Jupiter’s Red Spot

The Great Red Spot, the largest of Jupiter’s long lived, approximately two dimensional, coherent vortices, measures approximately 26, 000 × 13, 000 km in the horizontal direction and is assumed to be roughly 20-40 km deep. Previous studies, including laboratory experiments and numerical simulations, suggest that many of the important characteristics of Jovian vortices can be explained through quasi-geostrophic theory. Based on work by Phillip Marucs, a simple two layer model of the Jovian atmosphere is developed in which vortices lie in a thin layer of the atmosphere above a much deeper, time independent flow. The lower layer only influences the upper layer by changing its vertical depth. The fluid in the upper layer is assumed to be homogeneous and incompressible. Starting with the full momentum equation, standard scaling arguments are used to motivate the quasi-geostrophic and hydrostatic equations. From the approximate horizontal momentum equations, the conservation of potential vorticity is derived and used in a model for Jovian vortices. The resulting system is solved numerically using a combination of Galerkin and finite difference methods. Data from several simulations is presented and compared with previous results.