Kevin Lamb | Applied Mathematics, University of Waterloo
The Strange World of Internal Gravity Waves in the Ocean
Internal gravity waves exist in density stratified fluids where they are driven by gravitational restoring forces acting on vertically displaced fluid. They are ubiquitous and important features in the interior of the atmosphere, oceans and stratified lakes. While they have many properties in common with surface water waves, an important difference is that they can propagate both horizontally and vertically. The latter gives rise to anisotropic behaviour in the vertical plane because gravity makes the vertical a special direction. As a consequence these waves have a number of counter-intuitive and surprising properties. These waves are often highly nonlinear giving rise, for example, to internal solitary waves commonly observed in the coastal ocean, and nonlinear interactions among waves that play a crucial role in the transfer of energy from large to small scales. In this talk I will provide an introduction to internal gravity waves and focus on internal solitary waves and their brethren and on the role of internal waves in deep ocean mixing.