The adaptation of the atmospheric boundary layer to a change in surface roughness

The adaptation of the atmospheric boundary layer to a change in the underly ing surface roughness is an interesting problem and hence much research, th eoretical, experimental, and numerical, has been undertaken. Within the atm ospheric boundary layer an accurate numerical model for the turbulent prope rties of the atmospheric boundary layer needs to be implemented if physical ly realistic results are to be obtained. Here, the adaptation of the atmosp heric boundary layer to a change in surface roughness is investigated using a first-order turbulence closure model, a one-and-a-half-order turbulence closure model and a second-order turbulence closure model. Perturbations to the geostrophic wind and the pressure gradients are included and it is sho wn that the second-order turbulence closure model, namely the standard k - epsilon model, is inferior to a lower-order closure model if a modification to limit the turbulent eddy size within the atmospheric boundary layer is not included within the model.