Articles | Volume 12, issue 6
https://doi.org/10.5194/npg-12-947-2005
https://doi.org/10.5194/npg-12-947-2005
04 Nov 2005
04 Nov 2005

Rossby-wave turbulence in a rapidly rotating sphere

N. Schaeffer and P. Cardin

Abstract. We use a quasi-geostrophic numerical model to study the turbulence of rotating flows in a sphere, with realistic Ekman friction and bulk viscous dissipation. The forcing is caused by the destabilization of an axisymmetric Stewartson shear layer, generated by differential rotation, resulting in a forcing at rather large scales.
The equilibrium regime is strongly anisotropic and inhomogeneous but exhibits a steep m-5 spectrum in the azimuthal (periodic) direction, at scales smaller than the injection scale. This spectrum has been proposed by Rhines for a Rossby wave turbulence. For some parameter range, we observe a turbulent flow dominated by a large scale vortex located in the shear layer, reminding us of the Great Red Spot of Jupiter.