A Statistical Equilibrium Model of Zonal Shears and Embedded Vortices in a Jovian Atmosphere

A prominent feature of two-dimensional and quasi-geostrophic turbulence is the formation of large-scale coherent structures among the smallscale fluctuations of the vorticity field. This separation-of-scales behavior is a consequence of the conservation of both energy and enstrophy by the dynamics, which results in a net flux of energy toward large scales and a net flux of enstrophy toward small scales. Many flows of this kind, whether free-decaying flows or weakly driven, can therefore be described approximately as coherent, deterministic structures on the large scales and disorganized, random motions on the small scales.