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 τ 0 , and 2) to determine whether the bottom boundary layer is a turbulent Ekman layer. A typical value of the bottom stress τ 0 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 τ 0 ≈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.