- Estimate the alongslope and vertical distributions of the western boundary currents.

           For this purpose, we note that the domain located inshore of A17 is nearly closed to the south (estimated inflow of ~2 Sv between the Falkland Islands and Argentina, according to Saunders and King, 1995). Owing to volume conservation in isopycnal layers, and to diapycnal transports at the layer interfaces generally not exceeding 2 to 3 Sv, the meridionally integrated transport across the line also provides and estimate of the alongshore net flow between it and the coast. Here these alongshore transports are assimilated with those of the boundary currents themselves.

      - Estimate the wind-driven and thermohaline contributions to the alongshore transport distributions.

           Here also, the alongshore transports between A17 and the coast are used as estimates of the boundary current transports. At places, this provides only a crude approximation, as the widths of the boundary currents are different from the distance of the hydrographic line from the continental slope. This approach, however, allows us to take advantage of the high latitudinal resolution provided by A17.

      - Determine the lateral structure of the boundary flows.

           This was done by estimating the flows across the southern end of the meridional section and three transverse lines at locations (50°S, 35°S, 13°S, 10°N) representative of the subpolar, subtropical, and southern and northern subequatorial domains.