GCM Simulations of Unstable Climates in the Habitable Zone


Snowball Earth

It has recently been proposed that Earth-like planets in the outer regions of the habitable zone experience unstable climates, repeatedly cycling between glaciated and deglaciated climatic states (Menou 2015).

While this result has been confirmed and also extended to explain early Mars climate records (Haqq-Misra et al. 2016; Batalha et al. 2016), all existing work relies on highly idealized zero-dimensional climate models. Here, we confirm that the phenomenology of climate cycles remains in 3D Earth climate models with considerably more degrees of freedom.

To circumvent the computational barrier of integrating climate on Gyr timescales, we design a hybrid 0D-3D integrator which uses a general circulation model (GCM) as a short relaxation step along a long evolutionary climate sequence. We find that GCM climate cycles are qualitatively consistent with reported zero-dimensional results. This establishes on a firmer ground the notion that outer habitable zone planets may be preferentially found in transiently glaciated states.

Adiv Paradise, Kristen Menou
(Submitted on 14 Apr 2017)

Comments: 15 pages, 5 figures, submitted to ApJ
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1704.04535 [astro-ph.EP] (or arXiv:1704.04535v1 [astro-ph.EP] for this version)
Submission history
From: Adiv Paradise
[v1] Fri, 14 Apr 2017 20:36:42 GMT (1846kb,D)


Please follow Astrobiology on Twitter.

  • submit to reddit