GMD Geoscientific Model Development GMD Geosci. Model Dev. 1991-9603 Copernicus Publications Göttingen, Germany 10.5194/gmd-5-963-2012 Pliocene Ice Sheet Modelling Intercomparison Project (PLISMIP) – experimental design Dolan A. M. 1 4 Koenig S. J. 2 4 Hill D. J. 1 3 Haywood A. M. 1 DeConto R. M. 2 School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK Department of Geosciences, University of Massachusetts, Amherst, MA 01003, USA British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK These authors contributed equally to this work. 18 07 2012 5 4 963 974 Copyright: © 2012 A. M. Dolan et al. 2012 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://gmd.copernicus.org/articles/5/963/2012/gmd-5-963-2012.html The full text article is available as a PDF file from https://gmd.copernicus.org/articles/5/963/2012/gmd-5-963-2012.pdf

During the mid-Pliocene warm period (3.264 to 3.025 million years ago), global mean temperature was similar to that predicted for the next century and atmospheric carbon dioxide concentrations were slightly higher than today. Sea level was also higher than today, implying a reduction in the extent of the ice sheets. Thus, the mid-Pliocene warm period (mPWP) provides a unique testing ground to investigate the stability of the Earth's ice sheets and their contribution to sea level in a warmer-than-modern world. Climate models and ice sheet models can be used to enhance our understanding of ice sheet stability; however, uncertainties associated with different ice-sheet modelling frameworks mean that a rigorous comparison of numerical ice sheet model simulations for the Pliocene is essential. As an extension to the Pliocene Model Intercomparison Project (PlioMIP; Haywood et al., 2010, 2011a), the Pliocene Ice Sheet Modelling Intercomparison Project (PLISMIP) will provide the first assessment as to the ice sheet model dependency of ice sheet predictions for the mPWP. Here we outline the PLISMIP experimental design and initialisation conditions that have been adopted to simulate the Greenland and Antarctic ice sheets under present-day and warm mid-Pliocene conditions. Not only will this project provide a new benchmark in the simulation of ice sheets in a past warm period, but the analysis of model sensitivity to various uncertainties could directly inform future predictions of ice sheet and sea level change.

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