Simulated Phase-dependent Spectra of Terrestrial Aquaplanets in M Dwarf Systems

Orbital phase-dependent variations in thermal emission and reflected stellar energy spectra can provide meaningful constraints on the climate states of terrestrial extrasolar planets orbiting M dwarf stars.

Spatial distributions of water vapor, clouds, and surface ice are controlled by climate. In turn, water, in each of its thermodynamic phases, imposes significant modulations to thermal and reflected planetary spectra. Here we explore these characteristic spectral signals, based on 3D climate simulations of Earth-sized aquaplanets orbiting M dwarf stars near the habitable zone.

By using 3D models, we can self-consistently predict surface temperatures and the location of water vapor, clouds, and surface ice in the climate system. Habitable zone planets in M dwarf systems are expected to be in synchronous rotation with their host star and thus present distinct differences in emitted and reflected energy fluxes depending on the observed hemisphere. Here we illustrate that icy, temperate, and incipient runaway greenhouse climate states exhibit phase-dependent spectral signals that enable their characterization.

E.T. Wolf, R.K. Kopparapu, J. Haqq-Misra
(Submitted on 6 Jun 2019)

Comments: 54 pages, 12 figures, please grab the published article for your reading pleasure
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Journal reference: THE Astrophysical Journal, 877:35 (18pp), 2019 May 20
DOI: 10.3847/1538-4357/ab184a
Cite as: arXiv:1906.02697 [astro-ph.EP] (or arXiv:1906.02697v1 [astro-ph.EP] for this version)
Submission history
From: Eric Wolf
[v1] Thu, 6 Jun 2019 16:50:20 UTC (7,889 KB)
https://arxiv.org/abs/1906.02697
Astrobiology