Airflow over a two-dimensional escarpment. II: Hydrostatic flow

Pitts, R.O. and Lyons, T.J. (1990) Airflow over a two-dimensional escarpment. II: Hydrostatic flow. Quarterly Journal of the Royal Meteorological Society, 116 (492). pp. 363-378.

PDF - Published Version Download (5MB)

Abstract

Hydrostatically dominated forced flow over the asymmetric topography of the Darling Scarp, Western Australia, is modelled using a hydrostatic numerical mesoscale model and compared with observations. Simulations reproduce the essential features of wave overturning and the development of a shooting hydraulic flow. This response is dependent on the wind profile but not on the existence of a critical level. the high backsheared environment leads to a high ratio of the Brunt-Väisälä frequency to wind speed throughout the profile, resulting in short wavelengths, high nonlinearity and overturning. With the ratio of the halfwidth of the topography to the boundary-layer depth being small, the flow fields are shown to be sensitive to the boundary layer.