Extended Abstract (84K)P1.21
Large-eddy simulationof downslope flows
Eric D. Skyllingstad, Oregon State Univ., Corvallis, OR
A large-eddy simulation (LES) model is used to model the characteristics of katabatic flows over simple terrain. Experiments examine the effect of cross winds and slope angle on the flow evolution. Results from cross wind cases show that as the cross slope flow increases, the slope flow deepens faster and behaves more like a standard weakly stratified boundary layer. Comparisons are made between the LES results, observations, and output from a comparable mesoscale simulation using the Mellor-Yamada (M-Y) turbulence closure method. When compared with measurements, the LES is shows good qualitative agreement in the strength and location of the downslope jet and temperature profile. Results from the mesoscale model compare favorably with the LES output, although decreasing resolution causes a degradation in the slope flow structure. Comparsions between the M-Y turbulence statistics and the LES model are also presented.
Poster Session 1, PBL Processes and Modeling (with Coffee Break)
Monday, 17 June 2002, 2:45 PM-4:15 PM
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