Initialization and Projection of the Greenland Ice Sheet with the PoLarIS model

This study presents the application of the Polar Land Ice Simulator (PoLarIS) to initialize and project the dynamics of the Greenland Ice Sheet (GrIS). Accurately simulating the GrIS is critical for predicting its contribution to sea-level rise, yet challenges persist in representing its present-day state and future evolution. The initialization of the PoLarIS model leverages advanced data assimilation techniques, integrating high-resolution satellite and airborne observations to constrain the initial ice geometry, velocity, and basal conditions, thereby reducing discrepancies with the observed present-day ice sheet configuration. For projecting future dynamics, the model incorporates key physical processes, including thermomechanical coupling and evolving basal conditions, to simulate ice flow and mass balance under different climatic scenarios. The simulations highlight the significant role of marine-terminating outlet glaciers and the sensitivity of the ice sheet to oceanic and atmospheric forcings. Results underscore the importance of accurate initialisation for reliable centennial-scale projections and demonstrate the PoLarIS model's capability in contributing to improved estimates of the GrIS's future mass loss