Quasi-geostrophic turbulence in a rotating homogeneous fluid

Quasi-two-dimensional turbulence is generated in a rotating cylinder by an homogeneous distribution of bottom sources and sinks which oscillate in time. Typical Reynolds numbers reach 2000 and inertial time-scales are about an order of magnitude smaller than the Ekman spin-up time. This allows the genuine inertial effects of the flow field such as the gross spectral evolution of the energy containing eddies to be emphasized. The case of no topography is first discussed. When the fluid is steadily forced, it is observed that the energy containing scale is significantly larger than the forcing scale. Theoretical arguments for that behavior are presented. In the decaying stage the red cascade is observed and rates of interaction are measured. The forcing is next applied over various large scale topographies modelling the geophysical beta effect. The polar beta plane geometry preserves the above spectral characteristics but at the same time introduces anisotropy into the flow pattern. A broad westwar...