14:00 〜 14:15
[PAE16-02] Global climate modeling of TRAPPIST-1e using MIROC for the model intercomparison
キーワード：太陽系外惑星、TRAPPIST-1、全球気候モデル
TRAPPIST-1 is an ultra-cool red dwarf star (M-dwarf) with the size of slightly larger than Jupiter, located at about 40 light-years away from our Sun. It has been found that at least seven rocky planets are orbiting the star within the semi-major axis of ~0.06 AU, receiving the comparable irradiation to the terrestrial planets of our Solar System. Especially, the planet TRAPPIST-1e, whose size is estimated to be ~92% of the Earth orbiting with the semi-major axis of ~0.028 AU and the period of ~6.1 days (Gillon et al., 2017), would be favorable to keep the warm temperature which the surface liquid water may stably exist, with the estimated irradiation of ~900 W m-2 (~66% of the Earth). Also, it is highly probable that TRAPPIST-1e has a synchronous (tidally-locked with the same periods of rotation and revolution) orbit against TRAPPIST-1, like Ganymede against Jupiter with the similar size and positional relationship.
If TRAPPIST-1e has a suitable atmosphere, it is expected that its environment would be habitable, i.e. suitable for the existence of life. Several studies using global climate models (GCMs) have investigated the possible habitable climate of TRAPPIST-1e (Wolf, 2017; Turbet et al., 2018; Fauchez et al., 2019), and a model intercomparison project with several kinds of conditions is also ongoing (Fauchez et al., 2019, 2020). On this context, we also started GCM simulations of TRAPPIST-1e using MIROC (Model for Interdisciplinary Research on Climate), which has been developed in the Atmosphere and Ocean Research Institute of The University of Tokyo, National Institute for Environmental Studies and Japan Agency for Marine-Earth Science and Technology, to join the intercomparison project for the robust validation and understanding of the habitability of the extrasolar planet.
We have performed the simulations of the possible climate of TRAPPIST-1e with four kinds of ideal conditions with the surface pressure of 1 bar along with Fauchez et al. (2020): 1) Ben1: a dry land planet with a N2 atmosphere including 400 ppm CO2, 2) Ben2: a dry land planet with a pure CO2 atmosphere, 3) Hab1: a slab ocean planet with a N2 atmosphere including 400 ppm CO2, and 4) Hab2: a slab ocean planet with a pure CO2 atmosphere, and got preliminary results for each condition. In the presentation, we are showing the results and discussions in comparisons with other GCMs joining the intercomparison project (LMDG: the Laboratoire de Météorologie Dynamique Generic model, ROCKE-3D: the Resolving Orbital and Climate Keys of Earth and Extraterrestrial Environments with Dynamics, ExoCAM: the Exoplanet Community Atmospheric Model, and the Met Office Unified Model) for the validations of MIROC to adapt to tidally-locked exoplanets and the habitability of TRAPPIST-1e.
If TRAPPIST-1e has a suitable atmosphere, it is expected that its environment would be habitable, i.e. suitable for the existence of life. Several studies using global climate models (GCMs) have investigated the possible habitable climate of TRAPPIST-1e (Wolf, 2017; Turbet et al., 2018; Fauchez et al., 2019), and a model intercomparison project with several kinds of conditions is also ongoing (Fauchez et al., 2019, 2020). On this context, we also started GCM simulations of TRAPPIST-1e using MIROC (Model for Interdisciplinary Research on Climate), which has been developed in the Atmosphere and Ocean Research Institute of The University of Tokyo, National Institute for Environmental Studies and Japan Agency for Marine-Earth Science and Technology, to join the intercomparison project for the robust validation and understanding of the habitability of the extrasolar planet.
We have performed the simulations of the possible climate of TRAPPIST-1e with four kinds of ideal conditions with the surface pressure of 1 bar along with Fauchez et al. (2020): 1) Ben1: a dry land planet with a N2 atmosphere including 400 ppm CO2, 2) Ben2: a dry land planet with a pure CO2 atmosphere, 3) Hab1: a slab ocean planet with a N2 atmosphere including 400 ppm CO2, and 4) Hab2: a slab ocean planet with a pure CO2 atmosphere, and got preliminary results for each condition. In the presentation, we are showing the results and discussions in comparisons with other GCMs joining the intercomparison project (LMDG: the Laboratoire de Météorologie Dynamique Generic model, ROCKE-3D: the Resolving Orbital and Climate Keys of Earth and Extraterrestrial Environments with Dynamics, ExoCAM: the Exoplanet Community Atmospheric Model, and the Met Office Unified Model) for the validations of MIROC to adapt to tidally-locked exoplanets and the habitability of TRAPPIST-1e.