The Ice-sheet and Sea-level System Model (ISSM) is the result of a collaboration between the Jet Propulsion Laboratory and University of California at Irvine. Its purpose is to tackle the challenge of modeling the evolution of the cryosphere and hydrosphere, with emphasis on the polar ice caps in Greenland and Antarctica, and the resulting solid-Earth and sea-level response. ISSM is open source and is funded by the NASA Cryosphere, N-SLCT (Sea Level Change Sciecne Team), IceBridge Research, ICESat-2 Science Team, GRACE-FO Science Team, ESI (Earth Surface and Interior), and MAP (Modeling Analysis and Prediction) programs, JPL R&TD (Research, Technology and Development) and the National Science Foundation.
As synthesized in the Intergovernmental Panel on Climate Change (IPCC) Assessment Report AR5, "significant uncertainties remain, particularly related to the magnitude and rate of the ice-sheet contribution for the 21st century and beyond". To address the urgency of delivering reliable sea-level projections to policy makers, large-scale ice flow models like ISSM serve as critical tools for scientists. Such models help scientists provide accurate predictions of how the Greenland and Antarctic Ice Sheets, and other permanent land ice, may evolve in response to climate warming and contribute to sea-level change around the globe. In order to improve projections of future sea-level, ISSM relies on state-of-the-art technologies including finite element modeling, higher-order ice dynamics, parallel technologies, anisotropic mesh refinement, data assimilation, and uncertainty quantification.