Projections of Antarctic ice sheet evolution over the 21st century from the Ice Sheet Model Intercomparison for CMIP6 (ISMIP6)

ISMIP6 (Ice Sheet Model Intercomparision Project for CMIP6) is the primary activity within the Coupled Model Intercomparison Project - phase 6 (CMIP6) focusing on the Greenland and Antarctic Ice Sheets. Ice sheets interact dynamically with the other components of the climate system, and ice flow model simulations are strongly influenced by the ocean and atmosphere. Including evolving ice sheets in Global Climate Model (GCM) simulations would therefore be the method of choice to study ice sheets as an integral part of the climate system. However, ice sheet models are only starting now to be integrated as a component of GCMs and alternative methods are therefore needed to estimate the impact of future climatic changes on ice sheets evolution. Furthermore, the accuracy and spatial resolution in oceanic and atmospheric conditions needed to constrain such ice sheet models are not always achieved by GCM simulations, which complicates the coupling between these components. In this presentation, we describe how we use results from GCMs to either directly constrain or derive parameterizations for oceanic and atmospheric forcings for ice sheet simulations of ISMIP6 Antarctic standalone experiments. We then present the results of the ISMIP6 Antarctic Projections over the 21^stcentury. We analyze the impact of external forcings and model parameterization on the evolution of Antarctica over the coming century, and quantify the associated uncertainties.

Research was performed at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Funding was provided by grants from the NASA Cryospheric Science and Modeling, Analysis and Prediction Programs.