Authors: Naoki Furuichi Toshiyuki Hibiya Yoshihiro Niwa
Publish Date: 2012/02/03
Volume: 68, Issue: 2, Pages: 285-294
Abstract
Large eddy simulation LES of the resonant inertial response of the upper ocean to strong wind forcing is carried out the results are used to evaluate the performance of each of the two secondorder turbulence closure models presented by Mellor and Yamada Rev Geophys Space Phys 20851–875 1982 MY and by Nakanishi and Niino J Meteorol Soc Jpn 87895–912 2009 NN The major difference between MY and NN is in the formulation of the stability functions and the turbulent length scale both strongly linked with turbulent fluxes in particular the turbulent length scale in NN unlike that in MY is allowed to decrease with increasing density stratification We find that MY underestimates and NN overestimates the development of mixed layer features for example the strong entrainment at the base of the oceanic mixed layer and the accompanying decrease of sea surface temperature Considering that the stability functions in NN perform better than those in MY in reproducing the vertical structure of turbulent heat flux we slightly modify NN to find that the discrepancy between LES and NN can be reduced by more strongly restricting the turbulent length scale with increasing density stratificationThe authors express their gratitude to two anonymous reviewers for their invaluable comments This research was supported by the Innovative Program of Climate Change Projection for the 21st Century KAKUSHIN program The numerical experiments were carried out using Earth Simulator under support of the Independent Administrative Institution Japan Agency for MarineEarth Science and Technology JAMSTEC
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