78 research outputs found
A systematic study of \ce{CO2} planetary atmospheres and their link to the stellar environment
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 \ce{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.Comment: 12 pages, 9 figures, accepted for publication in MNRA
Modeling Atmospheric Lines By the Exoplanet Community (MALBEC) version 1.0: A CUISINES radiative transfer intercomparison project
Radiative transfer (RT) models are critical in the interpretation of
exoplanetary spectra, in simulating exoplanet climates and when designing the
specifications of future flagship observatories. However, most models differ in
methodologies and input data, which can lead to significantly different
spectra. In this paper, we present the experimental protocol of the MALBEC
(Modeling Atmospheric Lines By the Exoplanet Community) project. MALBEC is an
exoplanet model intercomparison project (exoMIP) that belongs to the CUISINES
(Climates Using Interactive Suites of Intercomparisons Nested for Exoplanet
Studies) framework which aims to provide the exoplanet community with a large
and diverse set of comparison and validation of models. The proposed protocol
tests include a large set of initial participating RT models, a broad range of
atmospheres (from Hot Jupiters to temperate terrestrials) and several
observation geometries, which would allow us to quantify and compare the
differences between different RT models used by the exoplanetary community. Two
types of tests are proposed: transit spectroscopy and direct imaging modeling,
with results from the proposed tests to be published in dedicated follow-up
papers. To encourage the community to join this comparison effort and as an
example, we present simulation results for one specific transit case (GJ-1214
b), in which we find notable differences in how the various codes handle the
discretization of the atmospheres (e.g., sub-layering), the treatment of
molecular opacities (e.g., correlated-k, line-by-line) and the default
spectroscopic repositories generally used by each model (e.g., HITRAN, HITEMP,
ExoMol)
Large interferometer for exoplanets (LIFE). I. Improved exoplanet detection yield estimates for a large mid-infrared space-interferometer mission
Stars and planetary system
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