9420641 This analysis of the dynamics of a stable atmospheric boundary layer is based on a history of antarctic katabatic wind studies and the principal investigator's work on boundary layer dynamics at South Pole Station. Several hypotheses have been advanced to explain a number of consistently observed features of katabatic winds. These include cold drainage flows driven by radiative cooling, warm surface temperatures, and downward mixing of cold air without depleting the negative buoyancy driving the flow. These hypotheses, reasonable when considered individually, have not been proven quantitatively in an integrated manner. This study will use high resolution models to simulate these flows in realistic topography, using conditions derived from the fairly extensive number of analytical studies that currently exist in the published literature. A regional hydrostatic model containing a high resolution boundary layer will be used to study relationships among the occurrence and strength of these events, the synoptic setting, regional radiative cooling rates, and regional geomorphological characteristics. A very high resolution compressible model will be applied to a single valley to simulate details of the flow's evolution, interaction with topography, and exchange of energy within the atmosphere and with the underlying surface. ***
