Coupled day–night models of exoplanetary atmospheres

Abstract

ABSTRACT We provide a new framework to model the day side and night side atmospheres of irradiated exoplanets using 1D radiative transfer by incorporating a self-consistent heat flux carried by circulation currents (winds) between the two sides. The advantages of our model are its physical motivation and computational efficiency, which allows for an exploration of a wide range of atmospheric parameters. We use this forward model to explore the day and night side atmosphere of WASP-76 b, an ultrahot Jupiter which shows evidence for a thermal inversion and Fe condensation, and WASP-43 b, comparing our model against high precision phase curves and general circulation models. We are able to closely match the observations as well as prior theoretical predictions for both of these planets with our model. We also model a range of hot Jupiters with equilibrium temperatures between 1000 and 3000 K and reproduce the observed trend that the day–night temperature contrast increases with equilibrium temperature up to ∼2500 K beyond which the dissociation of H2 becomes significant and the relative temperature difference declines.