Physical Properties of Turbulent Benthic Boundary Layers Generated by Internal Waves

Abstract

Physical properties of active turbulent benthic boundary layers (TBBL) generated by basin scale internal waves were studied within a Northern hemisphere thermally stratified lake. A microstructure profiler was used to measure the nature of the turbulence within the TBBLs while a series of thermistor chains were used to monitor the thermal structure of the lake. It was observed that a wind-driven anticlockwise diurnal-period vertical mode one Kelvin wave generated large scale motions within the water column, and that the interactions between this wave and the sloping lakebed induced TBBLs. A simple model, based on potential energy change and boundary shearing, was shown to describe the mean TBBL thickness.