PISM-VILMA glacial cycle simulations of the Antarctic Ice Sheet coupled to the solid Earth and global sea level

The dynamics of the ice sheets on glacial time scales are highly controlled by interactions with the solid Earth, i.e., the glacial isostatic adjustment (GIA). Particularly at marine ice sheets, competing feedback mechanisms govern the migration of the ice sheet's grounding line (GL) and hence the ice sheet stability. We performed a suite of coupled ice sheet–solid Earth simulations over the last two glacial cycles. To represent ice sheet dynamics we apply the Parallel Ice Sheet Model PISM and to represent the solid Earth response we apply the three-dimensional viscoelastic Earth model VILMA, which, in addition to load deformation and rotation changes, considers the gravitationally consistent redistribution of water (the sea-level equation). With our coupling setup we evaluate the relevance of feedback mechanisms for the glaciation and deglaciation phases in Antarctica considering different 3D Earth structures resulting in a range of load-response time scales.