Observations of Regional Topographically-Induced Wind Systems in Natal

Abstract

Observations are presented to show the occurrence of boundary layer oscillations in the form of widespread and large-scale topographically-induced mountain-plain and plain-mountain winds over the deeply dissected eastern plateau slopes of Natal. By night, extensive northwesterly advection of cool air occurs between the Drakensberg escarpment zone and the coast; by day, the flow is reversed and southeasterly inland advection is characteristic of clear, fine conditions. The distinctive temporal and spatial characteristics of regional winds correspond in a near-ideal manner to those expected in a thermodynamically direct circulation caused by the diurnal cycle of insolation.