Formation and dynamics of water clouds on K2-18 b

Benjamin Charnay; Doriann Blain; Bruno Bézard; Jérémy Leconte; Martin Turbet

doi:https://doi.org/10.5194/epsc2020-889

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EPSC Abstracts

Vol.14, EPSC2020-889, 2020

https://doi.org/10.5194/epsc2020-889

Europlanet Science Congress 2020

© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Formation and dynamics of water clouds on K2-18 b

Benjamin Charnay¹, Doriann Blain¹, Bruno Bézard¹, Jérémy Leconte², and Martin Turbet³

Benjamin Charnay et al.

¹CNRS Observatoire de Paris, LESIA, Meudon, France (benjamin.charnay@obspm.fr)
²Laboratoire d'Astrophysique de Bordeaux, Bordeaux, France
³Observatoire astronomique de l ́Université de Geneve, Switzerland

K2-18 b is a temperate sub-Neptune orbiting in the habitable zone of a nearby M star. Recent analysis of HST transit observations revealed the presence of water vapour and potentially water clouds. K2-18b is a unique opportunity to characterize the physics, chemistry and dynamics of temperate low-mass exoplanets.

We present here the results of 3D atmospheric modelling of K2-18b including water clouds with radiative effects. We investigate the effects of atmospheric metallicity (from 1xsolar to 1000xsolar), the concentration of cloud condensation nuclei, microphysics and rotation rate on the distribution of water clouds. We also analyze the impact of clouds and their spatial/time variability on transmission and emission spectra. Finally, we show how future observations with JWST, ELTs and ARIEL would constrain the atmospheric composition and clouds of this planet.

How to cite: Charnay, B., Blain, D., Bézard, B., Leconte, J., and Turbet, M.: Formation and dynamics of water clouds on K2-18 b, Europlanet Science Congress 2020, online, 21 September–9 Oct 2020, EPSC2020-889, https://doi.org/10.5194/epsc2020-889, 2020