A barotropic model of the currents off SE South America

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Abstract
A depth‐averaged numerical model with 13‐km grid resolution was applied to the region defined by the 55°W meridian, the 56°S parallel and the southeast coast of South America. This region is characterized by high biological productivity, and by an exceptional tidal regime that interacts with the subpolar Falkland/Malvinas (FM) current. The results presented contribute to the development of an ecohydrodynamic system intended for the study of the implications of increasing exploitation of natural resources in the region. Detailed tidal charts show the propagation on the continental shelf of tidal waves related to clockwise amphidromes in the South Atlantic, indicating the occurrence of resonance. The averaged velocity field is dominated by the FM current, although tidal residuals around headlands are significant on the Patagonian coast. In contrast, “snapshots” describe the interaction between the tides and the FM current, where the flow patterns displayed are expected to influence the population dynamics of biological species. The mean wind stress induces strong currents and a large anticlockwise circulation cell northeast of Tierra del Fuego. The strong tidal and FM currents generate shelf sea fronts whose locations, revealed by contours of the Simpson‐Hunter parameter, are related to major fishing grounds. Because of the lack of velocity measurements in the region, the FM and wind‐driven currents simulated by the model should be taken as experimental results until proper comparisons with observations can be made.