Neoproterozoic "snowball Earth": Dynamic sea ice over a quiescent ocean

Low-latitude sea level glacial deposits suggest the existence of "snowball Earth" conditions in the Neoproterozoic. Previous modeling studies have offered conflicting support for the snowball hypothesis. We use a climate model of intermediate complexity, including an ocean GCM and a sophisticated thermodynamic/dynamic sea ice component, to conduct a suite of experiments with different orbital/paleogeographical configurations, wind-forcing, and atmospheric CO2 levels. We show that depending on the orbital configuration and paleogeography, snowball conditions prevail even with atmospheric CO2 levels up to 1800 ppmv. Overall, our modeling paradigm is consistent with the original snowball hypothesis in which an ice covered ocean surrounds a largely snow and ice-free barren land, with some coastal regions permitting the growth of thick glaciers.