Laboratory simulation of Jupiter's Great Red Spot

Isolated large stable vortices have long been observed in the jovian atmosphere and more recently on Saturn. The existence of such stable vortices in strongly turbulent planetary atmospheres is a challenging problem in fluid mechanics. In a numerical simulation Marcus1 found that a single stable vortex developed for a wide variety of conditions in a turbulent shear flow in a rotating annulus. To test this we conducted an experiment on a rotating annulus filled with fluid pumped in the radial direction. The annulus rotates rigidly (there is no differential rotation), but the action of the Coriolis force on the radially pumped fluid produces a counter-rotating jet. Coherent vortices spontaneously form in this turbulent jet, and for a wide range of rotation and pumping rates the flow evolves until only one large vortex remains.