2D Studies of Various Approximations Used for Modeling Convection in Giant Planets

Abstract

The effects of common approximations made when modeling convection in the interior of giant planets, like Jupiter, are examined using two-dimensional (2D) numerical calculations at high Rayleigh number (1010). Small scale flow structures along the upper boundary and large scales in the lower region are observed for an anelastic fluid spanning five density scale heights. A much more symmetric distribution in the scale of flow structures is observed for a Boussinesq fluid in which density stratification is neglected. The absence of magnetic fields results in higher fluid velocities and smaller scale flow structures. Neglecting the inertial terms produces narrower plumes and a fundamentally different fluid flow pattern for anelastic fluids. Although restricted to two dimensions, our results demonstrate that the spatial structure and time dependence of thermal convection are significantly influenced by density stratification, magnetic fields and inertia. These effects should not be ignored in three-dimensional (3D) convection models of giant planets.