Changing Spatial Distribution Of Water Flow Charts Major Change In Mars' Greenhouse Effect

By Keith Cowing
June 1, 2022
Filed under
Changing Spatial Distribution Of Water Flow Charts Major Change In Mars' Greenhouse Effect
Changing spatial distribution of water flow on Mars. Top: Distribution of >3.6 Ga (Late Noachian / Early Hesperian, LN/EH) rivers (17). Color: river elevation. Gray: excluded region (low/no detection probability). Rivers plotting within gray region are shown by black dots. Rovers: C=Curiosity at Gale crater, P=Perseverance at Jezero crater, T-1=Tianwen-1 rover (Zhurong). Elevation contour spacing is 3 km. Bottom: Distribution of <3.6 Ga (Late Hesperian / Amazonian, LH/A) rivers (18).

Early Mars had rivers, but the cause of Mars’ wet-to-dry transition remains unknown. Past climate on Mars can be probed using the spatial distribution of climate-sensitive landforms.

We analyzed global databases of water-worked landforms and identified changes in the spatial distribution of rivers over time. These changes are simply explained by comparison to a simplified meltwater model driven by an ensemble of global climate model simulations, as the result of ≳10 K global cooling, from global average surface temperature (T) ≥ 268 K to T ∼ 258 K, due to a weaker greenhouse effect.

In other words, river-forming climates on Early Mars were warm and wet first, and cold and wet later. Surprisingly, analysis of the greenhouse effect within our ensemble of global climate model simulations suggests that this shift was primarily driven by waning non-CO2 radiative forcing, and not changes in CO2 radiative forcing.

Edwin S. Kite, Michael A. Mischna, Bowen Fan, Alexander M. Morgan, Sharon A. Wilson, Mark I. Richardson

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Atmospheric and Oceanic Physics (; Geophysics (physics.geo-ph)
Cite as: arXiv:2206.00036 [astro-ph.EP] (or arXiv:2206.00036v1 [astro-ph.EP] for this version)
Focus to learn more
Journal reference: Science Advances 8(21), (2022)
Related DOI:
Focus to learn more
Submission history
From: Edwin Kite
[v1] Tue, 31 May 2022 18:19:40 UTC (13,704 KB)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻