Using SciDAC Ice Sheet Models to Simulate Antarctica's 21st Century Evolution and Sea Level Rise Contribution
DOE SciDAC’s MALI ice sheet model is part of a multi-model intercomparison focused on better assessing the evolution and sea-level contribution of Antarctica during the 21st century. MALI simulation results represent the highest-resolution, highest fidelity, and most computationally ambitious simulations contributed to this intercomparison effort.
The CMIP6-coordinated Antarctic evolution and sea-level rise experiments conducted here will be used to inform the IPCC's AR6 report. The combination of multiple ice sheet and climate models used here provides estimates for the sensitivity and uncertainties resulting from choice of ice sheet model, climate model, and the current parameterizations and simplifications involved in ice sheet and climate coupling.
Ice flow models of the Antarctic ice sheet are commonly used to simulate its future evolution in response to different climate scenarios and to assess the mass loss that would contribute to future sea-level rise. This study presents results from ice flow model simulations from 13 international groups focusing on the evolution of the Antarctic ice sheet during the period 2015–2100. The ice sheet models evolve in response to outputs from a subset of coupled climate models in order to account for the spread in climate model results. Simulations of the Antarctic ice sheet contribution to sea-level rise in response to increased warming during this period varies between −7.8 and 30.0 cm of sea-level equivalent (SLE) under a high emissions scenario (RCP 8.5). The simulated evolution of the West Antarctic ice sheet varies widely among models, with an overall mass loss, up to 18.0 cm SLE, in response to changes in oceanic conditions. Simulated East Antarctica mass change varies between −6.1 and 8.3 cm SLE, with a significant increase in surface mass balance outweighing the increased ice discharge.