Bridging the Atmospheric Circulations of Hot and Warm Giant Exoplanets

TL;DR

This study uses high-resolution simulations to compare atmospheric circulation patterns of hot and warm tidally locked giant exoplanets, revealing similar qualitative behaviors despite temperature differences, driven by dynamical regimes.

Contribution

It demonstrates that hot and warm giant exoplanets in similar dynamical regimes exhibit comparable circulation patterns, highlighting the role of Rossby and Froude numbers in atmospheric dynamics.

Findings

Similar circulation patterns in hot and warm exoplanets despite temperature differences

Quantitative differences linked to Rossby deformation scales

Presence of turbulent equatorial flows and Rossby waves

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-11b and WASP-39b, 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 gives rise to quasi-zonal flows in the extra-tropics (i.e., near ~20 degrees). Quantitative differences between the KELT-11b and WASP-39b atmospheres reflect their different Rossby deformation scales, which influence the horizontal length scale of wave--vortex interactions and the overall structure of the circulation.