The skewness of temperature derivatives in oceanic boundary layers

Abstract

The skewness of the derivative of temperature measured by sensors in the upper-ocean boundary layer in convective conditions has been measured and is observed to have a sign opposite to that found in conditions of stable heating. This is consistent with observations in the atmospheric boundary layer. High resolution measurements in the benthic boundary layer on a continental rise show a variation of skewness during the M "SUB 2" tidal cycle (which dominates the motion), with negative skewness, consistent with conditions favouring convection, occurring during the upslope phase of the motion. The observations are compared with laboratory studies of the reflection of internal waves from a slope. It is suggested that information about the gross features of a turbulent oceanic boundary layer flow may be derived from relatively simple measurements. (A)