Evaluating models of the neutral, barotropic planetary boundary layer using integral measures: Part II. Modelling observed conditions

The steady-state, horizontally homogeneous, neutral, barotropic case forms the foundation of our theoretical understanding of the planetary boundary layer (PBL). While simple analytical models and first-order closure models simulate atmospheric observations of this case well, more sophisticated models, in general, do not. In this paper we examine how well three higher-order closure models, E - epsilon - l, E - l, and LRR - l, which have been especially modified for PBL applications, perform in predicting the behaviour of the cross-isobaric angle alpha(0), the geostrophic drag coefficient C(g), and the integral of the dissipation rate over the boundary layer, as a function of the surface Rossby number Ro. For comparison we also examine the performance of three first-order closure mixing-length models, two proposed by A. K. Blackadar and one by H. H. Lettau, and the performance of the standard model for second-order closure and a modification of it designed to reduce the overprediction of turbulence in the upper part of the boundary layer.