An open ocean region in Neoproterozoic glaciations would have to be narrow to allow equatorial ice sheets

Abstract

[1] A major goal of understanding Neoproterozoic glaciations and determining their effect on the evolution of life and Earth's atmosphere is establishing whether and how much open ocean there was during them. Geological evidence tells us that continental ice sheets had to flow into the ocean near the equator during these glaciations. Here we drive the Parallel Ice Sheet Model with output from four simulations of the ECHAM5/Max Planck Institute Ocean Model atmosphere-ocean general circulation model with successively narrower open ocean regions. We find that extensive equatorial ice sheets form on marine margins if sea ice extends to within about 20 ı latitude of the equator or less (Jormungand-like and hard snowball states), but do not form if there is more open ocean than this. Given uncertainty in topographical reconstruction and ice sheet ablation parameterizations, we perform extensive sensitivity tests to confirm the robustness of our main conclusions. Citation: Rodehacke, C. B., A. Voigt, F. Ziemen, and D. S. Abbot (2013), An open ocean region in Neoproterozoic glaciations would have to be narrow to allow equatorial ice sheets, Geophys. Res. Lett., 40,[5503][5504][5505][5506][5507]

Habitable Snowballs: Temperate Land Conditions, Liquid Water, and Implications for CO2 Weathering

“…In an extension of that work, Hoffman et al () found the deglaciated areas in Benn et al () were able to occasionally reach above‐freezing temperatures. In contrast, using different models, Donnadieu et al () and Rodehacke et al () were unable to produce deglaciated land in other Snowball Earth experiments, suggesting that the details of the ice sheet model matter and are one of the key caveats of our results. Our goal was to use a simple approach to identify the impact that ice sheet elevation could have on our results and find that very large ice sheets are a problem, but thinner ice sheets may not be.…”

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“…10.1029/2019JE005917 snowball events (e.g., Kirschvink, 1992;Lewis et al, 2007;Rodehacke et al, 2013;Yang et al, 2012), but in PlaSim, snowballs are characterized by complete sea ice cover, and exit from a snowball event begins when sea ice starts to melt, triggering an albedo feedback runaway. Sea ice thickness is limited to 9 m, but we do not restrict the depth of land ice and snow.…”

Refugium for surface life on Snowball Earth in a nearly enclosed sea? A numerical solution for sea-glacier invasion through a narrow strait

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Snowball Earth climate dynamics and Cryogenian geology-geobiology

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