The north Brazil undercurrent and the wind driven hydrodynamics in Japaratuba submarine canyon, Brazil

Abstract

The circulation induced by the wind and the North Brazil Undercurrent (NBU) in and surrounding the Japaratuba submarine canyon on the continental shelf of the basin of Sergipe and Alagoas is described using numerical modeling. The numerical simulations were implemented to determine the canyon influence in the local hydrodynamics and in the volume flow normal to the coast, considering several different scenarios, including a homogeneous and stratified fields of temperature and salinity. Northeast and East winds favor an upward flow in the canyon, while Southeast and South winds privilege subsidence. Winds parallel to the coast cause greater volume flow in the canyon section: 40° winds (relative to true the North, parallel to the coast) caused the highest upward flow, while winds from 215° to 220° caused the highest subsidence. On the other hand, the NBU favors subsidence motion and seems to predominate over the wind forcing.