Linear sea-level response to abrupt ocean warming of major West Antarctic ice basin

Published: Nov 1, 2015 by The PISM Authors

   
Title Linear sea-level response to abrupt ocean warming of major West Antarctic ice basin
Authors M. Mengel, J. Feldmann, and A. Levermann
Venue Nature Climate Change

This paper might best be understood as the second of three studies, by these authors, of three Antarctic ice sheet/shelf basins. These basins are among the biggest and, before studying their properties in detail, the most potentially unstable. But the PISM model results do not suggest all of these basins act the same. The first of these papers, M. Mengel and A. Levermann (2014) “Ice plug prevents irreversible discharge from East Antarctica”, suggests that the Wilkes basin is likely to destabilize under sufficient forcing to remove a certain (quantified) amount of near-ocean ice, but that the time scale of destabilization is long. The third of these papers, J. Feldmann and A. Levermann (2015) “Collapse of the West Antarctic Ice Sheet after local destabilization of the Amundsen Basin”, which just appeared in November 2015, demonstrates the fast, and very large in magnitude, destabilization of the whole of WAIS from an Amundsen Sea basin forcing. The current paper suggests that, by contrast, the Filchner-Ronne basin is essentially stable in the sense that the forcing dominates its response. Ocean models do indicate an abrupt intrusion of warm circumpolar deep water into the cavity below the Filchner–Ronne ice shelf within the next two centuries. The basin’s retrograde bed slope would allow for an unstable ice-sheet retreat, but the buttressing of the large ice shelf and the narrow glacier troughs tend to inhibit such instability. This paper’s main result, as shown in the graph at left, is that buttressing “wins”. Stronger forcing (“shelf melting”) generates greater ice loss, but there is no tipping point as with the other basins. The response is roughly linear.

Share

Latest news

Version 1.2

We are pleased to announce the release of the Parallel Ice Sheet Model (PISM) v1.2.

MPI-M Hamburg, Germany: open postdoc for coupled atmosphere-ocean-ice sheet model

The Max Planck Institute for Meteorology (MPI-M) contributes to the BMBF project “From the Last Interglacial to the Anthropocene: Modeling a Complete Glacial Cycle” (PalMod, www.palmod.de), which aims at simulating the climate from the peak of the last interglacial up to the present using comprehensive Earth System Models. Phase II of this project has an open position Postdoctoral Scientist (W073). The successful candidate will be part of a local team performing and analysing long-term transient simulations covering the last glacial and the transition into the Holocene with an interactively coupled atmosphere-ocean-ice sheet model. Additionally, the candidate will contribute to the continued development of this model. The model system consists of the MPI-Earth system model, the ice sheet model PISM, and the solid-earth model VILMA.

AWI PostDoc: Antarctic Ice Sheets in warming climates

Dr. Lohmann’s group at AWI is seeking a postdoc to work with PISM and the multi-scale Earth system model AWI-ESM. See