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| Registros recuperados: 38 | |
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| Cortese, G; Abelmann, A; Gersonde, R. |
| ODP Site 1089 is optimally located in order to monitor the occurrence of maxima in Agulhas heat and salt spillage from the Indian to the Atlantic Ocean. Radiolarian-based paleotemperature transfer functions allowed to reconstruct the climatic history for the last 450 kyr at this location. A warm sea surface temperature anomaly during Marine Isotope Stage (MIS) 10 was recognized and traced to other oceanic records along the surface branch of the global thermolialine (THC) circulation system, and is particularly marked at locations where a strong interaction between oceanic and atmospheric overturning cells and fronts occurs. This anomaly is absent in the Vostok ice core deuterium, and in oceanic records from the Antarctic Zone. However, it is present in the... |
| Tipo: Text |
Palavras-chave: Agulhas; Paleotemperature; Radiolarians; South Atlantic. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00229/34028/32422.pdf |
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| Fukuda,Marcelo Veronesi; Menezes-Moura,Andrezza Ribeiro; Guimarães,Carmen Regina Parisotto; Ruta,Christine. |
| Abstract We describe herein a new species of the abundant polychaete family Syllidae, Exogone brasiliensis sp. nov. The new species is characterized by a peculiar morphology of anterior body falcigers, with shafts and blades modified specially in chaetigers 1 and 2; falcigers until chaetiger 5 different from those of the rest of the body; and dorsal simple chaetae from midbody onwards unique in the genus, nearly straight, subdistally swollen in one side only, distally rounded. Exogone brasiliensis sp. nov. is described based on detailed morphological analyses under optical and scanning electron microscopes, and compared to its most similar congeners. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: “Polychaeta”; South Atlantic; New species; Brazil. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0031-10492019000100247 |
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| Ansorge, Isabelle J.; Baringer, Molly; Campos, Edmo J.d.; Dong, S.; Fine, R.a.; Garzoli, Silvia L.; Goni, Gustavo; Meinen, Christopher S.; Perez, R.c.; Piola, Alberto R.; Roberts, M.j.; Speich, Sabrina; Sprintall, J.; Terre Terrillon, Thierry; Van Den Berg, M.a.. |
| The meridional overturning circulation (MOC) is a global system of surface, intermediate, and deep ocean currents. The MOC connects the surface layer of the ocean and the atmosphere with the huge reservoir of the deep sea and is the primary mechanism for transporting heat, freshwater, and carbon between ocean basins. Climate models show that past changes in the strength of the MOC were linked to historical climate variations. Further research suggests that the MOC will continue to modulate climate change scenarios on time scales ranging from decades to centuries [Latif et al., 2006]. |
| Tipo: Text |
Palavras-chave: South Atlantic; Meridional Overturning Circulation; CPIES. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00175/28609/27109.pdf |
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| Thatcher,Vernon E.; Pereira Júnior,Joaber. |
| Brasilochondria riograndensis gen. nov., sp. nov. (Copepoda, Chondracanthidae) a parasite of the flounder, Paralichthys orbignyanus (Valenciennes, 1839), is described. The new genus has a spherical head a post-mandibular "neck" and two pairs of modified biramous legs. In these respects, it resembles Argentinochondria patagonensis Etchegoin, Timi & Sardella, 2003. In the Argentine genus, however, the bulbous head has a medial constriction and the posterior of the female lacks the lateral extensions that are present in the new genus. Pseudolernentoma brasiliensis Luque & Alves, 2003, also resembles the new genus but it lacks the lateral extensions of the trunk and the latter is cylindrical rather than flat. The second leg of the new genus is... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Copepod parasite; Chondracanthid; Southern Brasil; South Atlantic. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752004000300014 |
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| Rabouille, C.; Dennielou, Bernard; Baudin, F.; Raimonet, M.; Droz, Laurence; Khripounoff, Alexis; Martinez, P.; Mejanelle, L.; Michalopoulos, P.; Pastor, Lucie; Pruski, A.; Ragueneau, Olivier; Reyss, J.-l.; Ruffine, Livio; Schnyder, J.; Stetten, E.; Taillefert, M.; Tourolle, Julie; Olu, Karine. |
| Carbon and silicon cycles at the Earth surface are linked to long-term variations of atmospheric CO2 and oceanic primary production. In these cycles, the river-sea interface is considered a biogeochemical hotspot, and deltas presently receive and preserve a major fraction of riverine particles in shallow water sediments. In contrast, periods of glacial maximum lowstand were characterized by massive exports of sediments to the deep-sea via submarine canyons and accumulation in deep-sea fans. Here, we calculate present-day mass balances for organic carbon (OC) and amorphous silica (aSi) in the terminal lobe complex of the Congo River deep-sea fan as an analogue for glacial periods. We show that this lobe complex constitutes a megasink with the current... |
| Tipo: Text |
Palavras-chave: Present; Paleoceanography; South Atlantic; Inorganic geochemistry; Organic geochemistry; Sedimentology-marine cores. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00511/62289/66720.pdf |
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| Andriolo,Artur; Rocha,Jesuina M. da; Zerbini,Alexandre N.; Simões-Lopes,Paulo C.; Moreno,Ignacio B.; Lucena,Alineide; Danilewicz,Daniel; Bassoi,Manuela. |
| Ship-based sighting surveys for cetaceans were conducted in the former whaling ground off the northeastern coast of Brazil. The cruises took place in winter and spring of 1998-2001 with the objectives of investigating current distribution and abundance of cetaceans, particularly large whale species taken during whaling. In 1998 the survey were conducted between the parallels 5°30'W and 9°S and the 200 m isobath and the meridian 033°W. A total of about 3,100 nm were surveyed between 1998 and 2001 Surveys were conducted using line transect methods from about 5-10°S, and from the coast to 33°W. A total of 151 sightings (203 individuals) of large whales were recorded on effort. The Antarctic minke whale - Balaenoptera bonaerensis (Burmeister, 1867) was the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bryde's whale; Minke whale; Sei whale; Sperm whale; South Atlantic. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702010000500011 |
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| Gioia, Rosalinda; Macleod, Matthew; Castro-jimenez, Javier; Nizzetto, Luca; Dachs, Jordi; Lohmann, Rainer; Jones, Kevin C.. |
| A diel (24-h) cycle with daytime atmospheric concentrations higher than nighttime concentrations by a factor of 1.5-3 was observed for several low molecular weight polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in remote areas of the tropical South Atlantic during a cruise in October-November 2005. In contrast, high molecular weight PCBs and PAHs did not display diurnal variability. A model which has successfully explained diel variability of persistent organic pollutants (POPs) over land could not reproduce the observed diel cycle by considering variability in temperature, atmospheric OH radical concentrations, atmospheric boundary layer height and wind speed as causal factors. We used the model to conduct two bounding... |
| Tipo: Text |
Palavras-chave: Persistent organic pollutants (POPs); Diurnal cycle; Polychlorinated biphenyls (PCBs); Polycyclic aromatic hydrocarbons (PAHs); South Atlantic. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00645/75721/76676.pdf |
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| MUXAGATA,ERIK; BARBOSA,CARLA N.; AGOSTINI,VANESSA O.. |
| Abstract: Information about euphausiids in central South Atlantic Ocean is scarce; hence, we investigated species composition and distribution of euphausiids along a longitudinal transect in this region, with an emphasis on Thysanopoda. Zooplankton samples were collected from 44 stations during the first Transatlantic Commission (Brazil–Africa). Euphausiids comprised 21,390 individuals across larval stages (nauplius, calyptopis, and furcilia) and adults. Furcilia and adults were classified to species level when possible, with a total of 19 identified species. Overall, Euphausia species frequency of occurrence and abundance were highest in samples collected near the African coast, while Thysanopada species dominated near the Brazilian coast. Of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Euphausiids; South Atlantic; Thysanopoda astylata; Zooplankton. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000100621 |
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| Roberts, Jenny; Gottschalk, Julia; Skinner, Luke C.; Peck, Victoria L.; Kender, Sev; Elderfield, Henry; Waelbroeck, Claire; Riveiros, Natalia Vazquez; Hodell, David A.. |
| Explanations of the glacial-interglacial variations in atmospheric pCO(2) invoke a significant role for the deep ocean in the storage of CO2. Deep-ocean density stratification has been proposed as a mechanism to promote the storage of CO2 in the deep ocean during glacial times. A wealth of proxy data supports the presence of a "chemical divide" between intermediate and deep water in the glacial Atlantic Ocean, which indirectly points to an increase in deep-ocean density stratification. However, direct observational evidence of changes in the primary controls of ocean density stratification, i.e., temperature and salinity, remain scarce. Here, we use Mg/Ca-derived seawater temperature and salinity estimates determined from temperature-corrected delta O-18... |
| Tipo: Text |
Palavras-chave: South Atlantic; Density gradient; Ocean stratification; Last deglaciation; Atmospheric CO2. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00421/53276/54569.pdf |
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| MUTO,E. Y.; SOARES,L. S. H.; GOITEIN,R.. |
| The feeding habits of Rioraja agassizii (syn. Raja agassizii) and Psammobatis extenta (syn. Psammobatis glansdissimilis) of the South-eastern Brazilian coast were studied by means of stomach content analysis. The samples were obtained on eight seasonal oceanographic cruises, carried out between October 1985 and July 1987. The importance of each food item was evaluated on the basis of the Index of Relative Importance and the feeding similarity by Percentage of Similarity. The results indicated that both species are benthic feeders, preying mainly on Crustacea, especially Amphipoda, Caridea and Brachyura. Teleostei were also important for R. agassizii. Seasonal variation of the diet seems to be associated with the availability of the prey, whose distribution... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rajidae; Stomach content; Feeding habits; South Atlantic; Brazil. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71082001000200005 |
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| Wefing, Anne-marie; Arps, Jennifer; Blaser, Patrick; Wienberg, Claudia; Hebbeln, Dierk; Frank, Norbert. |
| High-precision U-series dating of scleractinian cold-water corals is a key chronological tool for studies of past environmental and climate conditions. Here, we tested and optimized an automated chemical extraction system (ESI prepFAST-MC equipped with an Eichrom TRU-resin chromatographic column) for its ability to purify U and Th isotopes for mass spectrometric U-series dating at the sub-‰ precision level. Chemical yields are constantly high, on average around 90% for both U and Th. Analytical blanks are comparable to manual purification (< 0.15 pg U, 0.15 pg Th for a typical sample of 50 mg) and memory effects due to the recycling of the column are mostly insignificant as the carry-over fraction is about 10− 5 for Th and 10− 3 for U isotopes. However,... |
| Tipo: Text |
Palavras-chave: U-series dating; PrepFAST-MC; Cold-water corals; South Atlantic; Angola; Past climate. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00409/52058/52761.pdf |
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| Bayon, Germain; German, Cr; Nesbitt, Rw; Bertrand, P; Schneider, Rr. |
| [1] Analysis of radiogenic isotopes in marine sediments can provide useful information on the provenance and transport of detrital material, directly relevant to paleoceanographic investigations. Here we show that the detrital Nd isotopic composition of recent SE Atlantic marine sediments matches the complex modern-day hydrography. In these same cores, glacial-interglacial isotopic variations are consistent with previous investigations (using different paleoceanographic proxies), which have shown that the relative influence of North Atlantic Deep Water (NADW) into the South Atlantic was reduced during glacial periods. In a novel departure, however, we also calculate the mass accumulation rates of terrigenous material delivered by each of Circumpolar Deep... |
| Tipo: Text |
Palavras-chave: Neodymium isotopes; Detrital fractions; South Atlantic; Deep water circulation; IMAGES; Marine geology and geophysics : marine sediments processes and transport; Oceanography : general : paleoceanography. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00000/10190/9912.pdf |
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| Menezes,Natália Matos de; Neves,Elizabeth Gerardo; Barros,Francisco; Kikuchi,Ruy Kenji Papa de; Johnsson,Rodrigo. |
| The morphology of sessile invertebrates, such as scleractinian corals, can be controlled by environmental and genetic mechanisms and, consequently, it is highly variable. Morphological variation has puzzled taxonomists by posing challenges to species classification within cryptic species complexes. The 'Atlantic Siderastrea Complex' is a suitable example. Because of overlapping diagnostic traits, the morphological interspecific limits of this group remain controversial and often resulted in doubtful synonyms. In addition, the recent identification of the Caribbean S. radians in the Southwestern Atlantic has revealed that intraspecific variation has been equivocally assessed. Traditionally, hierarchical categories of variation have been the criteria used to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Systematics; Siderastrea radians; Morphological variation; Biogeographic expansion; South Atlantic. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032013000100012 |
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| Abadie, Cyril; Lacan, Francois; Radic, Amandine; Pradoux, Catherine; Poitrasson, Franck. |
| As an essential micronutrient, iron plays a key role in oceanic biogeochemistry. It is therefore linked to the global carbon cycle and climate. Here, we report a dissolved iron (DFe) isotope section in the South Atlantic and Southern Ocean. Throughout the section, a striking DFe isotope minimum (light iron) is observed at intermediate depths (200–1,300 m), contrasting with heavier isotopic composition in deep waters. This unambiguously demonstrates distinct DFe sources and processes dominating the iron cycle in the intermediate and deep layers, a feature impossible to see with only iron concentration data largely used thus far in chemical oceanography. At intermediate depths, the data suggest that the dominant DFe sources are linked to organic matter... |
| Tipo: Text |
Palavras-chave: Iron isotopes; GEOTRACES; South Atlantic; Southern Ocean; Remineralization. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00367/47864/47859.pdf |
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| Thatcher,Vernon E.; Pereira Júnior,Joaber. |
| Kroyeria brasiliense sp. nov. from the shark, Galeorhinus vitaminicus de Buen, 1950, from Rio Grande do Sul, State, Brazil, is described on the basis of 14 adult females. The new species is superficially similar to Kroyeria deetsi Dippenaar, Benz & Olivier, 2000, but differs from it in the following characters. The maxillipeds of the new species are large and project well beyond the lateral margins of the cephalothorax. Those of K. deetsi are much smaller. The third endopodal segments of K. deetsi are twice as long as the second endopodal segments and are provided with prominent marginal denticles. The second and third endopodal segments of the new species are rounded, of similar length and lack teeth. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Copepod parasite; Kroyeriid; Southern Brazil; South Atlantic. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752006000400027 |
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| Registros recuperados: 38 | |
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