Earlier large-scale Greenland ice sheet experiments e.g. those run during ice2sea and SeaRISE initiatives have shown that ice sheet initialisation can have a large effect on sea-level projections and gives rise to important uncertainties. Improving initialisation techniques is currently a field of active research, which makes it difficult to prescribe one technique as the method of choice for ISMIP6. Instead, we first propose a “Come as you are”- approach, which allows participants to contribute with their currently used model setup and initialisation technique for intercomparison (initMIP). This, we hope, allows getting modellers involved early in the ISMIP6 process and keeps the workload for participants as low as possible. Furthermore, the proposed schematic experiments may facilitate to document on-going model development. Starting early in the CMIP6 process implies relying on schematic forcing for the initiation experiments that is independent from CMIP6 AOGCM output, which will only become available later on. The initMIP-Greenland is the first in a series of ISMIP6 ice sheet model intercomparison activities and is led by Heiko Goelzer.
• Compare and evaluate the initialisation methods used in the ice sheet modelling community
• Estimate uncertainty associated with initialisation
• Get the ice sheet modelling community started with ISMIP6 activities
• Document on-going model development, as the simple experiments could be repeated with new model versions