GCM sensitivity test using increased rotation rate, reduced solar forcing and orography to examine low latitude glaciation in the Neoproterozoic

Abstract

During the Neoproterozoic period, most landmasses were assembled into the super-continent, Rodinia, and parts experienced glaciation in low paleolatitudes. We examine possible causes of glaciation by increasing rotation rate, reducing the solar constant and carbon dioxide concentrations for an idealized super-continent that is centered in the Northern Hemispehre tropics-subtropics. Further, we introduce a 2 km north-south mountain chain in the western regions of this super-continent. A mixed layer ocean or prescribed time varying sea surface temperatures are used in these simulations. Our results show that neither an individual factor or a combination of these factors can cool temperatures enough to bring about glaciation on the tropical super-continent. We conclude that other factors would be needed to initiate glaciation.