Bridging the Atmospheric Circulations of Hot and Warm Giant Exoplanets

Abstract We perform high-resolution atmospheric flow simulations of hot and warm giant exoplanets that are tidally locked. The modeled atmospheres are representative of those on KELT-11 b and WASP-39 b, which possess markedly different equilibrium temperatures but reside in a similar dynamical regime. In this regime, their key dynamical numbers (e.g., Rossby and Froude numbers) are comparable. Despite their temperature difference, both planets exhibit qualitatively similar atmospheric circulation patterns, which are characterized by turbulent equatorial flows, anticyclonic polar vortices, and large-scale Rossby waves that give rise to quasi-zonal flows in the extratropics (i.e., near ±20 ∘ ). Quantitative differences between the KELT-11 b and WASP-39 b atmospheres are consistent with their different Rossby deformation scales, which influence the horizontal length scale of wave–vortex interactions and the overall structure of the circulation.