An Explanation of Anomalously Large Reynolds Stresses Within the Convective Planetary Boundary Layer

Abstract

Anomalously large values of the Reynolds stress (downstream component) obtained from measurements analysed by Angell are explained as being associated with changes in velocity at the top of a deepening planetary boundary layer. The proposed explanation is tested both by a simple interfacial velocity-jump model, and by a detailed three-dimensional numerical model. A method of parameterizing the complicated vertical profiles of momentum flux is proposed for use within large scale, multi-level circulation models.