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| Sokolov, Serguei; Rintoul, Stephen R.. |
| High resolution hydrographic sections and maps of the gradient of sea surface height (SSH) reveal that the Antarctic Circumpolar Current (ACC) consists of multiple jets or frontal filaments. Here we use a 15 year time series of SSH observations to determine the circumpolar structure and distribution of the ACC fronts. The jets are consistently aligned with particular streamlines along the entire circumpolar path, confirming and extending the results of an earlier study restricted to the region south of Australia. The intensity of the fronts (as measured by the cross-front gradient of SSH) varies along the fronts and the individual branches merge and diverge, often in response to interactions with bathymetry. Maps of absolute velocity at 1000 m depth... |
| Tipo: Text |
Palavras-chave: Southern Ocean; Antarctic Circumpolar Current. |
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00253/36387/34931.pdf |
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| Koubbi, Philippe; Ozouf-costaz, Catherine; Goarant, Anne; Moteki, Masato; Hulley, Percy-alexander; Causse, Romain; Dettai, Agnes; Duhamel, Guy; Pruvost, Patrice; Tavernier, Eric; Post, Alexandra L.; Beaman, Robin J.; Rintoul, Stephen R.; Hirawake, Toru; Hirano, Daisuke; Ishimaru, Takashi; Riddle, Martin; Hosie, Graham. |
| Ecoregions are defined in terms of community structure as a function of abiotic or even anthropogenic forcing. They are meso-scale structures defined as the potential habitat of a species or the predicted communities geographic extent. We assume that they can be more easily defined for long-lived species, such as benthos or neritic fish, in the marine environment. Uncertainties exist for the pelagic realm because of its higher variability, plus little is known about the meso- and bathypelagic zones. A changing environment and modification of habitats will probably drive new communities from plankton to fish or top predators. We need baseline studies, such as those of the Census of Antarctic Marine Life, and databases like SCAR-MarBIN as tools for... |
| Tipo: Text |
Palavras-chave: East Antarctic shelf; Ichthyofauna; Ecoregionalisation; Generalized dissimilarity modeling; Dumont d'Urville Sea. |
| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00236/34740/33086.pdf |
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| Brown, Mark V.; Lauro, Federico M.; Demaere, Matthew Z.; Muir, Les; Wilkins, David; Thomas, Torsten; Riddle, Martin J.; Fuhrman, Jed A.; Andrews-pfannkoch, Cynthia; Hoffman, Jeffrey M.; Mcquaid, Jeffrey B.; Allen, Andrew; Rintoul, Stephen R.; Cavicchioli, Ricardo. |
| The ubiquitous SAR11 bacterial clade is the most abundant type of organism in the world’s oceans, but the reasons for its success are not fully elucidated. We analysed 128 surface marine metagenomes, including 37 new Antarctic metagenomes. The large size of the data set enabled internal transcribed spacer (ITS) regions to be obtained from the Southern polar region, enabling the first global characterization of the distribution of SAR11, from waters spanning temperatures −2 to 30°C. Our data show a stable co-occurrence of phylotypes within both ‘tropical’ (>20°C) and ‘polar’ (<10°C) biomes, highlighting ecological niche differentiation between major SAR11 subgroups. All phylotypes display transitions in abundance that are strongly correlated with... |
| Tipo: Text |
Palavras-chave: Adaptive radiation; Antarctica; Metagenome; Pelagibacter; Phylotype distribution. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00140/25132/23242.pdf |
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| Sallee, Jean-baptiste; Matear, Richard J.; Rintoul, Stephen R.; Lenton, Andrew. |
| The oceans slow the rate of climate change by absorbing about 25% of anthropogenic carbon dioxide emissions annually. The Southern Ocean makes a substantial contribution to this oceanic carbon sink: more than 40% of the anthropogenic carbon dioxide in the ocean has entered south of 40° S. The rate-limiting step in the oceanic sequestration of anthropogenic carbon dioxide is the transfer of carbon across the base of the surface mixed layer into the ocean interior, a process known as subduction. However, the physical mechanisms responsible for the subduction of anthropogenic carbon dioxide are poorly understood. Here we use observationally based estimates of subduction and anthropogenic carbon concentrations in the Southern Ocean to determine the mechanisms... |
| Tipo: Text |
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| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00140/25129/82433.pdf |
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| Cossa, Daniel; Heimbuerger, Lars-eric; Lannuzel, Delphine; Rintoul, Stephen R.; Butler, Edward C. V.; Bowie, Andrew R.; Averty, Bernard; Watson, Roslyn J.; Remenyi, Tomas. |
| We present here the first mercury speciation study in the water column of the Southern Ocean, using a high-resolution south-to-north section (27 stations from 65.50 degrees S to 44.00 degrees S) with up to 15 depths (0-4440 m) between Antarctica and Tasmania (Australia) along the 140 degrees E meridian. In addition, in order to explore the role of sea ice in Hg cycling, a study of mercury speciation in the "snow-sea ice-seawater" continuum was conducted at a coastal site, near the Australian Casey station (66.40 degrees S; 101.14 degrees E). In the open ocean waters, total Hg (Hg(T)) concentrations varied from 0.63 to 2.76 pmol L(-1) with "transient-type" vertical profiles and a latitudinal distribution suggesting an atmospheric mercury source south of the... |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00041/15221/12677.pdf |
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| Sokolov, Serguei; Rintoul, Stephen R.. |
| Maps of the gradient of sea surface height (SSH) and sea surface temperature (SST) reveal that the Antarctic Circumpolar Current (ACC) consists of multiple jets or frontal filaments. The braided and patchy nature of the gradient fields seems at odds with the traditional view, derived from hydrographic sections, that the ACC is made up of three continuous circumpolar fronts. By applying a nonlinear fitting procedure to 638 weekly maps of SSH gradient (del SSH), it is shown that the distribution of maxima in del SSH (i.e., fronts) is strongly peaked at particular values of absolute SSH (i.e., streamlines). The association between the jets and particular streamlines persists despite strong topographic and eddy - mean flow interactions, which cause the jets to... |
| Tipo: Text |
Palavras-chave: Jets; Currents; Sea surface temperature; Ocean circulation. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00235/34616/32952.pdf |
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| Rintoul, Stephen R.; Sokolov, Serguei; Massom, Robert A.. |
| An extraordinary sea ice tongue developed near 85 degrees E over a period of 30 days in April-May 2002. The ice tongue extended to the north more than 800 km from the surrounding ice edge and covered an area greater than 200,000 km 2. Satellite measurements of ice extent and roughness characteristics demonstrate that the tongue persisted as a distinct feature throughout the winter. Remote sensing observations between 1978 and 2004 confirm that ice tongues occur frequently at this location, although the 2002 tongue was particularly pronounced. We show that ocean currents and winds conspire to favor the development of ice tongues at this location. Mean streamlines of the southern part of the Antarctic Circumpolar Current turn sharply to the north near 85... |
| Tipo: Text |
Palavras-chave: Antarctic sea ice; Ice tongue; Ice advection. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00253/36388/34930.pdf |
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| Herraiz-borreguero, Laura; Rintoul, Stephen R.. |
| Subantarctic Mode Water (SAMW) is formed by deep mixing on the equatorward side of the Antarctic Circumpolar Current. The subduction and export of SAMW from the Southern Ocean play an important role in global heat, freshwater, carbon, and nutrient budgets. However, the formation process and variability of SAMW remain poorly understood, largely because of a lack of observations. To determine the temporal variability of SAMW in the Australian sector of the Southern Ocean, we used a 15 year time series of repeat expendable bathythermograph sections from 1993 to 2007, seven repeat conductivity-temperature-depth sections from 1991 to 2001, and sea surface height maps. The mean temperature of the SAMW lies between 8.5 degrees C and 9.5 degrees C (mean of 8.8... |
| Tipo: Text |
Palavras-chave: Subantarctic Mode Water; Subantarctic Front; Mesoscale features; Water mass variability; Southern Ocean. |
| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00253/36385/34926.pdf |
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