A Study of the Bottom Boundary Layer of the Florida Current

Abstract

This is a report of an experiment designed to study the bottom boundary layer of the Florida Current at a representative site in the Straits of Florida. The objectives of the experiment were 1) to determine the bottom frictional stress τ0, and 2) to determine whether the bottom boundary layer is a turbulent Ekman layer. A typical value of the bottom stress τ0 was found to be ~0.2 dyn cm−2. A mean veering of ~10° in the correct sense was observed in the logarithmic layer. No mean veering was observed above the logarithmic layer; this is believed to be a consequence of the strong modulation of the bottom current by the diurnal tide. The implication of τ0≈0.2 dyn cm−2 is considered in a simplified model of the Gulf Stream current system; this analysis suggests that, dynamically, the role of bottom friction is rather small.