The large scale heights and dayside atmospheric temperatures make ultra hot Jupiters (UHJs) a favourite target for low and high resolution spectral observations. We investigate the 3D atmospheric properties of the UHJs WASP-121b and WASP-189b using the Exo-FMS GCM model (Lee et al. 2021, MNRAS, 506). The radiative-transfer (RT) scheme for the GCMs was upgraded to include several near-UV (NUV) absorbing species such as Fe, Fe+ and SiO, following the 1D radiative-convective equilibrium modelling results by Lothringer et al. (2020, ApJL, 1). We then run the GCM models for both planets for 3050 days, taking the last 50 day average as the final result. The GCM outputs are then post-processed for transmission and emission spectra using the 3D Monte Carlo RT model gCMCRT (Lee et al. 2022, arXiv:2110.15640) at low-resolution and compared to available observational data. We then process the GCM models at high spectral resolution including Doppler shifting of lines due to winds and planetary rotation for the HARPS instrument for WASP-189b following Prinoth et al. (2022, NatAst, in press). WASP-121b is then processed at high resolution at optical wavelengths as a full phase curve.

SNSF funding through Ambizione Fellowship project: PZ00P2_193448