Mixed Layer Turbulence and Entrainment

University Of Washington, Seattle WA

Investigators

Abstract

0117411 D'Asaro/UW This is a project intended to analyze data from two deployments of Lagrangian floats in the surface mixed layer. One deployment consisted of three floats and the other, two. It is anticipated that additional data will come from an ONR-funded experiment in 2002. The intention is to look at the relation between turbulent kinetic energy in the mixed layer, the structure of mixed layer turbulence, wind stress, and surface wave activity. The dependence of entrainment rate on wind and surface waves will also be studied. The approach used involves examining spectra of w, du/dz, and density perturbations at different levels in the mixed layer (near the surface, in the interior, and near the base of the mixed layer) where different dynamics are expected to prevail (surface waves, homogeneous turbulence, internal waves). The project also includes an attempt to examine vertical heat and salt budgets. As part of this project, numerical simulations of the mixed layer, Large-Eddy Simulations will be made. These simulations will be compared to data derived from the floats with the aim of testing new parameterizations of the effects of surface waves and of the influence of stratification on mixed-layer turbulence.