The Princeton Ocean Model (POM) was adapted to São Sebastião Channel (SSC) by nesting three numerical grids so as to study the seasonal changes of its circulation and thermohaline structure. Through monthly average conditions, the numerical model simulated reasonably the typical conditions of spring, summer, autumn and winter, filling the bottom channel with South Atlantic Central Water (SACW) in spring and in summer. In autumn and in winter this mass of water is not found, nevertheless its weaker signs appear in autumn, season in which the stronger signs of Tropical Water (never more than 50%) are found. Northeasterly winds on the Southeast Continental Shelf (SECS) grid are essential so that the SACW enters SSC. The bottom circulation obtained in SSC is essentially to northeast and associated to the intrusion of the SACW forced first by the northeasterly winds in SECS and second by the pressure force always bigger at the south entrance than in the north entrance and always bigger in summer than in winter. The superficial currents are southwestward, weakening in autumn and intensifying towards summer, with its maximum in this season.
Numerical modeling; thermohaline structure; currents
