This research was sponsored by the National Science Foundation (Grant DMS-785 0723757) and Office of Naval Research (Grant N00014-08-1-0597). Computations were performed on the supercomputers Bluefire at NCAR and Thresher, Trestles, and Gordon at SDSC. We appreciate Dr. Leonel Romero’s guidance on the theory and observations of swell-waves and his help in preparing Fig. 1.
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A more accurate drag law should include the influence of swell waves on CD for low wind speed (Sullivan et al. 2008).
Similarly, Harcourt (2013) proposes a local second-moment turbulence closure model based on Lagrangian-mean shear rather than Eulerian.
This result is based on LES solutions with an equilibrium wind-wave Stokes profiles whose amplitude is artificially reduced to increase La above its equilibrium value of 0.3. These solutions are not shown here explicitly, but both Harcourt and D’Asaro (2008) and Grant and Belcher (2009) show results for this larger La regime.
In LES cases that go beyond the largest Ds value in case set Ds, the further increases in Ds lead to little change in the turbulent intensity and fluxes. However, the anti-Stokes component in
Van Roekel et al. (2012, their Fig. 8) shows a monotonic decrease in
To be specific we have in mind a calculation for given 1D profiles of
An alternative statistical measure of Langmuir circulation orientation is the direction determined by a peak in the distribution function for tan−1(ωy/ωx), where ω is the vorticity vector (see, e.g., Van Roekel et al. 2012). This gives similar results to the correlation function method used here, but with somewhat greater estimation noise.
The elliptical fit parameters are only weakly dependent on the Cw value as long as εLC is not too close to 1.
The nonequilibrium misalignment cases examined in Van Roekel et al. (2012) all have nonnegative wave rotation angles relative to the wind θ equal to or greater than zero.
In present implementations of the KPP scheme in circulation models, there are two alternative formulations for the critical Richardson number condition that determines the boundary layer depth h. One formulation is expressed as a ratio of the bulk differences across the boundary layer of buoyancy change and velocity change squared; in this representation