*** 9725263 Parish This project is a study of how the cold and intense surface winds that flow down from the antarctic continental ice sheet (the so-called katabatic winds) interact with the larger scale pressure gradients that result from the passage of synoptic weather systems around the antarctic perimeter. Recent research has shown that while katabatic winds play an important role in the atmospheric mass, heat, and momentum budgets at high southern latitudes, their interaction with synoptic weather systems is complex and unclear, with different studies leading to different conclusions. This study will make use of a series of observations on the structure of the antarctic troposphere that resulted from an international effort to assemble the most complete, detailed, and accurate data set possible for several prescribed observation periods in 1994 and 1995 - the First Regional Observing Study of the Troposphere (FROST). State-of-the-art numerical models will complement these observations: the National Center for Atmospheric Research/Pennsylvania State University MM5 model, the Colorado State University RAMS model, and the University of Wisconsin NMS model. Preliminary work has indicated that these models will be capable of realistically resolving the antarctic environment. Numerical simulations of cyclonic systems along the coast of East Antarctica will be conducted to resolve the response of the katabatic wind regime. Extensive evaluation of model results will take place in order to determine the magnitude of individual terms in the equations of motion that are affected by the synoptic systems, the katabatic winds, and the underlying terrain. It is expected that this work will provide new information and a greater understanding of the connections of antarctic weather systems to the circulation of the free atmosphere both at higher altitudes and lower latitudes, and to global atmospheric processes. ***
