Simulating the Antarctic ice sheet in the late-Pliocene warm period: PLISMIP-ANT, an ice-sheet model intercomparison project

Published: Jul 1, 2015 by The PISM Authors

Understanding the behaviour of ice sheets during warm intervals in Earth history is of fundamental importance for understanding future climate change. The late Pliocene warm period (3.264–3.025 Ma BP) serves as an analogue for future climates. Although Pliocene ice locations and extents are still poorly constrained, a significant contribution to sea-level rise is expected from the Antarctic ice sheets based on sea-level reconstructions. All six included ice-sheet models in this paper, including PISM v0.6, used the shallow ice and shelf approximations for the complete Antarctic domain, including grounded and floating ice, for both modern control and Pliocene ice sheet runs, in five sensitivity experiments. The models simulate a comparable present-day ice sheet, considering the models use their own parameter settings. For the Pliocene, all six models have difficulty simulating significant retreat or re-advance of the East Antarctic ice grounding line, which is thought to have happened for the Wilkes and Aurora basins. The specific sea-level contribution of the Antarctic ice sheet at this point cannot be conclusively determined. Improved grounding line physics is apparently needed.