Effects of shear, stability and valley characteristics on the destruction of temperature inversions.

Abstract

A dry two-dimensional version of the Colorado State Cloud/Mesoscale Model was used to study the morning inversion destruction cycle in a variety of deep mountain valley configurations. Eleven simulations were run to examine the effects of valley width, surface heating rate, wind shear above the valley, valley orientation, sidewall slope, initial stability and variable surface albedo on the evolution of the daytime boundary layer in the valley. All simulations show that the initial inversion layer is destroyed by a combination of three processes; a growing surface based neutral layer over the valley floor, the destabilization of the stable air mass by the recirculation of air warmed over the slopes and the descent of the inversion top by the transport of air beneath the stable layer out of the valley in the slope flows.- from Authors