Large-eddy simulation study of log laws in a neutral Ekman boundary layer

These simulations produce a constant momentum flux layer and a log-law layer above the surface characterized by a logarithmic increase of wind speed with height. The von Karman constant derived from the mean wind profile is around 0.4 over a wide range of control parameters.

The depths of the simulated boundary layer, constant-flux layer, and surface log-law layer tend to increase with the wind speed and decrease with an increasing Coriolis parameter. Immediately above the surface log-law layer, a second log-law layer has been identified from these simulations. The depth of this upper log-law layer is comparable to its counterpart in the surface layer, and the wind speed can be scaled as u(*)(u(*)/fh)(3/4), as opposed to just u(*) in the surface log-law layer, implying that in addition to surface processes, the upper log-law layer is also influenced by Earth's rotation and large-scale conditions.