Modeling the effects of inhomogeneous aerosols on the hot Jupiter Kepler-7b's atmospheric circulation

TL;DR

This study uses 3D atmospheric modeling to explore how inhomogeneous aerosols influence the circulation and infrared emission of hot Jupiter Kepler-7b, revealing effects on hotspot location and phase curves.

Contribution

It introduces a simplified aerosol radiative transfer model with prescribed cloud distributions to simulate their impact on atmospheric dynamics and emission patterns.

Findings

A persistent equatorial jet advects aerosols from nightside to dayside.

Inhomogeneous aerosols cause eastward hotspot shifts beyond uniform models.

High clouds on the nightside can moderate hotspot displacement.

Abstract

Motivated by the observational evidence of inhomogeneous clouds in exoplanetary atmospheres, we investigate how proposed simple cloud distributions can affect atmospheric circulations and infrared emission. We simulated temperatures and winds for the hot Jupiter Kepler-7b using a three-dimensional atmospheric circulation model that included a simplified aerosol radiative transfer model. We prescribed fixed cloud distributions and scattering properties based on results previously inferred from Kepler-7b optical phase curves, including inhomogeneous aerosols centered along the western terminator and hypothetical cases in which aerosols additionally extended across much of the planet's night side. In all cases, a strong jet capable of advecting aerosols from a cooler nightside to dayside was found to persist, but only at the equator. Colder temperatures at mid- and polar-latitudes might permit aerosol to form on the dayside without the need for advection. By altering the deposition and redistribution of heat, aerosols along the western terminator produced an asymmetric heating that effectively shifts the hottest spot further east of the sub-stellar point than expected for a uniform distribution. The addition of opaque high clouds on the nightside can partly mitigate this enhanced shift by retaining heat that contributes to warming west of the hotspot. These expected differences in infrared phase curves could place constraints on proposed cloud distributions and their infrared opacities for brighter hot Jupiters.