Sensitivity of MM5-Simulated Boundary Layer Characteristics to Turbulence Parameterizations

Planetary Boundary Layer Turbulence

In previous chapters boundary layers were evident as thin layers across which thermal, dynamic, and material properties of a free interior flow make a transition to their boundary values and/or boundary fluxes. In those cases the thinness of the boundary layer was typically a statement of the smallness of the relevant diffusivity; e.g., the depth h of the laminar Ekman boundary layer scales as ...

Diurnal Cycles of Surface Winds and Temperatures as Simulated by Five Boundary Layer Parameterizations

Although most of the planetary boundary layer (PBL) parameterizations have demonstrated the capability to reproduce many meteorological phenomena in the lowest few kilometers, little attention has been paid to the prediction of the diurnal cycles of surface wind speed (VSFC) in relation to surface temperature (TSFC). In this study, the performance of five widely used PBL parameterizations in re...

Mm5 Wintertime Simulations of the Antarctic Boundary-layer Wind Forcing

The Sensitivity of the Numerical Simulation of the Southwest Monsoon Boundary Layer to the Choice of PBL Turbulence Parameterization in MM5

Summertime convection over Arizona typically begins in the early afternoon and continues into the night. This suggests that the evolution of the daytime planetary boundary layer is important to the development of Arizona convection. If numerical models are to provide useful guidance for forecasting convection during the monsoon, then the planetary boundary layer must be simulated as accurately ...

Dynamic response of boundary-layer turbulence to oscillatory shear

The temporal response of a well-developed turbulent boundary layer to the superposition of oscillatory shear has been measured experimentally, over a wide range of frequencies. The response is primarily a periodic organization in magnitude of components of the turbulent velocity field at the forcing frequency. Oscillatory production of turbulence arises predominantly as a modulation of the mean...