Figure 6: Meridional distribution of the alongshore transports inshore of A17 (positive southward) in 9 isopycnal layers representative of the major water masses. FC: Falkland Current; DWBC: Deep Western Boundary Current; BC: Brazil Current; NBUC: North Brazil Undercurrent. UNADW, MNADW, LNADW give the classical division of the NADW into its upper, middle, and lower components

The breakdown of the alongshore transports per water masses (Fig 6) gives the vertical and meridional arrangement of the main boundary currents. At the southern end of the section, the barotropic Falkland Current stands out, slightly wider in the two lower layers (the negative peak at 45°S was an eddy).

The Brazil Current originates at 14°S in the upper layer, a southward displaced latitude probably due to the averaging between A17 and the coast. It is progressively reinforced by deeper contributions toward the south. At 28°S, the disappearance of the northward flowing layer of AAIW which separates the southward flows of SACW and NADW farther north causes a thickness increase of the Brazil Current, down to the base of the MNADW. The northward intensification of the NBUC is particularly pronounced to the north of 5°S through the adjunction of the central branch of the South Equatorial Current.

The southward Deep Western Boundary Current extends downward to the bottom around 15°S-25°S. Although the uncertainties render the transport estimates of the deepest layer not significantly different from zero in this region, this observation corroborates previous results (e.g. Hogg and Owens, 1999; Weatherly et al., 2000), and suggests an eastward shift of the northward boundary current of AABW at these latitudes.