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| Registros recuperados: 86 | |
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| Cheize, Marie; Planquette, H.f.; Fitzsimmons, J.n.; Pelleter, Ewan; Sherrell, R.m.; Lambert, Christophe; Bucciarelli, E.; Sarthou, G.; Le Goff, Marion; Liorzou, Celine; Chéron, Sandrine; Viollier, E.; Gayet, Nicolas. |
| A number of trace metals play essential roles in marine ecosystem structure and biological productivity. Until recently, it has been argued that phytoplankton access primarily dissolved iron, while particulate iron was considered a refractory material with little use biologically and limited interaction with the dissolved pool. In order to assess the transfer mechanisms between sediment-sourced particulate trace metals and the dissolved pool, we conducted a 14-month incubation that reacted resuspended sediments with natural seawater, both originating from the Kerguelen area (KEOPS cruises; Southern Ocean), in the dark, and at concentrations replicating natural conditions. Three types of sediments were investigated (named BioSi, BioSi + Ca, and Basalt),... |
| Tipo: Text |
Palavras-chave: Suspended particle dissolution; Sediment; Iron; Manganese; Biogenic silica; Southern Ocean; Kerguelen. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00460/57197/59166.pdf |
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| Jansen, Jan; Dunstan, Piers K.; Hill, Nicole A.; Koubbi, Philippe; Melbourne‐thomas, Jessica; Causse, Romain; Johnson, Craig R.. |
| Characterising the spatial distribution and variation of species communities and validating these characteristics with data from the field are key elements for an ecosystem‐based approach to management. However, models of species distributions that yield community structure are usually not linked to models of community dynamics, constraining understanding and management of the ecosystem, particularly in data‐poor regions. Here we use a qualitative network model to predict changes in Antarctic benthic community structure between major marine habitats characterised largely by seafloor depth and slope, and use multivariate mixture models of species distributions to validate the community dynamics. Further, we then assess how future increases in primary... |
| Tipo: Text |
Palavras-chave: Deep‐sea; Ecosystem structure; Ecosystem dynamic; Southern Ocean; Antarctica; Continental shelf; Upper slope; Species archetype model; Qualitative network model; Spatial model. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00599/71143/69460.pdf |
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| Jabaud-jan, A; Metzl, N; Brunet, C; Poisson, A; Schauer, B. |
| The interannual variations of the carbon dioxide system and air-sea CO(2) fluxes are analyzed in the southwestern Indian Ocean from both in situ (Ocean Indien Service d'Observations cruises in 1998 and 2000) and simulated oceanic CO(2) fugacity f(CO2) dissolved inorganic carbon, total alkalinity, and nutrients. During austral summer of 1998, the ocean was warmer from 20degreesS to 60degreesS. In the Subtropical Zone (20degreesS-37degreesS), the warming, associated with the subtropical dipole pattern, creates an oceanic CO(2) source around 2 mmol m(-2) d(-1) in January 1998 where all previous observations, included in 2000, indicated that this region was a small sink in summer. In the Sub-Antarctic and Polar Front Zones (37degreesS-50degreesS), the f(CO2)... |
| Tipo: Text |
Palavras-chave: Air-sea CO(2) fluxes; Southern Ocean; Seasonal and interannual variabilities; Warm anomaly. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00228/33919/32208.pdf |
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| Le Bourg, Baptiste. |
| Like in the rest of the world, climate change impacts the Southern Ocean, but not in the same way in all regions of this ocean. Changes in sea ice cover around the Antarctic continent are one of the most visible manifestations. For example, sea ice cover has decreased significantly in the Western Antarctic Peninsula while it tends to increase slightly on the rest of the coastline of the continent. These changes in environmental conditions influence the functioning of the ecosystems of this ocean. In particular, the disappearance or persistence of sea ice in a region where it was seasonally present may prevent the appearance of summer phytoplankton blooms, thus impacting the dynamics of krill populations and their predators in the pelagic environment. The... |
| Tipo: Text |
Palavras-chave: Sea stars; Southern Ocean; Trophic ecology; Stable isotopes. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00633/74468/74296.pdf |
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| Berthier, Etienne; Le Bris, Raymond; Mabileau, Laure; Testut, Laurent; Remy, Frederique. |
| We observed the wastage of ice masses on the Kerguelen Islands ( Indian Ocean, 49 degrees S, 69 degrees E) using historical information and recent satellite data. Overall, the total ice-covered area on the islands declined from 703 to 552 km(2) between 1963 and 2001, a reduction of 21%. The area of Cook ice cap ( the main ice body) decreased asymmetrically from 501 to 403 km(2). West flowing glaciers lost 11% of their area, while east flowing glaciers lost 28%. After 1991, the retreat rate accelerated from 1.9 km(2)/a ( 1963-1991) to 3.8 km(2)/a ( 1991-2003). Between 1963 and 2000, the ice volume loss was 25-30 km(3), equivalent to an area-average ice-thinning rate of 1.4-1.7 m/a. The glacial retreat took place in the climatic context of a relatively low... |
| Tipo: Text |
Palavras-chave: Ice caps; Climate change; Remote sensing; Kerguelen Islands; Southern Ocean; Mass balance. |
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00219/33069/31557.pdf |
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| Prego, R; Park, Yh; Barciela, Mc; Morvan, J; Poncin, J; Treguer, P. |
| The subantarctic frontal zone surveyed during the April-May 1991 SUZIL cruise in the Crozet-Kerguelen Amsterdam area shows a strong horizontal (north to south) gradient of dissolved silicate, increasing with depth, from 5 to 10 mu molSi kg(-1) at 100 m, and 10 to 70 mu molSi kg(-1) at 600 m. The northern limit of this frontal zone, which is formed by the confluence of the Subtropical and Subantarctic Fronts, is delimited at the surface by the 2 mu molSi kg(-1) silicate isoline. Silicate-salinity diagrams also allow different water regimes to be positioned relative to the frontal zone. This sloping interface is between two water bodies, one to the north with more saline subtropical waters of less concentrated silicate than the southern one, corresponding to... |
| Tipo: Text |
Palavras-chave: Silicate; Tracer; Frontal zone; Silicate-salinity diagram; Crozet Basin; Southern Ocean. |
| Ano: 1999 |
URL: https://archimer.ifremer.fr/doc/00239/35063/34593.pdf |
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| Hauck, J.; Voelker, C.; Wang, T.; Hoppema, M.; Losch, M.; Wolf-gladrow, D. A.. |
| Stratospheric ozone depletion and emission of greenhouse gases lead to a trend of the southern annular mode (SAM) toward its high-index polarity. The positive phase of the SAM is characterized by stronger than usual westerly winds that induce changes in the physical carbon transport. Changes in the natural carbon budget of the upper 100 m of the Southern Ocean in response to a positive SAM phase are explored with a coupled ecosystem-general circulation model and regression analysis. Previously overlooked processes that are important for the upper ocean carbon budget during a positive SAM period are identified, namely, export production and downward transport of carbon north of the polar front (PF) as large as the upwelling in the south. The limiting... |
| Tipo: Text |
Palavras-chave: Southern Ocean; Southern annular mode; Carbon cycle; Carbon sink. |
| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00292/40352/38988.pdf |
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| Xue, Liang; Gao, Libao; Cai, Wei-jun; Yu, Weidong; Wei, Meng. |
| Using observational data collected south of Tasmania during 14 austral summer cruises during 1993-2011, we examined the response of sea surface fugacity of carbon dioxide (fCO(2)) to the Southern Annular Mode (SAM) shift, which occurred around 2000. In the southern part of the Southern Ocean (SO) or the Polar Zone (PZ) and the Polar Frontal Zone (PFZ), fCO(2) increased faster at the sea surface than in the atmosphere before the SAM shift, but not after the shift. In the northern part of the SO or the Subantarctic Zone (SAZ), however, surface fCO(2) increased faster than atmospheric fCO(2) both before and after the shift. The SAM shift had an important influence on the surface fCO(2) trend in the PZ and PFZ but not in the SAZ, which we attribute to... |
| Tipo: Text |
Palavras-chave: Southern Ocean; Southern Annular Mode shift; Carbon cycling; Upwelling; South of Tasmania. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00292/40369/38947.pdf |
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| Ebersbach, Friederike; Assmy, Philipp; Martin, Patrick; Schulz, Isabelle; Wolzenburg, Sina; Noethig, Eva-maria. |
| The taxonomic composition and types of particles comprising the downward particle flux were examined during the mesoscale artificial iron fertilisation experiment LOHAFEX. The experiment was conducted in low-silicate waters of the Atlantic Sector of the Southern Ocean during austral summer (January-March 2009), and induced a bloom dominated by small flagellates. Downward particle flux was low throughout the experiment, and not enhanced by addition of iron; neutrally buoyant sediment traps contained mostly faecal pellets and faecal material apparently reprocessed by mesozooplankton. TEP fluxes were low, <= 5 mg GX eq. m(-2) d(-1), and a few phytodetrital aggregates were found in the sediment traps. Only a few per cent of the POC flux was found in the... |
| Tipo: Text |
Palavras-chave: Nano- and picoplankton; Export flux; Iron fertilisation; Protists; Sediment trap; Southern Ocean. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00290/40121/39348.pdf |
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| Cherel, Y; Ducatez, S; Fontaine, C; Richard, Patrice; Guinet, C. |
| Trophic interactions between organisms are the main drivers of ecosystem dynamics, but scant dietary information is available for wide-ranging predators during migration. We investigated feeding habits of a key consumer of the Southern Ocean, the southern elephant seal Miroungia leonina, by comparing its blood delta(13) C and delta N-15 values with those of various marine organisms, including crustaceans, squid, fishes, seabirds and fur seals. At the end of winter, delta C-13 values (-23.1 to -20.1 parts per thousand)indicate that female elephant seals forage mainly in the vicinity of the Polar Front and in the Polar Frontal Zone. Trophic levels derived from delta N-15 values (trophic level = 4.6) show that the southern elephant seal is a top consumer in... |
| Tipo: Text |
Palavras-chave: Squid; Southern Ocean; Pelagic ecosystem; Myctophid; Mesopelagic fish; Cephalopod. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-5021.pdf |
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| Firing, Yvonne L.; Mcdonagh, Elaine L.; King, Brian A.; Desbruyeres, Damien. |
| Observations made on 21 occupations between 1993 and 2016 of GO-SHIP line SR1b in eastern Drake Passage show an average temperature of 0.53 degrees C deeper than 2000 dbar, with no significant trend, but substantial year-to-year variability (standard deviation 0.08 degrees C). Using a neutral density framework to decompose the temperature variability into isopycnal displacement (heave) and isopycnal property change components shows that approximately 95% of the year-to-year variance in deep temperature is due to heave. Changes on isopycnals make a small contribution to year-to-year variability but contribute a significant trend of -1.40.6 m degrees C per year, largest for density ((n))>28.1, south of the Polar Front (PF). The heave component is... |
| Tipo: Text |
Palavras-chave: Temperature; Trends; Southern Ocean. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00387/49812/50390.pdf |
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| Hemery, Lenaig G.; Ameziane, Nadia; Eleaume, Marc. |
| This circumpolar dataset of the comatulid (Echinodermata: Crinoidea) Promachocrinus kerguelensis (Carpenter, 1888) from the Southern Ocean, documents biodiversity associated with the specimens sequenced in Hemery et al. (2012). The aim of Hemery et al. (2012) paper was to use phylogeographic and phylogenetic tools to assess the genetic diversity, demographic history and evolutionary relationships of this very common and abundant comatulid, in the context of the glacial history of the Antarctic and Sub-Antarctic shelves (Thatje et al. 2005, 2008). Over one thousand three hundred specimens (1307) used in this study were collected during seventeen cruises from 1996 to 2010, in eight regions of the Southern Ocean: Kerguelen Plateau, Davis Sea, Dumont d'Urville... |
| Tipo: Text |
Palavras-chave: Antarctica; Crinoidea; Cytochrome Oxydase subunit I; Echinodermata; Phylogeography; Promachocrinus; Southern Ocean; Sub-Antarctic. |
| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00296/40758/39749.pdf |
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| Song, Hajoon; Marshall, John; Munro, David R.; Dutkiewicz, Stephanie; Sweeney, Colm; Mcgillicuddy, D. J., Jr.; Hausmann, Ute. |
| We investigate the role of mesoscale eddies in modulating air-sea CO2 flux and associated biogeochemical fields in Drake Passage using in situ observations and an eddy-resolving numerical model. Both observations and model show a negative correlation between temperature and partial pressure of CO2 (pCO(2)) anomalies at the sea surface in austral summer, indicating that warm/cold anticyclonic/cyclonic eddies take up more/less CO2. In austral winter, in contrast, relationships are reversed: warm/cold anticyclonic/cyclonic eddies are characterized by a positive/negative pCO(2) anomaly and more/less CO2 outgassing. It is argued that DIC-driven effects on pCO(2) are greater than temperature effects in austral summer, leading to a negative correlation. In... |
| Tipo: Text |
Palavras-chave: CO2 flux; Mesoscale eddy; Southern Ocean; Vertical mixing; Nutrient fluxes. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00383/49407/49894.pdf |
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| Cortese, G.; Abelmann, A.; Gersonde, R.. |
| A submillennial resolution, radiolarian-based record of summer sea surface temperature (SST) documents the last five glacial to interglacial transitions at the subtropical front, southern Atlantic Ocean. Rapid fluctuations occur both during glacial and interglacial intervals, and sudden cooling episodes at glacial terminations are recurrent. Surface hydrography and global ice volume proxies from the same core suggest that summer SST increases prior to terminations lead global ice- volume decreases by 4.7 +/- 3.7 ka (in the eccentricity band), 6.9 +/- 2.5 ka (obliquity), and 2.7 +/- 0.9 ka (precession). A comparison between SST and benthic delta C-13 suggests a decoupling in the response of northern subantarctic surface, intermediate, and deep water masses... |
| Tipo: Text |
Palavras-chave: Paleotemperature; Radiolaria; Southern Ocean. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00236/34725/33297.pdf |
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| Brandt, Angelina. |
| During an expedition with RV Victor Hensen (1994) and the RV Polarstern (1996) Isopoda Sphaeromatidae were collected in and off the eastern entrance of the Beagle Channel. The species found, Caecocassidias patagonica Kussakin, 1967, Cassidinopsis emarginata (Guérin-Méneville, 1843) and Moruloidea darwinii (Cunningham, 1871), were previously all poorly or insufficiently described; therefore a redescription is presented herein. Exosphaeroma gigas (Leach, 1818) was also collected frequently, but it was already redescribed earlier and thus only the localities are presented. Moreover, a new species, Cymodopsis beageli, n.sp., which is most closely allied to Cymodopsis sphyracephalata Hurley & Janssen, 1977, is described from the Beagle Channel. |
| Tipo: Article / Letter to the editor |
Palavras-chave: Crustacea; Isopoda; Taxonomy; Beagle Channel; South America; Southern Ocean; Subantarctic. |
| Ano: 1998 |
URL: http://www.repository.naturalis.nl/record/504937 |
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| Registros recuperados: 86 | |
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