Exotic meteorology in the atmospheres and interiors of gas planets

The profusion of planets observed in the galaxy to have hydrogen-dominated envelopes entreats a deeper understanding of how convection operates on such bodies.  In this presentation, we will focus on two important aspects of such planets: convective inhibition, and abyssal rain.  Convective inhibition refers to the process by which super-adiabatic temperature gradients can be stabilized against convection in hydrogen atmospheres in the presence of volatile condensates like water.  We discuss its applications to the thermal evolution of Uranus and Neptune, and to interior models of sub-Neptune/super-Earths.  Next, we ponder what happens to rain in stormy atmospheres when there is no surface to stop it from falling.  Through theoretical and computational models, we argue that rain should penetrate to great depths without efficiently mixing with its surroundings, offering a possible explanation for Juno measurements of Jupiter's ammonia distribution, and a caution to interpretation of measurements of exoplanet atmospheric compositions.