Robust elements of Snowball Earth atmospheric circulation and oases for life

Dorian S. Abbot, Aiko Voigt, Dawei Li, Guillaume Le Hir, Raymond T. Pierrehumbert, Mark Branson, David Pollard, Daniel D. Daniel

Research output: Contribution to journalArticle

21 Scopus citations

Abstract

Atmospheric circulation in a Snowball Earth is critical for determining cloud behavior, heat export from the tropics, regions of bare ice, and sea glacier flow. These processes strongly affect Snowball Earth deglaciation and the ability of oases to support photosynthetic marine life throughout a Snowball Earth. Here we establish robust aspects of the Snowball Earth atmospheric circulation by running six general circulation models with consistent Snowball Earth boundary conditions. The models produce qualitatively similar patterns of atmospheric circulation and precipitation minus evaporation. The strength of the Snowball Hadley circulation is roughly double modern at low CO2 and greatly increases as CO2 is increased. We force a 1-D axisymmetric sea glacier model with general circulation model (GCM) output and show that, neglecting zonal asymmetry, sea glaciers would limit ice thickness variations to O(10%). Global mean ice thickness in the 1-D sea glacier model is well-approximated by a 0-D ice thickness model with global mean surface temperature as the upper boundary condition. We then show that a thin-ice Snowball solution is possible in the axysymmetric sea glacier model when forced by output from all the GCMs if we use ice optical properties that favor the thin-ice solution. Finally, we examine Snowball oases for life using analytical models forced by the GCM output and find that conditions become more favorable for oases as the Snowball warms, so that the most critical time for the survival of life would be near the beginning of a Snowball Earth episode. Key Points Snowball Hadley cell is stronger than modern and increases with CO2 in six GCMs GCMs produce a similar Snowball P-E pattern with net ablation in the tropics Sea glacier thickness variations and oases are more favorable as Snowball ages

Original languageEnglish (US)
Pages (from-to)6017-6027
Number of pages11
JournalJournal of Geophysical Research Atmospheres
Volume118
Issue number12
DOIs
StatePublished - Jun 27 2013

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All Science Journal Classification (ASJC) codes

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

Cite this

Abbot, D. S., Voigt, A., Li, D., Hir, G. L., Pierrehumbert, R. T., Branson, M., Pollard, D., & Daniel, D. D. (2013). Robust elements of Snowball Earth atmospheric circulation and oases for life. Journal of Geophysical Research Atmospheres, 118(12), 6017-6027. https://doi.org/10.1002/jgrd.50540