Steady-state characteristics of the Greenland ice sheet under different climates

Abstract The Greenland ice sheet is modelled to simulate its extent and volume in warmer climates, and to find out whether the ice sheet would re-form on the ice-free bedrock under present climatic conditions. The ice-sheet model is a three-dimensional thermo-mechanical model with a fine-resolution grid. The bedrock surface beneath the ice sheet was mapped using radio-echo-sounding measurements by the Electromagnetic Institute, Copenhagen. The model experiments show that increased temperature will result in ice-margin retreat, but the ice sheet is relatively stable; it takes a temperature rise of at least 6 deg for the ice sheet to disappear completely, which indicates that the ice sheet probably survived the last interglacial. Furthermore, it appears that the Greenland ice sheet is not a mere relict ice mass from a previously colder climate but that the ice sheet will still re-form on the bare bedrock under the present, or even slightly warmer, climatic conditions.