Why do some convection models predict high Mach number convection in Jupiter-like planets?

Deep in the optically thick region of a gas giant planet’s atmosphere, collisionally-induced absorption dominates the opacity, and produces an opacity which is proportional to the pressure. The temperature and pressure stratification of these regions is nearly polytropic. The natural polytrope for an opacity which scales with pressure is strongly superadiabatic. We present multi-dimensional simulations of boundary-driven convection in these polytropic states, which are heated from below and cooled from above, and find high Mach number, shock-producing convection. However, convection in the deep atmosphere of a planet like Jupiter is typically assumed to be low Mach number. We additionally study a comparable but more realistic model of convection where the system is cooled from above and heated internally. We find that the internally-heated convection model produces weaker convective upflows and lower-Mach number flows. As the dynamics each model produces are distinct, it is important to choose the appropriate model for the system being simulated. We discuss where it is appropriate to use each model.