Protocol for a Last Interglacial Antarctic ice-sheet model inter-comparison

During the last interglacial, geological records show evidence that the sea level peaked between 6 and 9 m above pre-industrial sea level, with a major contribution from the Antarctic ice sheet. However, ice-sheet models give a very large range of values due to a lack of understanding of the mechanisms leading to the Antarctic ice sheet retreat during the Last Interglacial Here, we propose a protocol to apply systematically to multiple ice-sheet models to better understand the climate and ice-sheet model uncertainties as well as mechanisms leading to a smaller Antarctic ice sheet. We present the climate forcing choices and methodology, ice-sheet model requirements and the group of simulations suggested. The protocol includes transient penultimate deglaciation and last interglacial equilibrium simulations to make it accessible to all types of ice-sheet models. The protocol includes also sensitivity experiments such as hosing. Inputs from the community are welcome to improve the protocol under development and make it relevant to all ice-sheet modelling groups interested in participating!