Mass transport across a temperature inversion

Vertical transport of mass both within and across the interface of the west coast temperature inversion is discussed. The vertical transport is ascribed to internal gravity waves. Although usually dynamically stable, transient waves moving through a layer of strong vertical shear of the horizontal wind produce extensive horizontal mixing near their crests, resulting in a vertical pumping of mass. The apparent vertical diffusion coefficient is not insignificant for large Richardson number, although it decreases with increasing Ri.