Role of sea ice feedbacks in climate changes simulated with an idealized GCM

We investigate the interaction between sea ice feedbacks and atmospheric processes in amplifying the climate response to changes in atmospheric greenhouse gas concentrations and orbital forcing. An idealized aquaplanet GCM that includes a sea ice component is subjected to (i) changes in atmospheric longwave opacity and (ii) changes in top-of-atmosphere insolation representing Earth's orbital configuration during the Pleistocene. We examine how the sea ice cover depends on the climate regime. We also examine how sea ice feedbacks affect changes in atmospheric poleward moisture transport and in the ITCZ position. Physical mechanisms responsible for the simulated changes are discussed.