The 13th Symposium on Boundary Layers and Turbulence

5A.7
LARGE EDDY SIMULATION OF THE STABLY STRATIFIED PLANETARY BOUNDARY LAYER

E M. Saiki, Boulder, CO; and C. H. Moeng and P. P. Sullivan

While the convective atmospheric boundary layer has historically been studied in great detail, its nocturnal counterpart, the stable boundary layer (SBL), has been somewhat neglected. This is due mainly to the difficulties associated with examining the stable boundary layer observationally, theoretically, and/or computationally as stable boundary layer turbulence can range from being fully turbulent to highly intermittent depending upon the counteracting forces of buoyancy damping and shear production. The SBL is also complicated by additional characteristics such as sensitivity to sloping terrain, the presence of low level jets, and the development of gravity waves (which can be difficult to discern from the turbulence).

In this work we conduct a study of the nocturnal boundary layer using large-eddy simulation (LES). A nested grid method is applied to aid in resolving the smaller scale structures associated with stable flows. We simulate a strongly cooled, windy stable boundary layer in order to investigate the development of the low level jet and characterize the coherent structures present in the SBL. The capabilities of the current LES model are also evaluated in terms of its ability to successfully simulate the stable boundary layer

The 13th Symposium on Boundary Layers and Turbulence