This award will support collaborative research between Dr. Donald Boyer, Arizona State University, and Dr. Gabriel Chabert d'Hieres, Institut de Mecanique de Grenoble, France. This research seeks to investigate the nature of the flow of homogeneous and two-layer rotating flows along model coastlines (or sloping floors in the deep ocean), including the interaction of such flows with topography. The modeling parameters for this system include the Rossby, Ekman and Burger numbers, the slope of the shelf along the coastline and geometric parameters characterizing the topography. Primary consideration will be given to such cases in which the Burger number is small, so that the effects of stratification can be neglected. The research will include laboratory experiments and analytical and numerical quasigeostrophic models. The laboratory investigations are to be conducted in the 13 meter diameter rotating tow tank of the Institut de Mecanique, Grenoble, France. This facility permits experiments with shelf slopes approximately one order of magnitude smaller than those on more conventional turntables (i.e. one to two meters in diameter) and thus allows one to more closely simulate this parameter for possible oceanic applications. The initial laboratory experiments will concentrate on understanding the background flow for the case of along-shore currents in which no obstacle is present and for which the shoreline is either on the left or on the right. The interaction of these background flows with topography will then be addressed. Particular attention will be focused on the conditions for which such phenomena as blocking, eddy shedding and trapped Rossby waves occur. The results of this research will contribute to the understanding of basic features of topographic effects on oceanic currents along sloping surfaces. The Grenoble facility is unique and the experience gained in this project will be valuable for the further development of a similiar facility in the U.S.
