Summertime Coastal Currents in the Northeastern Gulf of Mexico

Abstract

Observations of currents and temperature at a mooring on the 18 m isobath, 30 km south of the Florida shoreline, are discussed for the 31-day period 15 August?15 September 1978. Tidal currents, having average amplitudes of ?10 cm s?1, account for 85% of the observed kinetic energy. Low-frequency currents with maximum speeds of ?10 cm s?1 appear to be at least partly driven by local wind-stress events of magnitude ?0.2 dyn cm?2. Frictional effects give rise to a veering with depth (in the Ekman sense) of both the low-frequency flow and the energetic, counterclockwise-rotating twice-daily tidal currents. Propagation of both the tidal signal and low-frequency coastal sea-level fluctuations (amplitudes <5 cm) is westward through the study area.