TY - JOUR T1 - An open ocean region in Neoproterozoic glaciations would have to be narrow to allow equatorial ice sheets JF - Geophysical Research Letters Y1 - 2013 A1 - Rodehacke, Christian B. A1 - Voigt, Aiko A1 - Ziemen, Florian A1 - Abbot, Dorian S. KW - ice sheet modeling KW - Neoproterozoic glaciations KW - snowball Earth AB - 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° 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. VL - 40 UR - http://dx.doi.org/10.1002/2013GL057582 ER -