under a Creative Commons License. Climate of the Past Climatic Conditions for modelling the Northern Hemisphere ice

Abstract. The ice sheet-climate interaction as well as the cli-matic response to orbital parameters and atmospheric CO2 concentration are examined in order to drive an ice sheet model throughout an ice age cycle. Feedback processes be-tween ice sheet and atmosphere are analyzed by numeri-cal experiments using a high resolution General Circulation Model (GCM) under different conditions at the Last Glacial Maximum. Among the proposed processes, the ice albedo feedback, the elevation-mass balance feedback and the de-sertification effect over the ice sheet were found to be the dominant processes for the ice-sheet mass balance. For the elevation-mass balance feedback, the temperature lapse rate over the ice sheet is proposed to be weaker than assumed in previous studies. Within the plausible range of parame-ters related to these processes, the ice sheet response to the orbital parameters and atmospheric CO2 concentration for the last glacial/interglacial cycle was simulated in terms of both ice volume and geographical distribution, using a three-dimensional ice-sheet model. Careful treatment of climate-ice sheet feedback is essential for a reliable simulation of the ice sheet changes during ice age cycles.