Modeled Temperature-Dependent Clouds with Radiative Feedback in Hot Jupiter Atmospheres

TL;DR

This study uses a general circulation model with new cloud physics to show how radiative feedback influences cloud distribution and temperature in hot Jupiter atmospheres, highlighting the importance of active cloud modeling.

Contribution

It introduces a simple parameterization of clouds with radiative feedback in GCMs and compares active versus post-processed cloud treatments in hot Jupiter simulations.

Findings

Active cloud modeling reduces equatorial cloud cover and increases polar clouds.

Active feedback alters phase curves, showing stronger day-night contrasts.

Post-processing underestimates cloud radiative effects, leading to inaccuracies.

Abstract

Using a general circulation model with newly implemented cloud modeling, we investigate how radiative feedback can self-consistently shape condensate cloud distributions, temperatures, and fluxes in a hot Jupiter atmosphere. We apply a physically motivated but simple parameterization of condensate clouds in which the temperature determines the cloud distribution, and we evaluate how different assumptions of vertical mixing and aerosol scattering parameters affect predictions. We compare results from cases in which the aerosols are simply included in the last step of the simulation (i.e. post-processed) to cases in which clouds and their radiative feedback are actively included throughout the duration of the simulation. When clouds and radiative feedback were actively included, cloud cover decreased at equatorial regions and increased towards the poles relative to the post-processed solutions. The resulting phase curves also differed between the two approaches; the post-processed cloud simulations predicted weaker day-night contrasts in emission and greater eastward shifts in the maximum emission compared to the active cloud modeling. This illustrates the importance of cloud radiative feedback and shows that post-processing will provide inaccurate solutions when clouds are thick enough to provide significant scattering.