Small‐scale shear measurements during the fine and microstructure experiment (Fame)

The turbulent kinetic energy dissipation rate ε is estimated from measurements of small‐scale shear taken with a vertical profiler during the Fine and Microstructure Experiment (Fame). Typical profiles of ε are presented for the different oceanographic regions sampled, the Gulf Stream, a mid‐Sargasso site, and locations within and without the 1000 fathom (∼2000 m) contour about the island of Bermuda. Heavily averaged values of ε are presented as a function of mean Väisälä frequency , a fundamental scaling parameter for the oceanic internal wave field. A dependence of is found for an ensemble of stations near Bermuda; functional dependence for an ensemble of stations at the mid‐Sargasso site is less clear, with results exhibiting an undesirable sensitivity to infrequent large events. Dissipation is found to increase as the island of Bermuda is approached from any direction: the density of measurements is insufficient to determine any azimuthal variation resulting from the anisotropic mean flow field about the island at the time. A set of three profiles across the Gulf Stream suggests that this is not a region of abnormally high dissipation, a conclusion supported by previous and concurrent measurements of temperature finestructure and microstructure.