Summertime thermohaline structure off the Brazil Current Region between Santos (SP) and Rio de Janeiro (RJ)

Abstract

Within the scope of the MAR-14 Project, part of the Brazil-Germany Bilateral Agreement in Marine Sciences, an oceanographic survey aboard the R/V Victor Hensen was carried out in Brazilian coastal waters between Santos (23º56'S) and Rio de Janeiro (22º54'S), from January 15 to January 22,1991. In this article we report results of preliminary analyses of the hydrographic data collected with CTD, STD, Nansen bottles and XBT's. These preliminary results show intense stratification in the first 200 m depth, and the penetration of the Brazil Current deep into the continental shelf region. Two eddy-like features were detected. The first one, anticyclonic, was located in the northern part of the domain and confined to the uppermost 200 m. The second, a cyclonic vortex, was found a little to the southwest below 200 m and extending downwards to about 800 m depth. Water mass analyses based on T-S diagrams suggest that the interface between the South Atlantic Central Water (SACW) and the Antarctic Intermediate Water (AIW) is located at about 500 m depth. One important aspect of this study is that this was the first time a high resolution survey with a CTD probe was realized along the eastern Brasilian Coast, south of Cabo Frio.