Contribuição ao estudo das correntes de superfície sobre a plataforma continental do estado de São Paulo, Brasil (Lat. 24º00'S - 25º10'S até Long. 45º40'W) Contribution to the study of surface currents on the continental shelf of São Paulo state, Brasil (Lat. 24º00'S - 25º10'S to Long. 45º40'W)

Abstract

Durante a viagem de julho-agosto de 1977, do Sub-Projeto "Hidrodinâmica Costeira" (Projeto FINEP), foram efetuados lançamentos de garrafas-de-deriva diante do litoral paulista para o estudo da circulação em superfície. De 580 garrafas, foram recuperadas 54 ou seja, 9,3%. As garrafas encontradas ao sul, algumas apos percursos longos, revelaram terem sido transportadas por uma corrente maior nessa direção - a Corrente do Brasil. Outras, lançadas mais próximas a costa (± Long. 046º10'W para oeste nesta área), derivaram em uma corrente mais forte para o norte (NW, NE). As velocidades dessas transportadas nessa direção, eram mais elevadas (Drift bottles were released during the Project "Coastal Eydrodinamics" (FINEP) in July-August 1977, in front of the coast of São Paulo State, in order to study the surface circulation of this area. Of 580 bottles launched 54 (9,3%) were recovered. 63% were found at SW and 37% at NW and NE. Part of the bottles performed long routes southwards revealing the presence of the Brazil Current. Bottles launched near the coast (± Long. 046º10'W to the west) were driven by a stronger current northwards, presenting velocities higher than of those which drifted southwards. These facts seem to confirm that in the winter months the Brazil Current flews nearer the coast, forming meanders and eddies which retard the flew of the current. The rotating currents observed at the fixed station (Lat. 25º01'S-Long. 045º42'W) would explain the recovery of bottles from the same station in opposite directions. Those found at NW and NE, released east of Long. 046º00'W, performed their routes after a longer period of time; they have remained a longer time in the rotating current The more frequent winds, blowing from NE and NNE will explain the greater number of recoveries at SW of the releasing station, while stronger winds from SW would be, in part, responsible for the greater velocity of the current northwards.