Physical-biological interactions within the mesoscale structures of the South Equatorial Current bifurcation northern branch

Abstract

Large-scale circulation in the South Atlantic Ocean is characterized by a large anticyclonic gyre, and the current that limits this gyre to the north is the South Equatorial Current (SEC). When the southern branch of the SEC reaches the Brazilian continental margin, this current bifurcates. The most known patterns regarding of the South Equatorial Current Bifurcation (SECBi) are large scale. The mesoscale patterns are best known in the southern branch of the SECBi, which is associated with the formation of the Brazil Current. There are no studies on the mesoscale activity associated with the northern branch of the SECBi or on the physical-biological interactions within these mesoscale structures. This work aims to verify if the chlorophyll a signal of the mesoscale structures associated to the SECBi northern branch that was found in satellite images is a result of the advection of organisms of the coast by the West Boundary Current, of the local production due to vertical quasi-geostrophic velocities, or submesoscale activity. (AU)