Nonlinear Processes in Geophysics www.nonlin-processes-geophys.net 1023-5809 1607-7946 12 6 2005 10.5194/npg-12-947-2005 http://www.nonlin-processes-geophys.net/12/947/2005/ http://www.nonlin-processes-geophys.net/12/947/2005/npg-12-947-2005.html http://www.nonlin-processes-geophys.net/12/947/2005/npg-12-947-2005.pdf 947 953 2005-11-04 Rossby-wave turbulence in a rapidly rotating sphere N. Schaeffer P. Cardin philippe.cardin@ujf-grenoble.fr LGIT, Observatoire de Grenoble, Universit\'e Joseph Fourier, Grenoble, France 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. <br /> The equilibrium regime is strongly anisotropic and inhomogeneous but exhibits a steep <i>m^-5</i> 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.