Question about Smagorinsky mixing coefficients

[dylanrs617]

Hi All,

I'm doing some experiments with Smagorinsky viscosity/diffusion applied biharmonically along geopotential surfaces to explore its impacts on numerical mixing. In hmixing.F, I see that Bsmag is controlled by PecletCoef, which is equal to 1/12. Where does the 1/12 come from? It's unclear to me from Smagorinsky (1963) and Griffies and Hallberg (2000).

Thanks,
Dylan