Oceanographic conditions of the continental slope and deep waters in Santos Basin: the SANSED cruise (winter 2019)

Abstract

This work describes the circulation over the continental slope and the São Paulo Plateau in the Santos Basin during the SANSED winter 2019 survey. The cruise consisted of four legs in the period between June, 11 and August, 03 2019. The observed circulation is dominated by the Atlantic southwestern boundary current regime and remotely-generated anticyclones and cyclones. The former is composed by the Brazil Current, the Intermediate Western Boundary Current and their mesoscale meanders; the latter are 300km vortical rings with origin in the eastern side of the South Atlantic Basin. A Lagrangian scheme applied over satellite altimeter maps indicate that the origin of these rings is primarily the Cape Basin off South Africa. The interaction between the boundary currents, their cyclonic meanders, and the anticyclonic rings is complex, and varies widely. During the SANSED winter 2019 survey period, three anticyclones interacted with the Brazil Current, instabilizing it, forming dipoles with the current cyclonic meanders, leading to their downstream propagation. Ancienter cyclonic eddies within Santos Basin may interfere with the propagation of the large anticyclones further south. In addition, the continuous arrival of remotely-originated anticyclones, the larger portion over the São Paulo Plateau presented a tendency of counter-clockwise circulation during the whole cruise period.

Modeling the larvae dispersion of sun coral in the Brazil current off Cape Frio: A cyclonic eddy scenario

“…In the first 15 days of larval experiment, the CFE growth is quasi-stationary and as it increases it is advected southward by the mean water flow due to the Brazil Current. As mentioned by [ 75 ], the offshore displacement of the CFE is also intricately intertwined with complex interactions involving other eddies formed within the region, as well as those that arrived in the region. This pattern is illustrated in Fig 6 , where a high density of red markers at 24.2°S and 42°W represents the initial growth in a stationary phase.…”

Santos Basin continental shelf morphology, sedimentology, and slope sediment distribution

“…The shallow and deep-water meteoceanographic processes that influence Santos Basin geomorphology and sediment composition, like waves, currents, and water masses, are thoroughly discussed by Dottori et al (2023) and Silveira et al (2023).…”

Subsidies for ecosystem-based management in an offshore oil and gas exploration area, Santos Basin, Brazil

“…They showed that the continental shelf can be divided into two sectors with distinct characteristics in relation to the São Sebastião areas: (1) in the Southwestern sector, the presence of Subtropical Shelf Water (STSW) modulates the hydrographic parameters, and (2), the Northeastern sector where the uplifting of the South Atlantic Central Water was the dominant process (Dottori et al, 2023). On the slope and São Paulo plateau, hydrographic circulation is dominated by both the Atlantic southwestern boundary (ASB) current regime and the remotely generated eddies (Silveira et al, 2023). The Brazilian Current, the Intermediate Western Boundary Current, and their mesoscale meanders form the ASB, whereas the eddies originate on the eastern side of the South Atlantic Basin.…”