Exploring ice-atmosphere feedbacks in Antarctica using coupled simulations

• ²Laboratory of climatology, SPHERES research unit, Department of Geography, University of Liège, Liège, Belgium
• ³Physical Geography Research Group, Department of Geography, Vrije Universiteit Brussel, Brussels, Belgium

Accurate projections of the Antarctic ice sheet contribution to future sea-level rise require a robust representation of ice–atmosphere interactions and associated surface mass balance (SMB) feedbacks. Although they remain computationally expensive, coupled ice–atmosphere simulations provide the ideal framework for capturing these processes.
In this work in progress, we present ongoing coupled simulations between the ice-sheet model Kori-ULB and the regional climate model MAR. The coupled Kori-MAR simulations are conducted over Antarctica for the period 1980–2100 and are forced by the IPSL-CM6A-LR climate model under the SSP5-8.5 scenario. We compare the coupled simulations with three simplified modelling approaches: (i) ice-sheet model experiments externally forced by MAR outputs assuming a fixed ice-sheet geometry, (ii) simulations using a positive degree-day (PDD) scheme forced directly by IPSL-CM6A-LR, and (iii) simulations using a PDD scheme forced by MAR(IPSL-CM6A-LR). This allows us to investigate the influence of ice geometry changes on Antarctic SMB and projected ice-sheet mass loss. In parallel, we assess the ability of simplified SMB methods to reproduce MAR-derived SMB fields and their temporal evolution. A key objective is to better constrain the melt–elevation feedback emerging in the coupled simulations and to use this information to calibrate and improve PDD-based approaches for long-term Antarctic ice-sheet projections.