Ocean dynamics of outer solar system satellites

Abstract

Ocean worlds are prevalent in the solar system. Focusing on Enceladus, Titan, Europa, and Ganymede, I use rotating convection theory and numerical simulations to predict ocean currents and the potential for ice-ocean coupling. When the influence of rotation is relatively strong, the oceans have multiple zonal jets, axial convective motions, and most efficient heat transfer at high latitudes. This regime is most relevant to Enceladus and possibly to Titan, and may help explain their long-wavelength topography. For a more moderate rotational influence, fewer zonal jets form, Hadley-like circulation cells develop, and heat flux peaks near the equator. This regime is predicted for Europa, where it may help drive geologic activity via thermocompositional diapirism in the ice shell, and is possible for Titan. Weak rotational influence allows concentric zonal flows and overturning cells with no preferred orientation. Predictions for Ganymede's ocean span multiple regimes.