No evidence for radius inflation in hot Jupiters from vertical advection of heat

TL;DR

This study uses an extensive 3D GCM simulation of an ultra hot Jupiter to investigate if vertical heat advection causes radius inflation, finding no evidence supporting this mechanism.

Contribution

It presents the longest 3D GCM simulation of an ultra hot Jupiter and introduces a method to accelerate temperature convergence in deep atmospheres.

Findings

Deep atmospheric layers are cold with no vertical heat transport.

Coupling between radiation and dynamics alone does not cause radius inflation.

The simulation reached a converged state after 86,000 days.

Abstract

Understanding the radiative-dynamical coupling between upper photosphere and deeper atmosphere is a key in understanding the abnormal large radii of hot Jupiters. One needs very long integration times of 3D general circulation models (GCMs) with self consistent radiative transfer to achieve a better understanding of the feedback process between dynamics and radiation. We here present the longest 3D non-gray GCM study (86000 d) of an ultra hot Jupiter (WASP-76 b) published to this date that reached a final converged state. Furthermore, we present a method that can be used to accelerate the path towards temperature convergence in the deep atmospheric layers. We find that the final converged temperature profile is cold in the deep atmospheric layers, lacking any sign of vertical transport of potential temperature by large scale atmospheric motions. We thus conclude that the coupling between radiation and dynamics alone is not sufficient to explain the abnormal large radii of inflated hot gas giants.