THURSDAY, July 7, 2005
Time: 11:00 - 12:00
ECSB 2120

Title: Eulerian and Lagrangian Statistics in Rotating Turbulence With and Without Stable Stratification

Prof. Claude Cambon
Atmospheric and Aeronautical Turbulence
Ecole Centrale de Lyon, France

Turbulence subject to system rotation is investigated with and without stable density stratification, using high resolution (512^3) DNS and statistical QNM (Quasi-Normal Markovian) theory/modelling. Emphasis is placed on (statistically) homogeneous three-dimensional turbulence --- with no shallow water approach --- with detailed 3D anisotropic structure. The external parameters are the Coriolis factor f and the Brumt-Waisala frequency N. Depending on the ratio N/f, different oriented structures, pancake or cigar-type, dynamically emerge from the initial, isotropic and unstructured, state. Angle-dependent energy spectra are shown to quantize this anisotropic structuring. Although the flows studied here are idealized with respect to actual geophysical flows in the atmosphere and in the ocean, important issues on two-dimensionalization and on two-componentalization (layering) can be addressed and revisited.