WIND-FORCED SEA-LEVEL VARIABILITY ON THE SOUTHEAST BRAZILIAN SHELF

Coastal sea level data collected along the southeast coast of Brazil, from Cabo Frio to Cabo de Santa Marta, for the period August-November 1978 were examined, together with meteorological data for evidence of wind-forced, low-frequency fluctuations. A dominant 9- to 12-day perturbation in sea level, atmospheric pressure, and wind propagated equatorward from Cananeia and appeared to propagate poleward between Cananeia and the southernmost station A 6- to 7-day perturbation in sea level and wind propagated equatorward from the southernmost station, in agreement with the movement of cold fronts through the area. Sea level fluctuations in the central and northern portions of the bight for both 9- to 12- and 6- to 7-day bands were better correlated with winds located southward and earlier in time than with the local wind at the time of sea level measurement. Modeling of sea level response at Ubatuba for a period of 90 days, using the theory of barotropic continental shelf waves generated by wind forcing, presented results that were similar to the observed response.