  In this study, we have identified certain fundamental limitations of a mixing
length parameterization used in a popular turbulent kinetic energy-based
subgrid-scale model. Replacing this parameterization with a more physically
realistic one significantly improves the overall quality of the large-eddy
simulations (LESs) of stable boundary layers. For the range of grid sizes
considered here (specifically, 1 m -- 12.5 m), the revision dramatically
reduces the grid-size sensitivity of the simulations. Most importantly, the
revised scheme allows us to reliably estimate the first- and second-order
statistics of a well-known LES intercomparison case, even with a coarse
grid-size of O(10 m).
