A Systematic Study of CO2 Planetary Atmospheres And Their Link To The Stellar Environment

Histogram (counts on the left ordinate axis) of modelled albedos for condensing (red dashed), and non-condensing (green dashed) models; the solid blue line describes the whole set of models. For each albedo bin, the stellar temperature (T?) distribution is shown as a reversed histogram whose counts are displayed in the right ordinate axis.

The Milky Way Galaxy is literally teeming with exoplanets; thousands of planets have been discovered, with thousands more planet candidates identified. Terrestrial-like planets are quite common around other stars, and are expected to be detected in large numbers in the future.

Such planets are the primary targets in the search for potentially habitable conditions outside the solar system. Determining the atmospheric composition of exoplanets is mandatory to understand their origin and evolution, as atmospheric processes play crucial roles in many aspects of planetary architecture. In this work we construct and exploit a 1D radiative transfer model based on the discrete-ordinates method in plane-parallel geometry. Radiative results are linked to a convective flux that redistributes energy at any altitude producing atmospheric profiles in radiative-convective equilibrium.

The model has been applied to a large number (6250) of closely dry synthetic CO2 atmospheres, and the resulting pressure and thermal profiles have been interpreted in terms of parameter variability. Although less accurate than 3D general circulation models, not properly accounting for e.g., clouds and atmospheric and ocean dynamics, 1D descriptions are computationally inexpensive and retain significant value by allowing multidimensional parameter sweeps with relative ease.

A. Petralia, E. Alei, G. Aresu, D.Locci, C.Cecchi-Pestellini, G.Micela, R.Claudi, A.Ciaravella

Comments: 12 pages, 9 figures, accepted for publication in MNRAS
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2006.16650 [astro-ph.EP] (or arXiv:2006.16650v1 [astro-ph.EP] for this version)
Submission history
From: Antonino Petralia
[v1] Tue, 30 Jun 2020 10:20:04 UTC (755 KB)

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