Ocean Dynamics

, Volume 57, Issue 2, pp 151–156 | Cite as

On leakage of energy from turbulence to internal waves in the oceanic mixed layer

Original paper


In this paper, we address the question of energy leakage from turbulence to internal waves (IWs) in the oceanic mixed layer (OML). If this leakage is substantial, then not only does this have profound implications as far as the dynamics of the OML is concerned, but it also means that the equation for the turbulence kinetic energy (TKE) used in OML models must include an appropriate sink term, and traditional models must be modified accordingly. Through comparison with the experimental data on grid-generated turbulence in a stably stratified fluid, we show that a conventional two-equation turbulence model without any IW sink term can explain these observations quite well, provided that the fluctuating motions that persist long after the decay of grid-generated turbulence are interpreted as being due to IW motions generated by the initial passage of the grid through the stably stratified fluid and not during turbulence decay. We conclude that there is no need to postulate an IW sink term in the TKE equation, and conventional models suffice to model mixing in the OML.


Turbulence Turbulent mixing Oceanic mixed layer Stably stratified fluid Internal waves Turbulence kinetic energy 



L.H.K. thanks the ONR for the support for this work through the ONR grant N00014-06-10287. L.H.K. is very thankful to George L. Mellor for pointing out that the IW fluctuations observed in the DM experiments could have been generated at the very beginning by the initial passage of the grid.


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Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Department of Aerospace Engineering Sciences, CB 431University of ColoradoBoulderUSA
  2. 2.Department of MeteorologyFlorida State UniversityTallahasseeUSA

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