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Methane release on Early Mars by atmospheric collapse and atmospheric reinflation

Kite, Edwin S. and Mischna, Michael A. and Gao, Peter and Yung, Yuk L. and Turbet, Martin (2020) Methane release on Early Mars by atmospheric collapse and atmospheric reinflation. Planetary and Space Science, 181 . Art. No. 104820. ISSN 0032-0633. doi:10.1016/j.pss.2019.104820.

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A candidate explanation for Early Mars rivers is atmospheric warming due to surface release of H₂ or CH₄ gas. However, it remains unknown how much gas could be released in a single event. We model the CH₄ release by one mechanism for rapid release of CH₄ from clathrate. By modeling how CH₄-clathrate release is affected by changes in Mars' obliquity and atmospheric composition, we find that a large fraction of total outgassing from CH₄ clathrate occurs following Mars' first prolonged atmospheric collapse. This atmosphere-collapse-initiated CH₄-release mechanism has three stages. (1) Rapid collapse of Early Mars’ carbon dioxide atmosphere initiates a slower shift of water ice from high ground to the poles. (2) Upon subsequent CO₂-atmosphere re-inflation and CO₂-greenhouse warming, low-latitude clathrate decomposes and releases methane gas. (3) Methane can then perturb atmospheric chemistry and surface temperature, until photochemical processes destroy the methane. Within our model, we find that under some circumstances a Titan-like haze layer would be expected to form, consistent with transient deposition of abundant complex abiotic organic matter on the Early Mars surface. We also find that this CH₄-release mechanism can warm Early Mars, but special circumstances are required in order to uncork 10¹⁷ kg of CH₄, the minimum needed for strong warming. Specifically, strong warming only occurs when the fraction of the hydrate stability zone that is initially occupied by clathrate exceeds 10%, and when Mars’ first prolonged atmospheric collapse occurs for atmospheric pressure >1 bar.

Item Type:Article
Related URLs:
URLURL TypeDescription
Kite, Edwin S.0000-0002-1426-1186
Mischna, Michael A.0000-0002-8022-5319
Gao, Peter0000-0002-8518-9601
Yung, Yuk L.0000-0002-4263-2562
Additional Information:© 2019 Published by Elsevier Ltd. Received 30 August 2019, Revised 4 December 2019, Accepted 5 December 2019, Available online 2 January 2020. We thank Jesse Tarnas, and an anonymous reviewer, for helpful reviews that led to an improved manuscript. We thank Alan Howard, Colin Goldblatt, Ross Irwin, Bob Craddock, Alejandro Soto, John Armstrong, Feng Tian, Itay Halevy, Alex Pavlov, Tom McCollom, Sarah Stewart, and Chris Oze for discussions, and Robin Wordsworth for sharing model output. The MATLAB scripts and GCM summary output used to make the figures in this paper may be obtained for unrestricted further use by contacting the lead author. This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant Agreement No. 832738/ESCAPE. M.T. and E.S.K. acknowledge support from the France And Chicago Collaborating in The Sciences (FACCTS) program. E.S.K. acknowledges funding from NASA (NNX16AG55G). CRediT authorship contribution statement: Edwin S. Kite: Conceptualization, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Software, Visualization, Writing - original draft, Writing - review & editing. Michael A. Mischna: Investigation, Methodology, Software, Writing - review & editing. Peter Gao: Investigation, Methodology. Yuk L. Yung: Software. Martin Turbet: Investigation. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Group:Astronomy Department
Funding AgencyGrant Number
Marie Curie Fellowship832738
France And Chicago Collaborating in The Sciences (FACCTS)UNSPECIFIED
Record Number:CaltechAUTHORS:20200103-102636749
Persistent URL:
Official Citation:Edwin S. Kite, Michael A. Mischna, Peter Gao, Yuk L. Yung, Martin Turbet, Methane release on Early Mars by atmospheric collapse and atmospheric reinflation, Planetary and Space Science, Volume 181, 2020, 104820, ISSN 0032-0633, (
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:100495
Deposited By: Tony Diaz
Deposited On:05 Jan 2020 00:17
Last Modified:16 Nov 2021 17:54

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