Japan Geoscience Union Meeting 2021

Presentation information

[E] Poster

P (Space and Planetary Sciences ) » P-AE Astronomy & Extrasolar Bodies

[P-AE16] Exoplanets

Sun. Jun 6, 2021 5:15 PM - 6:30 PM Ch.06

convener:Masahiro Ikoma(Division of Science, National Astronomical Observatory of Japan), Norio Narita(The University of Tokyo), Yuka Fujii(National Astronomical Observatory of Japan)

5:15 PM - 6:30 PM

[PAE16-P06] Climate for exo-terrestrial planets with a 3D high resolution cloud resolved climate model: Effect of obliquity

*Takanori Kodama1, Daisuke Takasuka2, Takeshi Kuroda3, Tomoki Miyakawa4, Masaki Satoh4 (1.Komaba Institute for Science, The University of Tokyo, 2.Department of Information Science, Ochanomizu University, 3.Department of Geophysics, Tohoku University, 4.Atmosphere and Ocean Research Institute, The University of Tokyo)

Keywords:Exoplanets, Climates

A large number of exoplanets are detected and some of them are expected to be rocky planets with Earth-like bulk composition within the habitable zone. A characterization of atmospheres for exoplanets will start with new space telescopes. We are in a new era of exoplanetary science and will see more details for them. Recently, the climate for exoplanets in the habitable zone has been estimated with a three-dimensional climate mode. Thus, as observational information is accumulated, our understanding for the exoplanetary atmosphere gradually moves from the1D-averaged climate to the 3D climate which captures non-uniform distributions of components in the atmosphere.

In the atmospheric science for the Earth, the climate simulation incredibly developed and it can estimate cloud and water vapor distributions with explicit convection under the high-resolution horizontal mesh (~14km mesh). The distribution of clouds and water vapor should be significantly important in the exoplanetary atmosphere, especially tidally locked exoplanets. Thus, it will be good opportunity to apply their knowledge to the exoplanetary atmosphere. Do we really need such a high-resolution and cloud resolved GCM? We have not had the answer for this question yet.

Here, we introduce NICAM (Non-hydrostatic ICosahedral Atmospheric Model), known as a global cloud resolving model. This model can explicitly resolve cloud distributions and the vertical transport of water vapor. Additionally, we can simulate the climate with high resolution using FUGAKU. As a first step, we investigate the climate with different obliquity. We assumed aqua-planet configurations with 1 bar of air as a background atmosphere with 5 different obliquities (0º, 15º, 23.5º, 45º, and 60º). We ran three set of simulations: 1) low-resolution (~220km mesh as standard resolution of GCM for exoplanetary science) with parametrization for cloud formation, 2) low resolution + explicit cloud microphysics scheme, and 3) high-resolution (~14km mesh) + explicit cloud microphysics scheme. We will show the atmospheric circulation and meridional energy transport for an aqua planet with different obliquity and discuss water transport and the location of the ITCZ in this presentation.