Location
MC 5501
Speaker
Mike Waite, University of Waterloo
Title
Energy cascades and interactions across scales in atmospheric turbulence
Abstract
The turbulent fluid motions of the atmosphere involve interactions of eddies and waves across an incredible range of length scales, from planetary down to millimetre scales. These interactions involve eddies in geostrophic and hydrostatic balance at large scales, where the Coriolis effect and density stratification are strong, and isotropic three-dimensional turbulence at small scales, which is too fast to feel rotation and stratification. The mesoscale, from scales of kilometres to hundreds of kilometres, is between these extremes. Interactions between such a wide range of length scales present a challenge for both theory and numerical simulation. However, under certain conditions, order emerges from this myriad of interactions in the idea of a turbulent inertial range, which underlies classical theories of quasi-geostrophic (QG) turbulence and three-dimensional isotropic turbulence. These theories account for observed characteristics of atmospheric turbulence at very large and very small scales. However, turbulence in the mesoscale remains an open problem. Too small for QG turbulence and too large for isotropic turbulence, the mystery of mesoscale interactions has motivated research on stratified and rotating-stratified turbulence over the last few decades. This talk will give an overview of the history and fluid mechanics of the mesoscale cascade problem and discuss some recent progress in this area.
This event is part of the NSERC CREATE-funded Quantitative Climate Science summer school. More information about this initiative can be found at https://qcs-create2024.github.io/
