Comments on “Turbulence Closure, Steady State, and Collapse into Waves”

Abstract

Two-equation models are being increasingly used to model turbulence in geophysical flows. A salient aspect of these flows is the stable gravitational stratification, which implies that turbulent fluctuations can generate internal waves that drain energy from turbulent eddies. This energy is not available for mixing, and therefore this transfer of energy from turbulence to internal waves has strong implications to mixing in the atmospheric boundary layer and the oceanic mixed layer. How to parameterize energy leakage to internal waves in turbulence models has been the subject of many studies, most recently by Baumert and Peters. This comment is an attempt to critique their work and to explore alternative options.