The LANS-alpha turbulence model in ocean modeling

The Lagrangian-Averaged Navier-Stokes alpha (LANS-alpha) model is a turbulence model that improves the resolution of small-scale features. Simulations using LANS-alpha in the POP ocean model look like higher resolution simulations of standard POP in statistics like kinetic energy, eddy kinetic energy, and potential temperature fields. The LANS-alpha model accomplishes this improvement through an additional nonlinear term and a smoothed advecting velocity.

I will discuss my implementation of LANS-alpha in POP, and results using an idealized channel domain that invokes the baroclinic instability. I will also compare LANS-alpha to other turbulence models like eddy viscosity and Gent-McWilliams isopycnal tracer mixing.