Ocean weather systems on icy moons, with application to Enceladus

We explore ocean circulation on a rotating icy moon driven by temperature
gradients imposed at its upper surface due to the suppression of the
freezing point of water with pressure, as might be induced by ice
thickness variations on Enceladus. Employing high-resolution simulations,
we find that eddies dominate the circulation and arise from baroclinic
instability, analogous to Earth’s weather systems. Multiple alternating
jets, resembling those of Jupiter’s atmosphere, are sustained by these
baroclinic eddies. We establish a theoretical model of the stratification
and circulation and present scaling laws for the magnitude of the
meridional heat transport. These are tested against numerical simulations.
Through the identification of key non-dimensional numbers, our simplified
model is applied to other icy moons. We conclude that baroclinic
instability is central to the general circulation of icy moons.