Modeling Neoproterozoic Snowball Earth Sensitivity

Low-latitude glacial deposits at sea-level suggest that there may have been snowball Earth conditions in the late Proterozoic. We use an Earth System model of intermediate complexity, including an ocean GCM sub-component, to conduct a series of experiments simulating Neoproterozoic climate conditions using an 18 hour day-length and a 6% reduction of the solar constant. This study uses three different orientations of an idealized supercontinent; one centered at the equator, one stretched from pole to pole, and one situated at the south pole. We vary albedo, atmospheric CO₂ and orbital forcings to produce a wide range of climate conditions. Our results indicate that for a set of realistic Neoproterozoic forcings it is possible to simulate either complete snowball Earth conditions, where the ocean is completely covered in ice, or partial 'oasis' snowball conditions, where there is an equatorial band of open water.