Coupled Physical Numerical Models of the Nonlinear Interaction between Coastal-Trapped Waves, Mean Current and Complex Topography

Arizona State University, Scottsdale AZ

Investigators

Abstract

0137197/Boyer This project seeks to understand how coastally trapped waves (CTWs) interact with baroclinic currents and topography (canyons and ridges). Potential regimes where such interactions may be important are the Great Australian Bight and the Black Sea. Motivated by recent model results that suggest that a barotropic shelf wave in a retrograde current can generate strong mesoscale vortices and cross-shelf exchange after undergoing topographic scattering, the project will use laboratory experiments to see if scattering leads to strong mesoscale motion. Laboratory experiments will also be used to look for subcritical and supercritical transitions in CTW propagation. The main experimental tool will be laboratory experiments in a rotating tank in homogeneous, two-layer, and linearly stratified configurations. The tank will be fitted with both smooth shelf-slope topography, and abrupt topography such as canyons and ridges. Background currents will be introduced by impulsively varying the rotation rate or by introducing a source-sink flow. The laboratory experiments will be complemented with numerical modeling using modern coastal circulation models. Data from the laboratory experiments will be used to validate the numerical models and then the numerical models will be used to extend results to more oceanic regimes.