Large-Eddy Simulations of the Stable Boundary Layer Using the Standard Kolmogorov Theory: Range of Applicability

Large-eddy simulations (LES) of the Stable Atmospheric Boundary Layer (SBL) are difficult because the turbulence is not isotropic for strong stratification and the Kolmogorov theory might be no longer valid. This fact compells us to work on modifications to the subgrid turbulence schemes, although there is not any widely accepted theory on anisotropic turbulence. In this work, a LES model is used to see what range of stable stratification can still be simulated with a subgrid turbulence scheme using the Kolmogorov theory for the dissipation. Twenty simulations of increasing stability have been performed using a horizontal resolution of 5 m. The model is able to simulate weakly and moderately stable conditions and experiences runaway cooling for strong stability. The goodness of the successful simulations is inspected through comparison to observations from the experimental campaigns SABLES-98 and CASES-99. Other supplementary tests have been performed on the resolution and the surface boundary condition.