The Mantis Network II: Examining the 3D high-resolution observable properties of the UHJs WASP-121b and WASP-189b through GCM modelling

TL;DR

This study uses 3D GCM modeling with UV opacities to analyze the atmospheres of UHJs WASP-121b and WASP-189b, revealing UV-driven thermal inversions and distinct upper atmospheric dynamics.

Contribution

It introduces high-resolution 3D GCM models including UV absorption effects, providing new insights into the thermal and dynamical structure of UHJ atmospheres.

Findings

UV opacities cause sharp temperature inversions.

High-res observations probe upper atmospheric layers.

Models align with previous 1D T-p structure trends.

Abstract

The atmospheres of ultra hot Jupiters (UHJs) are prime targets for the detection of molecules and atoms at both low and high spectral resolution. We study the atmospheres of the UHJs WASP-121b and WASP-189b by performing 3D general circulation models (GCMs) of these planets using high temperature correlated-k opacity schemes with ultra-violet (UV) absorbing species included. The GCM results are then post-processed at low and high spectral resolutions and compared to available data. The high resolution results are cross-correlated with molecular and atomic templates to produce mock molecular detections. Our GCM models produce similar temperature-pressure (T-p) structure trends to previous 1D radiative-convective equilibrium models of UHJs. Furthermore, the inclusion of UV opacities greatly shapes the thermal and dynamical properties of the high-altitude, low-pressure regions of the UHJ atmospheres, with sharp T-p inversions due to the absorption of UV light. This suggests that optical wavelength, high-resolution observations probe a dynamically distinct upper atmospheric region, rather than the deeper jet forming layers.