Dr Jean Reinaud (St-Andrews University): Thomson’s vortices in a three-dimensional quasi-geostrophic flow: A (small) step further to understand pattern formation on Jupiter’s poles
Pictures taken by the Juno spacecraft have revealed the presence of quasi-regular vortex arrays over the poles of Jupiter. To persist in time, such vortex arrays should form a stable relative equilibrium. The vortices are influenced by the background rotation of giant gas planet, and the density stratification of its weather layer. These two features can be accurately captured by an asymptotic dynamical model: the quasi-geostrophic model. I will examine arrays of both quasi-geostrophic point vortices and finite volume vortices in mutual equilibrium in a three-dimensional, continuously stratified fluid, and I will address their stability properties. I will also propose a possible scenario for the formation of such vortex arrays through the destabilisation of a torus of potential vorticity. This latter part is a work in collaboration with Prof David Dritschel.