Submitted as: model description paper | 08 Sep 2020
Review status: a revised version of this preprint was accepted for the journal GMD and is expected to appear here in due course.
The Utrecht Finite Volume Ice-Sheet Model: UFEMISM (version 1.0)
Constantijn J. Berends1,Heiko Gölzer1,2,a,and Roderik S. W. van de Wal1,3Constantijn J. Berends et al.Constantijn J. Berends1,Heiko Gölzer1,2,a,and Roderik S. W. van de Wal1,3
Received: 26 Aug 2020 – Accepted for review: 01 Sep 2020 – Discussion started: 08 Sep 2020
Abstract. Improving our confidence in future projections of sea-level rise requires models that can simulate ice-sheet evolution both in the future and in the geological past. A physically accurate treatment of large changes in ice-sheet geometry requires a proper treatment of processes near the margin, like grounding line dynamics, which in turn requires a high spatial resolution in that specific region. This leads to a demand for computationally efficient models, where such a high resolution can be feasibly applied in simulations of 105–107 yr in duration. Here, we present and evaluate a new ice-sheet model that solves the SIA and SSA approximations of the stress balance on a fully adaptive, unstructured triangular mesh. This strongly reduces the number of grid points where the equations need to be solved, increasing the computational efficiency. We show that the model reproduces the analytical solutions or model intercomparison benchmarks for a number of schematic ice-sheet configurations, indicating that the numerical approach is valid. Because of the unstructured triangular mesh, the number of vertices increases less rapidly with resolution than in a square-grid model, greatly reducing the required computation time for high resolutions. A simulation of all four continental ice sheets during an entire 120 kyr glacial cycle, with a 4 km resolution near the grounding line, is expected to take 100–200 wall clock hours on a 16-core system (1,600–3,200 core hours), implying that this model can be feasibly used for high-resolution paleo-ice-sheet simulations.
The largest uncertainty in projections of sea-level rise comes from ice-sheet retreat. To better understand how these ice sheets respond to the changing climate, ice sheet models are used, which must be able to reproduce both their present and past evolution. We have created a model that is fast enough to simulate an ice sheet at a high resolution over the course of an entire 120,000-yr glacial cycle. This allows us to study processes that cannot be captured by lower-resolution models.
The largest uncertainty in projections of sea-level rise comes from ice-sheet retreat. To better...