A framework for three-dimensional dynamic modeling of mountain glaciers in the Community Ice Sheet Model (CISM v2.2)

Abstract. It is essential to improve our understanding of mountain glaciers and their effects on sea level, ecosystems, and freshwater resources in a changing climate. To this end, we implemented a framework for three-dimensional, high-resolution, regional-scale glacier simulations in the Community Ice Sheet Model (CISM v2.2), using higher-order ice-flow dynamics previously applied to the Greenland and Antarctic ice sheets. Here, we present the modeling framework and its application to the European Alps glaciers at a 100-meter resolution, using protocols from the third phase of the Glacier Model Intercomparison Project (GlacierMIP3). The model results align well with observations and other glacier models, showing that Alpine glaciers will lose nearly half of their present-day area and volume under current climate conditions, with a near-total ice loss expected in warmer scenarios. This new development integrates glacier and ice sheet systems in a common modeling framework and will support advances in coupled land ice – Earth system assessments across timescales in the Community Earth System Model (CESM).