavras-chave: Arctic; Atmosphere-ocean interaction; Ocean dynamics; Eddies; Climate models; Oceanic variability.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00654/76590/77739.pdf

Eddy contributions to the meridional transport of salt in the North Atlantic
Provedor de dados: 5
Autores: Treguier, Anne-marie; Deshayes, Julie; Lique, Camille; Dussin, Raphael; Molines, Jean-marc.
The meridional transport of salt in the Atlantic ocean is an important process for climate, controlling the stability of the meridional overturning circulation. The contribution of transient eddies to this transport is quantified in an eddy resolving North Atlantic model at 1/12 degrees resolution (NATL12), and compared with lower resolution North-Atlantic and global 1/4 degrees models. In NATL12 between 10 degrees N and 40 degrees N, there is a volume loss by evaporation of 0.6 Sverdrups (Sv). The divergence of the eddy flux of salt (normalized by a reference salinity of 34.8) is 0.2 Sv over the region, a significant fraction of the total air-seawater exchange, but it is compensated by an opposite convergent transport of salt by the mean flow, so that the...
Tipo: Text
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00083/19441/17052.pdf

Wave–sea-ice interactions in a brittle rheological framework
Provedor de dados: 5
Autores: Boutin, Guillaume; Williams, Timothy; Rampal, Pierre; Olason, Einar; Lique, Camille.
As sea ice extent decreases in the Arctic, surface ocean waves have more time and space to develop and grow, exposing the marginal ice zone (MIZ) to more frequent and more energetic wave events. Waves can fragment the ice cover over tens of kilometres, and the prospect of increasing wave activity has sparked recent interest in the interactions between wave-induced sea ice fragmentation and lateral melting. The impact of this fragmentation on sea ice dynamics, however, remains mostly unknown, although it is thought that fragmented sea ice experiences less resistance to deformation than pack ice. Here, we introduce a new coupled framework involving the spectral wave model WAVEWATCH III and the sea ice model neXtSIM, which includes a Maxwell elasto-brittle...
Tipo: Text
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00679/79084/81534.pdf

The North Atlantic Eddy Heat Transport and Its Relation with the Vertical Tilting of the Gulf Stream Axis
Provedor de dados: 5
Autores: 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
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00391/50247/50871.pdf

Satellite-observed drop of Arctic sea ice growth in winter 2015-2016
Provedor de dados: 5
Autores: 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

An assessment of the Arctic Ocean in a suite of interannual CORE-II simulations. Part II: Liquid freshwater
Provedor de dados: 5
Autores: 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

The impact of tides on simulated landfast ice in a pan-Arctic ice-ocean model
Provedor de dados: 5
Autores: 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

Early Eocene vigorous ocean overturning and its contribution to a warm Southern Ocean
Provedor de dados: 5
Autores: 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
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00643/75529/76436.pdf

The Beaufort Gyre extent, shape, and location between 2003 and 2014 from satellite observations
Provedor de dados: 5
Autores: 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

Satellite-derived sea ice export and its impact on Arctic ice mass balance
Provedor de dados: 5
Autores: 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
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00460/57122/59048.pdf

Freshwater and its role in the Arctic Marine System: sources, disposition, storage, export, and physical and biogeochemical consequences in the Arctic and global oceans
Provedor de dados: 5
Autores: 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

On the origins of water masses exported along both sides of Greenland: A Lagrangian model analysis
Provedor de dados: 5
Autores: 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
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00005/11591/8232.pdf

Arctic Ocean response to Greenland Sea wind anomalies in a suite of model simulations
Provedor de dados: 5
Autores: 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

Arctic Ocean freshwater content and its decadal memory of sea-level pressure
Provedor de dados: 5
Autores: Johnson, Helen L.; Cornish, Sam B.; Kostov, Yavor; Beer, Emma; Lique, Camille.
Arctic freshwater content (FWC) has increased significantly over the last two decades, with potential future implications for the Atlantic meridional overturning circulation downstream. We investigate the relationship between Arctic FWC and atmospheric circulation in the control run of a coupled climate model. Multiple linear lagged regression is used to extract the response of total Arctic FWC to a hypothetical step increase in the principal components of sea‐level pressure. The results demonstrate that the FWC adjusts on a decadal timescale, consistent with the idea that wind‐driven ocean dynamics and eddies determine the response of Arctic Ocean circulation and properties to a change in surface forcing, as suggested by idealized models and theory....
Tipo: Text
Palavras-chave: Arctic Ocean; Climate change; Interannual variability; Freshwater; Adjustment timescales; Ocean dynamics.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00440/55117/56571.pdf

Meridional transport of salt in the global ocean from an eddy-resolving model
Provedor de dados: 5
Autores: 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
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00192/30319/28790.pdf

Emergence of deep convection in the Arctic Ocean under a warming climate
Provedor de dados: 5
Autores: 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
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00395/50609/51451.pdf

Water mass properties derived from satellite observations in the Barents Sea
Provedor de dados: 5
Autores: 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