Show simple item record Piola, Alberto Möller Junior, Osmar Olinto Guerrero, Raúl Campos, Edmo José Dias 2012-11-13T11:26:38Z 2012-11-13T11:26:38Z 2008
dc.identifier.citation PIOLA, Alberto et al. Variability of the subtropical shelf front off eastern south America: winter 2003 and summer 2004, Continental Shelf Research, v. 28, p. 1639-1648, 2008. Disponível em: <>. Acesso em: 1 jun. 2012. pt_BR
dc.description.abstract Hydrographic data collected during surveys carried out in austral winter 2003 and summer 2004 are used to analyze the distributions of temperature (T) and salinity (S) over the continental shelf and slope of eastern South America between 271S and 391S. The water mass structure and the characteristics of the transition between subantarctic and subtropical shelf water (STSW), referred to as the subtropical shelf front (STSF), as revealed by the vertical structure of temperature and salinity are discussed. During both surveys, the front intensifies downward and extends southwestward from the near coastal zone at 331S to the shelf break at 361S. In austral winter subantarctic shelf water (SASW), derived from the northern Patagonia shelf, forms a vertically coherent cold wedge of low salinity waters that locally separate the outer shelf STSW from the fresher inner shelf Plata Plume Water (PPW) derived from the Rı´o de la Plata. Winter T–S diagrams and cross-shelf T and S distributions indicate that mixtures of PPW and tropical water only occur beyond the northernmost extent of pure SASW, and form STSW and an inverted thermocline characteristic of this region. In summer 2004, dilution of Tropical water (TW) occurs at two distinct levels: a warm near surface layer, associated to PPW–TW mixtures, similar to but significantly warmer than winter STSW, and a colder (T 16 1C) salinity minimum layer at 40–50m depth, created by SASW–STSW mixtures across the STSF. In winter, the salinity distribution controls the density structure creating a cross-shore density gradient, which prevents isopycnal mixing across the STSF. Temperature stratification in summer induces a sharp pycnocline providing cross-shelf isopycnal connections across the STSF. Cooling and freshening of the upper layer observed at stations collected along the western edge of the Brazil Current suggest offshore export of shelf waters. Low T and S filaments, evident along the shelf break in the winter data, suggest that submesoscale eddies may enhance the property exchange across the shelf break. These observations suggest that as the subsurface shelf waters converge at the STSF, they flow southward along the front and are expelled offshore, primarily along the front axis. pt_BR
dc.language.iso eng pt_BR
dc.rights restrict access pt_BR
dc.subject Shelf fronts pt_BR
dc.subject Water masses pt_BR
dc.subject Water mixing pt_BR
dc.subject Seasonal variations pt_BR
dc.subject Southwest Atlantic pt_BR
dc.title Variability of the subtropical shelf front off eastern south America: winter 2003 and summer 2004 pt_BR
dc.type article pt_BR
dc.identifier.doi 10.1016/j.csr.2008.03.013 pt_BR

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