Speaker: Pascale Lelong, Senior Research Scientist, Northwest Research Associates
Title:
Unraveling the Secrets of the Oceanic Submesoscale: An Applied Mathematician's Perspective
Time: 2:30 PM, Thursday, 5/10/07
Abstract:
My research focuses on the physics of submesoscale oceanic fluid flows. The submesoscales span horizontal scales of .1-10km and vertical scales on the order of 1-100m. They are the intermediate spatial scales that bridge the regime of large, energy-carrying motions such as currents or mesoscale eddies such as Gulf Stream rings, and the isotropic turbulent regime at which energy is dissipated. Submesoscale motions include inertia-gravity waves, small-scale vortices and rotating/stratified turbulence, yet detailed knowledge about the interactions between these components remains largely speculative, due to the limited number of direct observations.
A good dynamical understanding of the submesoscale regime is crucial to many different problems that range from being able to predict pollutant dispersal in coastal regions, to atmosphere/ocean weather prediction, and global climate change.
The governing equations are a set of three-dimensional, nonlinear, coupled partial differential equations (the Navier-Stokes equations + two diffusion equations). Analytical techniques used in conjunction with numerical techniques have proven invaluable in improving our knowledge of the oceanic submesoscale.
I will focus on two problems. The first involves trying to parameterize the observed submesoscale lateral dispersion of a passive tracer in the ocean. The second invokes multiple scale perturbation methods to understand the interactions between tidal motions and an eddy field.
Everyone welcome!