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| Charrassin, J. -b.; Hindell, M.; Rintoul, S. R.; Roquet, Fabien; Sokolov, S.; Biuw, M.; Costa, D.; Boehme, L.; Lovell, P.; Coleman, R.; Timmermann, R.; Meijers, A.; Meredith, M.; Park, Y. -h.; Bailleul, F.; Goebel, M.; Tremblay, Y; Bost, C. -a.; Mcmahon, C. R.; Field, I. C.; Fedak, M. A.; Guinet, C. |
| Polar regions are particularly sensitive to climate change, with the potential for significant feedbacks between ocean circulation, sea ice, and the ocean carbon cycle. However, the difficulty in obtaining in situ data means that our ability to detect and interpret change is very limited, especially in the Southern Ocean, where the ocean beneath the sea ice remains almost entirely unobserved and the rate of sea-ice formation is poorly known. Here, we show that southern elephant seals (Mirounga leonina) equipped with oceanographic sensors can measure ocean structure and water mass changes in regions and seasons rarely observed with traditional oceanographic platforms. In particular, seals provided a 30-fold increase in hydrographic profiles from the sea-ice... |
| Tipo: Text |
Palavras-chave: Antarctic circumpolar current; Instrumentation; Marine predators; Ocean observation; Sea-ice modeling. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00241/35239/33750.pdf |
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| Park, Y. -h.; Lee, J. -h.; Durand, I.; Hong, C. -s.. |
| The Thorpe scale is an energy-containing vertical overturning scale of large eddies associated with shear-generated turbulence. This study investigates indirect estimates of vertical diffusivities from the Thorpe scale method in the polar front region east of the Kerguelen Islands based on fine-scale density profiles gathered during the 2011 KEOPS2 (KErguelen Ocean and Plateau compared Study 2) cruise. These diffusivities are validated in comparison with diffusivities estimated from the turbulence dissipation rate directly measured via a TurboMAP (Turbulence ocean Microstructure Acquisition Profiler) microstructure profiler. The results are sensitive to the choice of the diffusivity parameterization and the overturn ratio R-o, and the optimal results have... |
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| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00291/40210/39323.pdf |
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| Bown, J.; Boye, M.; Laan, P.; Bowie, A. R.; Park, Y. -h.; Jeandel, C.; Nelson, D. M.. |
| Processes of cobalt (Co) entrainment from shelf sediments over the Kerguelen Plateau were studied during the KEOPS (Kerguelen Ocean Plateau compared Study) in order to explain the exceptionally high dissolved cobalt concentrations that have been measured in the surface waters above the Kerguelen Plateau, and in intermediate and deep waters above its eastern slope. Lateral advection and dissolution of Co contained in basalt sediments around Heard Island, a main source of lithogenic Co in the study area, were shown to imprint the process of surface enrichment over the plateau. Dissolved Co enrichment was strongest at the intercept of the eastern slope with intermediate and deep waters, probably due to more efficient mobilisation of the sediments in the slope... |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00139/25058/23163.pdf |
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| Sekma, H.; Park, Y. -h.; Vivier, F.. |
| The major mechanisms of the oceanic poleward heat flux in the Southern Ocean are still in debate. The long-standing belief stipulates that the poleward heat flux across the Antarctic Circumpolar Current (ACC) is mainly due to mesoscale transient eddies and the cross-stream heat flux by time-mean flow is insignificant. This belief has recently been challenged by several numerical modeling studies, which stress the importance of mean flow for the meridional heat flux in the Southern Ocean. Here, this study analyzes moored current meter data obtained recently in the Fawn Trough, Kerguelen Plateau, to estimate the cross-stream heat flux caused by the time-mean flow and transient eddies. It is shown that the poleward eddy heat flux in this southern part of the... |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00181/29196/27591.pdf |
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| Favier, V.; Verfaillie, D.; Berthier, E.; Menegoz, M.; Jomelli, V.; Kay, J. E.; Ducret, L.; Malbeteau, Y.; Brunstein, D.; Gallee, H.; Park, Y. -h.; Rinterknecht, V.. |
| The ongoing retreat of glaciers at southern sub-polar latitudes is particularly rapid and widespread. Akin to northern sub-polar latitudes, this retreat is generally assumed to be linked to warming. However, no long-term and well-constrained glacier modeling has ever been performed to confirm this hypothesis. Here, we model the Cook Ice Cap mass balance on the Kerguelen Islands (Southern Indian Ocean, 49 degrees S) since the 1850s. We show that glacier wastage during the 2000s in the Kerguelen was among the most dramatic on Earth. We attribute 77% of the increasingly negative mass balance since the 1960s to atmospheric drying associated with a poleward shift of the mid-latitude storm track. Because precipitation modeling is very challenging for the current... |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00488/60016/63266.pdf |
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| D'Ovidio, F.; Della Penna, A.; Trull, T. W.; Nencioli, F.; Pujol, M. -i.; Rio, M.-h; Park, Y. -h.; Cotte, C.; Zhou, M.; Blain, S.. |
| Field campaigns are instrumental in providing ground truth for understanding and modeling global ocean biogeochemical budgets. A survey however can only inspect a fraction of the global oceans, typically a region hundreds of kilometers wide for a temporal window of the order of (at most) several weeks. This spatiotemporal domain is also the one in which the mesoscale activity induces through horizontal stirring a strong variability in the biogeochemical tracers, with ephemeral, local contrasts which can easily mask the regional and seasonal gradients. Therefore, whenever local in situ measures are used to infer larger-scale budgets, one faces the challenge of identifying the mesoscale structuring effect, if not simply to filter it out. In the case of the... |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00296/40722/39723.pdf |
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