Effects of Submarine Canyon Topography On Spin-up Over The Continental Shelf

摘要

The spin-up of homogeneous and stratified fluids are investigated in a rotating cylindrical tank containing a smooth valley-like interruption in an otherwise axisymmetric topography. The laboratory setup is designed to mimic a submarine canyon cutting into the topography of the coastal ocean. The forcing is induced by varying the rotation rate of the tank. An axisymmetric (canyon-free) case is used as a benchmark and results from these laboratory experiments are compared to theoretically predicted spin-up rates. A solution to an Ekman layer in a homogeneous fluid over a steep slope is compared to laboratory results. For the stratified scenario, Ekman layer arrest occurs slowly as other dynamics are clearly present at early time. It is found that the introduction of a submarine canyon to the system accelerates spin-up rates, especially in the stratified system. Radially outward flow present in the canyon as a result of vortex stretching enhances classical spin-up mechanisms.