Extended Abstract (332K)15.6
Local scaling of turbulence in the stable internal boundary layer around a coastal headland
Stefan Söderberg, Stockholm University, Stockholm, Sweden; and I. M. Brooks and M. Tjernström
We present aircraft observations and numerical modeling of the response of the 3-dimensional tur-bu-lence structure of the stable atmospheric boundary layer to the interaction of the mesoscale flow and coastal topography. The measurements were made by the NCAR C-130 off the coast of California, around Cape Mendocino, during the Coastal Waves 96 field program and the subsequent modeling is based on the observed meteorology.
As the flow rounds the Cape, it diverges and accelerates to form an expansion fan. Northwesterly winds bring the marine air-mass over cool, upwelling coastal waters, resulting in the formation of a stable internal boundary layer (IBL). Turbulence is largely confined to the IBL, and is shear driven. Although this boundary layer is far from the ideal horizontally homogeneous and stationary conditions usually required in scaling, tur-bu-len-ce within this IBL can be scaled using local similarity scaling. Bulk estimates of the surface fluxes derived from near-surface measurements of mean quantities, however, differ significantly from direct eddy-correlation measurements.
This presentation is a companion presentation to the poster-presentation "Taking a closer look at the turbulence in a higher-order closure mesoscale model", where a more detailed discussion of the modeling effort will be given.
Session 15, Boundary Layers over Heterogeneous Surfaces
Friday, 19 July 2002, 8:30 AM-12:15 PM
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