The 3D thermal, dynamical and chemical structure of the atmosphere of HD 189733b: implications of wind-driven chemistry for the emission phase curve

TL;DR

This study uses 3D atmospheric simulations to explore how wind-driven chemistry affects the thermal, dynamical, and chemical structure of HD 189733b, revealing significant impacts on temperature, wind, and emission phase curves.

Contribution

It introduces a coupled 3D model that includes wind-driven chemical advection, providing new insights into atmospheric structure and emission characteristics of HD 189733b.

Findings

Wind-driven chemistry significantly alters temperature and wind velocities (~10%).

Chemical advection impacts the three-dimensional structure of the contribution function.

Wind-driven chemistry notably affects the thermal emission in the 3.6 μm Spitzer/IRAC channel.

Abstract

In this paper we present three-dimensional atmospheric simulations of the hot Jupiter HD~189733b under two different scenarios: local chemical equilibrium and including advection of the chemistry by the resolved wind. Our model consistently couples the treatment of dynamics, radiative transfer and chemistry, completing the feedback cycle between these three important processes. The effect of wind--driven advection on the chemical composition is qualitatively similar to our previous results for the warmer atmosphere of HD~209458b, found using the same model. However, we find more significant alterations to both the thermal and dynamical structure for the cooler atmosphere of HD~189733b, with changes in both the temperature and wind velocities reaching $\sim10\%$. We also present the contribution function, diagnosed from our simulations, and show that wind--driven chemistry has a significant impact on its three--dimensional structure, particularly for regions where methane is an important absorber. Finally, we present emission phase curves from our simulations and show the significant effect of wind--driven chemistry on the thermal emission, particularly within the 3.6 \textmu m Spitzer/IRAC channel.