3D Climate modelling of TRAPPIST-1 c with a Venus-like atmosphere: large-scale circulation and observational prospects
- 1Instituto de Astrofísica e Ciências do Espaço (IA), OAL, Lisboa, Portugal (dquirino@oal.ul.pt)
- 2Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
- 3Instituto de Astrofísica de Andalucía (IAA/CSIC), Granada, Spain
- 4McGill University, Montréal, Canada
- 5Space Science Institute, Boulder, CO, USA
- 6Laboratoire de Météorologie Dynamique/IPSL, CNRS, Sorbonne Université, Ecole Normale Supérieure, PSL Research University, Ecole Polytechnique, 75005 Paris, France
- 7Observatoire astronomique de l'Université de Genève, 51 chemin des Maillettes, 1290 Sauverny, Switzerland
- 8NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
- 9American University, Washington DC, USA
In recent years, several Earth-sized exoplanets have been detected in short-period orbits of a few Earth days, around low-mass stars [1]. Despite their small size compared to gas giants, their close-in orbits combined with the small radius of the host star compared to our Sun’s make these worlds the best targets for atmospheric characterisation among rocky exoplanets. These worlds have stellar irradiation levels that can be several times that of the Earth, suggesting that a Venus-like climate is more likely [2]. Thus, the atmosphere of our neighbouring planet Venus presents a relevant case to address observational prospects.
The recent launch of the James Webb Space Telescope will advance the atmosphere and climate characterisation of nearby rocky exoplanets, with the support of upcoming ground-based observatories and space telescopes, such as the ESA/Ariel mission, scheduled for launch in 2029. The interpretation of the observables produced by these missions: reflectance, thermal emission and transmission spectra will need support from modelling studies of exoplanetary atmospheres. In particular, 3D Global Climate Models (GCMs) are critical for interpreting the observable signal’s modulations, as they provide synthetic top-of-the-atmosphere fluxes that can be disk-integrated as a function of the orbital phase. The spatial and temporal variability of these fluxes reflect the atmospheric variability of the simulated temperature and wind fields and provide insight over the large-scale circulation.
In this work, we used the Generic-GCM, developed at the Laboratoire de Météorologie Dynamique for exoplanet and paleoclimate studies [3, 4, 5], which includes a 3D dynamical core, common to all terrestrial planets, a planet-specific physical core, and an up-to-date generalised radiative transfer routine for variable atmospheric compositions.
We present the results of modelling highly irradiated rocky exoplanets orbiting an M-dwarf star, using a Venus-like atmosphere as a possible framework for the atmospheric conditions of TRAPPIST-1 c. We assumed synchronous rotation, zero eccentricity and obliquity, and a Venus-like atmosphere with 92-bar surface pressure and a radiatively active Venus-type global cloud cover. The results indicate an eastward shift of the peak thermal emission away from the sub-stellar point, suggesting an advection of warm air masses caused by a superrotation equatorial jet.
References:
[1] Gillon et al. 2017. Nature. 542.
[2] Kane et al. 2018. ApJ. 869.
[3] Forget & Leconte, 2014. Phil. Trans R. Soc. A372.
[4] Turbet et al. 2016. A&A. 596. A112.
[5] Wordsworth et al. 2011. ApJL. 733. L48.
Acknowledgements:
This work is supported by Fundação para a Ciência e a Tecnologia (FCT) through the research grants UIDB/04434/2020, UIDP/04434/2020, P-TUGA PTDC/FIS-AST/29942/2017.
How to cite: Quirino, D., Gilli, G., Navarro, T., Turbet, M., Fauchez, T., and Machado, P.: 3D Climate modelling of TRAPPIST-1 c with a Venus-like atmosphere: large-scale circulation and observational prospects, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8185, https://doi.org/10.5194/egusphere-egu22-8185, 2022.
