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Nearly all operational ocean models use air-sea fluxes and the ocean shear and stratification to estimate upper ocean boundary layer mixing rates. This approach implicitly parameterizes surface wave effects in terms of these inputs. Here we test this assumption using parallel experiments in a lake with small waves and in the open ocean with much bigger waves. Under the same wind stress and adjusting for buoyancy flux, we find the mixed layer average turbulent vertical kinetic energy in the open ocean typically twice that in the lake. The increase is consistent with models of Langmuir turbulence, in which the wave Stokes drift, and not wave breaking, is the dominant mechanism by which waves energize turbulence in the mixed layer.Applying these same theories globally, we find enhanced mixing and deeper mixed layers resulting from the inclusion of Langmuir turbulence in the boundary layer parameterization, especially in the Southern Ocean.

Item Type:	Refereed Article
Keywords:	Langmuir circulations, mixing, ocean boundary layer, surface waves, turbulence
Research Division:	Engineering
Research Group:	Fluid mechanics and thermal engineering
Research Field:	Turbulent flows
Objective Division:	Environmental Management
Objective Group:	Marine systems and management
Objective Field:	Measurement and assessment of marine water quality and condition
UTAS Author:	Hemer, M (Dr Mark Hemer)
ID Code:	119207
Year Published:	2014
Web of Science® Times Cited:	90
Deposited By:	NC Maritime Engineering and Hydrodynamics
Deposited On:	2017-07-27
Last Modified:	2017-11-15
Downloads:	133 View Download Statistics