HR: 09:15h
AN: A51E-06    [Abstracts]
TI: Dynamic LES Modeling of Observed Diurnal Cycles
AU: * Basu, S
EM: sukanta.basu@ttu.edu
AF: Texas Tech University, Atmospheric Science Group, Department of Geosciences, MS 42101, Lubbock, TX 79409, United States
AU: Vinuesa, J
EM: jeff.vinuesa@jrc.it
AF: European Commission - DG Joint Research Centre, Institute for Environment and Sustainability, TP441, Via E. Fermi, Ispra, 1 21020, Italy
AB: The diurnally varying atmospheric boundary layers observed during the Wangara and CASES-99 field campaigns are simulated using the newly proposed locally-averaged scale-dependent dynamic subgrid-scale (SGS) model. This tuning-free SGS model enables one to dynamically compute the Smagorinsky coefficient and the subgrid- scale Prandtl number based on the local dynamics of the resolved velocity and temperature fields. We show that this SGS model-based large-eddy simulation (LES) has the ability to reproduce with great accuracy the characteristics of observed atmospheric boundary layers even with relatively coarse resolutions. In particular, the development, magnitude, and location of an observed nocturnal low-level jet are very well depicted. Some well- established empirical formulations (e.g., mixed layer and local scaling) are recovered with good accuracy by this LES-SGS parameterization. In this presentation, we also delineate the potential of this new-generation dynamic LES-SGS modeling approach to revise and improve existing numerical weather prediction boundary layer parameterizations.
DE: 3307 Boundary layer processes
DE: 3322 Land/atmosphere interactions (1218, 1631, 1843)
DE: 3355 Regional modeling
DE: 3379 Turbulence (4490)
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly