3D simulations of rotating moist convection using the Rainy-Bénard model

Moist convection is a key process in planetary atmospheres which drives storms and global scale circulation patterns. It differs from standard, dry convection through the presence of a buoyancy source from condensation. The 'Rainy-Bénard' model, first presented in Vallis et al. (2019), uses a simplified equation set to study the fundamental interaction between buoyancy driven flows and condensation. Here, we simulate 3D rotating 'Rainy-Bénard' convection in a regime where the system is marginally stable to dry convection, but unstable to moist convection. We ran a suite of simulations where varied Rayleigh number and Ekman number. We find that when the Ekman number is decreased at fixed Rayleigh number heat transport, as measured by the Nusselt number, is enhanced at intermediate rotation rates. As Ekman number is lowered beyond the intermediate rotation regime heat transport is reduced and ultimately convection is suppressed as expected. The increase in heat transport at intermediate rotation rates coincides with a drier domain and the transition to columnar dynamics. These results suggests that condensation-driven convection can be enhanced by rotation and that this effect can surpass rotational throttling under the right conditions.