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| Registros recuperados: 86 | |
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| Ahyong, Shane T.; Schnabel, Kareen E.; Baba, Keiji. |
| Macquarie Ridge is one of the southernmost seamount ridges, spanning 1600 kilometres from the southern tip of New Zealand to the Australia-Pacific-Antarctic triple junction halfway to Antarctica. Squat lobsters, superfamilies Chirostyloidea and Galatheoidea, are highly diverse at low and mid-latitudes, declining rapidly towards the poles; only 15 of the more than 1000 species have been recorded south of 50 degrees S. Prior to the present study, one species of squat lobster (Munidopsis pyrochela, Munidopsidae) was known from the Macquarie Ridge, but recent research voyages in 2003 and 2008 collected a further five species from both superfamilies and three families. Uroptychus tracey (Chirostylidae) is new to science. Uroptychus insignis (Henderson, 1885) is... |
| Tipo: Text |
Palavras-chave: Anomura; Galatheoidea; Chirostyloidea; New Zealand; Macquarie Ridge; Southern Ocean; Seamount. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00351/46250/46100.pdf |
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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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| Crosta, X; Shemesh, A; Etourneau, J; Yam, R; Billy, I; Pichon, Jj. |
| Most high-southern latitude records of carbon and nitrogen isotopic ratios and elemental ratios are from the Antarctic and Polar Front zones, thus hindering a comprehensive view of nutrient cycling in the Southern Ocean. We present, for the first time, two records from the Subantarctic Zone and the southern Subtropical Zone of the Indian Ocean. These records provide a latitudinal transect covering the main oceanographic systems of the Southern Ocean. Carbon and nitrogen content of the diatom-bound organic matter increases during the last glacial in the Antarctic and Subantarctic zones but does not show a clear climate-related signal in the Subtropical Zone. Comparison of these records with sea-surface temperatures reconstructed at the core locations and... |
| Tipo: Text |
Palavras-chave: Diatoms; Nutrient cycling; Southern Ocean. |
| Ano: 2005 |
URL: https://archimer.ifremer.fr/doc/00230/34075/32543.pdf |
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| Freeman, Natalie M.; Lovenduski, Nicole S.. |
| Widespread ocean acidification is occurring as the ocean absorbs anthropogenic carbon dioxide from the atmosphere, threatening marine ecosystems, particularly the calcifying plankton that provide the base of the marine food chain and play a key role within the global carbon cycle. We use satellite estimates of particulate inorganic carbon (PIC), surface chlorophyll, and sea surface temperature to provide a first estimate of changing calcification rates throughout the Southern Ocean. From 1998 to 2014 we observe a 4% basin-wide reduction in summer calcification, with approximate to 9% reductions in large regions (approximate to 1 x 10(6) km(2)) of the Pacific and Indian sectors. Southern Ocean trends are spatially heterogeneous and primarily driven by... |
| Tipo: Text |
Palavras-chave: Southern Ocean; Calcification; Particulate inorganic carbon; Carbonate ion; Antarctic polar front. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00292/40371/38941.pdf |
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| Convey, P.; Bindschadler, R.; Di Prisco, G.; Fahrbach, E.; Gutt, J.; Hodgson, D. A.; Mayewski, P. A.; Summerhayes, C. P.; Turner, J.; ACCE CONSORTIUM. |
| The Antarctic climate system varies on timescales from orbital, through millennial to sub-annual, and is closely coupled to other parts of the global climate system. We review these variations from the perspective of the geological and glaciological records and the recent historical period from which we have instrumental data (similar to the last 50 years). We consider their consequences for the biosphere, and show how the latest numerical models project changes into the future, taking into account human actions in the form of the release of greenhouse gases and chlorofluorocarbons into the atmosphere. In doing so, we provide an essential Southern Hemisphere companion to the Arctic Climate Impact Assessment. |
| Tipo: Text |
Palavras-chave: Antarctica; Biology; Environmental change; Geology; Glaciology; Southern Ocean. |
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00292/40357/82998.pdf |
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| Godet, Claire; Robuchon, Marine; Leroy, Boris; Cotté, Cedric; Baudena, Alberto; Da Silva, Ophélie; Fabri-ruiz, Salomé; Lo Monaco, Claire; Sergi, Sara; Koubbi, Philippe. |
| Distinguishing regions based on the geographic distribution of both abiotic factors and living organisms is an old but still actual central issue for biogeographers. In the Southern Ocean, the few existing regionalization studies have been carried out either at very large scales or on the relatively small region around the Sub-Antarctic islands of Kerguelen and the Crozet archipelagos. However, regionalization studies at meso-scales (100–300 km) covering the Indian part of the Southern Ocean and adjacent South Indian Ocean are scarce. These waters, ranging from the Subtropical to the polar region, are home to large populations of well-studied top predators that depend on the biomass of less known mid-trophic level species such as zooplankton. To fill those... |
| Tipo: Text |
Palavras-chave: Bioregionalization; Southern Ocean; Indian Ocean; Pelagic ecosystem; Zooplankton; Continuous plankton recorder. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75474/76309.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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| Ingels, Jeroen; Vanreusel, Ann; Brandt, Angelika; Catarino, Ana I.; David, Bruno; De Ridder, Chantal; Dubois, Philippe; Gooday, Andrew J.; Martin, Patrick; Pasotti, Francesca; Robert, Henri. |
| Because of the unique conditions that exist around the Antarctic continent, Southern Ocean (SO) ecosystems are very susceptible to the growing impact of global climate change and other anthropogenic influences. Consequently, there is an urgent need to understand how SO marine life will cope with expected future changes in the environment. Studies of Antarctic organisms have shown that individual species and higher taxa display different degrees of sensitivity to environmental shifts, making it difficult to predict overall community or ecosystem responses. This emphasizes the need for an improved understanding of the Antarctic benthic ecosystem response to global climate change using a multitaxon approach with consideration of different levels of biological... |
| Tipo: Text |
Palavras-chave: Amphipoda; Echinoidea; Foraminifera; Global climate change; Isopoda; Nematoda; Southern Ocean; Zoobenthos. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00296/40762/39758.pdf |
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| Panizzo, Virginia; Crespin, Julien; Crosta, Xavier; Shemesh, Aldo; Masse, Guillaume; Yam, Ruth; Mattielli, Nadine; Cardinal, Damien. |
| Combined high-resolution Holocene δ30Sidiat and δ13Cdiat paleorecords are presented from the Seasonal Ice Zone, East Antarctica. Both data sets reflect periods of increased nutrient utilization by diatoms during the Hypsithermal period (circa 7800 to 3500 calendar years (cal years) B.P.), coincident with a higher abundance of open water diatom species (Fragilariopsis kerguelensis), increased biogenic silica productivity (%BSi), and higher regional summer temperatures. The Neoglacial period (after circa 3500 cal years B.P.) is reflected by an increase in sea ice indicative species (Fragilariopsis curta and Fragilariopsis cylindrus, up to 50%) along with a decrease in %BSi and δ13Cdiat (< −18‰ to −23‰). However, over this period, δ30Sidiat data show an... |
| Tipo: Text |
Palavras-chave: Diatoms; Silicon isotopes; Diatom bound carbon isotopes; Seasonal ice zone; Holocene; Southern Ocean. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00290/40157/39098.pdf |
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| Assmy, Philipp; Cisewski, Boris; Henjes, Joachim; Klaas, Christine; Montresor, Marina; Smetacek, Victor. |
| Ocean iron fertilization experiments enable the quantitative study of processes shaping the structure and functioning of pelagic ecosystems following perturbation under in situ conditions. EIFEX was conducted within a stationary eddy adjacent to the Antarctic Polar Front over 38 days in February/March 2004 and induced a massive diatom bloom. Here, we present the responses in abundance and biomass of all identifiable protozooplankton taxa (heterotrophic protists ranging from 2 to 500 mm) during the bloom. Acantharia, dinoflagellates and ciliates together contributed >90% of protozooplankton biomass in the upper 100 m throughout the experiment with heterotrophic nanoflagellates, nassellaria, spumellaria, phaeodaria, foraminifera and the taxopodidean... |
| Tipo: Text |
Palavras-chave: Protozoa; Rhizaria; Sarcodines; Southern Ocean; Top-down control. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00290/40091/39174.pdf |
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| Le Paih, Nicolas; Hattermann, Tore; Boebel, Olaf; Kanzow, Torsten; Lüpkes, Christof; Rohardt, Gerd; Strass, Volker; Herbette, Steven. |
| The Weddell Sea is of global importance in the formation of dense bottom waters associated with sea‐ice formation and ocean‐ice sheet interaction occurring on the shelf areas. In this context, the Weddell Sea boundary current system (BCS) presents a major conduit for transporting relatively warm water to the Weddell Sea ice shelves and for exporting {some modified form of Wedell Sea deep and bottom waters into the open ocean. This study investigates the downstream evolution of the structure and the seasonality of the BCS along the Weddell Sea continental slope, combining ocean data collected for the past two decades at three study locations. The interannual‐mean geostrophic flow, which follows planetary potential vorticity contours, shifts from being... |
| Tipo: Text |
Palavras-chave: Southern Ocean; Weddell Sea; Antarctic slope current; Surface stress; Flow strength; Teleconnection. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00652/76398/77436.pdf |
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| Moiroud, Mathieu; Puceat, Emmanuelle; Donnadieu, Yannick; Bayon, Germain; Guiraud, Michel; Voigt, Silke; Deconinck, Jean-francois; Monna, Fabrice. |
| Neodymium isotopic compositions (εNd) have been largely used for the last fifty years as a tracer of past ocean circulation, and more intensively during the last decade to investigate ocean circulation during the Cretaceous period. Despite a growing set of data, circulation patterns still remain unclear during this period. In particular, the identification of the deep-water masses and their spatial extension within the different oceanic basins are poorly constrained. In this study we present new deep-water εNd data inferred from the Nd isotope composition of fish remains and Fe-Mn oxyhydroxide coatings on foraminifera tests, along with new εNd data of residual (partly detrital) fraction recovered from DSDP sites 152 (Nicaraguan Rise), 258 (Naturaliste... |
| Tipo: Text |
Palavras-chave: Cretaceous; Neodymium isotopes; Ocean circulation; Southern Ocean. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00278/38962/37502.pdf |
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| Guillermic, Maxence; Lalonde, Stefan; Hendry, Katharine R.; Rouxel, Olivier. |
| Although dissolved concentrations of germanium (Ge) and silicon (Si) in modern seawater are tightly correlated, uncertainties still exist in the modern marine Ge cycle. Germanium stable isotope systematics in marine systems should provide additional constraints on marine Ge sources and sinks, however the low concentration of Ge in seawater presents an analytical challenge for isotopic measurement. Here, we present a new method of pre-concentration of inorganic Ge from seawater which was applied to measure three Ge isotope profiles in the Southern Ocean and deep seawater from the Atlantic and Pacific Oceans. Germanium isotopic measurements were performed on Ge amounts as low as 2.6 ng using a double-spike approach and a hydride generation system coupled to... |
| Tipo: Text |
Palavras-chave: Stable isotopes; Germanium; Silicon; Sponges; Southern Ocean; Chemical oceanography. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00388/49956/50529.pdf |
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| Pena, L. D.; Goldstein, S. L.; Hemming, S. R.; Jones, K. M.; Calvo, E.; Pelejero, C.; Cacho, I.. |
| The Southern Ocean is increasingly recognized as a key player in the general ocean thermohaline circulation and the global climate system during glacial interglacial transitions. In particular, the advection of Southern Ocean intermediate waters (SOIW), like Antarctic Intermediate Water and Sub-Antarctic Mode Water, to the Eastern Equatorial Pacific (EEP), through a so-called "oceanic tunnelling" mechanism, is an important means for rapid transfer of climatic signals (such as heat, fresh water, salt, and chemical species) from high-to-low latitudes. However, information on how intermediate water advection rates changed in the past, and particularly during deglaciations, is fragmentary. We present new results for Nd isotopes (epsilon(Nd)) in cleaned... |
| Tipo: Text |
Palavras-chave: Neodymium isotopes; Planktonic foraminifera; Intermediate water masses; Eastern Equatorial Pacific; Equatorial Undercurrent; Southern Ocean. |
| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00264/37543/36928.pdf |
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| Verdy, A.; Mazloff, M. R.. |
| A Biogeochemical Southern Ocean State Estimate (B-SOSE) is introduced that includes carbon and oxygen fields as well as nutrient cycles. The state estimate is constrained with observations while maintaining closed budgets and obeying dynamical and thermodynamic balances. Observations from profiling floats, shipboard data, underway measurements, and satellites are used for assimilation. The years 2008-2012 are chosen due to the relative abundance of oxygen observations from Argo floats during this time. The skill of the state estimate at fitting the data is assessed. The agreement is best for fields that are constrained with the most observations, such as surface pCO(2) in Drake Passage (44% of the variance captured) and oxygen profiles (over 60% of the... |
| Tipo: Text |
Palavras-chave: Southern Ocean; State estimation; Biogeochemistry. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00662/77394/78995.pdf |
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| Roquet, Fabien; Wunsch, Carl; Forget, Gael; Heimbach, Patrick; Guinet, Christophe; Reverdin, Gilles; Charrassin, Jean-benoit; Bailleul, Frederic; Costa, Daniel P.; Huckstadt, Luis A.; Goetz, Kimberly T.; Kovacs, Kit M.; Lydersen, Christian; Biuw, Martin; Nost, Ole A.; Bornemann, Horst; Ploetz, Joachim; Bester, Marthan N.; Mcintyre, Trevor; Muelbert, Monica C.; Hindell, Mark A.; Mcmahon, Clive R.; Williams, Guy; Harcourt, Robert; Field, Iain C.; Chafik, Leon; Nicholls, Keith W.; Boehme, Lars; Fedak, Mike A.. |
| Over the last decade, several hundred seals have been equipped with conductivity-temperature-depth sensors in the Southern Ocean for both biological and physical oceanographic studies. A calibrated collection of seal-derived hydrographic data is now available, consisting of more than 165,000 profiles. The value of these hydrographic data within the existing Southern Ocean observing system is demonstrated herein by conducting two state estimation experiments, differing only in the use or not of seal data to constrain the system. Including seal-derived data substantially modifies the estimated surface mixed-layer properties and circulation patterns within and south of the Antarctic Circumpolar Current. Agreement with independent satellite observations of sea... |
| Tipo: Text |
Palavras-chave: Animal-borne sampling; Southern Ocean; State estimation; Hydrography. |
| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00241/35252/33765.pdf |
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| Faure, Vincent; Arhan, Michel; Speich, Sabrina; Gladyshev, Sergey. |
| ARGO hydrographic profiles, two hydrographic transects and satellite measurements of air-sea exchange parameters were used to characterize the properties and seasonal heat budget variations of the Surface Mixed Layer (SML) south of Africa. The analysis distinguishes the Subtropical domain (STZ) and the Subantarctic Zone (SAZ), Polar Frontal Zone (PFZ) and Antarctic Zone (AZ) of the Antarctic Circumpolar Current. While no Subantarctic Mode Water forms in that region, occurrences of deep SML (up to similar to 450 m) are observed in the SAZ in anticyclones detached from the Agulhas Current retroflection or Agulhas Return Current. These are present latitudinally throughout the SAZ, but preferentially at longitudes 10-20A degrees E where, according to previous... |
| Tipo: Text |
Palavras-chave: Ocean surface mixed layer; Heat budget; Southern Ocean; Agulhas Current retroflection. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00048/15953/15833.pdf |
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| Registros recuperados: 86 | |
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