Numerical simulation of the atmosphere has grown tremendously over the last few decades. Nevertheless, simulation problems remain, affecting the accuracy and usefulness of the simulations. Simulation errors have recently been documented in which the differences between the real atmosphere and the simulation were found entirely within the ABL. Since the ABL is not explicitly modeled in most models, we need to look closely at the ABL parameterizations as a likely source of these errors.
We will present output from the MM5 mesoscale model concentrating on the differences made by using the five different boundary layer parameterization schemes. Most of the cases were run at the University of Washington using a doubly nested, 12km grid centered on the Pacific Northwest. The development of the differences in the boundary layer structure and the extent of these differences will be shown.