Turbulence in a stably stratified shear flow - A progress report

A preliminary investigation of an evolving stably stratified uniform gradient turbulent shear flow has been conducted in a ten-layer, salt-stratified water channel. Simultaneous single-point measurements of the mean and fluctuating density and the horizontal and vertical velocities were made over a wide range of downstream positions. This study is a first attempt to extend the stratified, unsheared grid-generated turbulence study reported in Stillinger, Helland and Van Atta (1983) to a stratified, uniform shear flow. A primary objective of the present study is to generalize the dynamics described by the length scale models developed in SHV by the addition of a uniform shear in order to obtain criteria which can be compared with more general atmospheric and oceanic measurments. Other objectives are the examination of the dependence of turbulent diffusivity, energy, and length scales on the gradient Richardson number, refining and extending the earlier work of Webster (1964).