Wave-turbulence scaling in the ocean mixed layer

Abstract

Microstructure measurements were collected using an autonomous freely rising profiler under a variety of different atmospheric forcing and sea states in the open ocean. Here, profiles of turbulent kinetic energy dissipation rate, epsilon, are compared with various proposed scalings. In the oceanic boundary layer, the depth dependence of epsilon was found to be largely consistent with that expected for a shear-driven wall layer. This is in contrast with many recent studies which suggest higher rates of turbulent kinetic energy dissipation in the near surface of the ocean. However, some dissipation profiles appeared to scale with the sum of the wind and swell generated Stokes shear with this scaling extending beyond the mixed layer depth. Integrating epsilon in the mixed layer yielded results that 1% of the wind power referenced to 10 m is being dissipated here.