This project is to conduct several laboratory experiments of long nonlinear internal waves in laterally inhomogeneous environments. Long internal waves are ubiquitous features on continental shelves. Field studies indicate that wave instabilities may cause significant vertical mixing. The proposed research is designed to examine several processes which can lead to wave instability and breaking and thus promote mixing. The first experiment will investigate the shoaling of an internal solitary wave in a two- layer system. The second considers the interaction of a internal solitary wave with a horizontally varying density field. The third experiment extends the work on shoaling to include a continuously rather than uniform lower layer. All three situations are geophysically relevant. The objective is an improved understanding of the processes leading to instability and dissipation of long internal waves, and how these waves may help maintain or enhance mixing on continental shelves.
