Patterson, V.L. orcid.org/0000-0001-5763-1848, Gregoire, L.J. orcid.org/0000-0003-0258-7282, Ivanovic, R.F. orcid.org/0000-0002-7805-6018 et al. (6 more authors) (2024) Contrasting the Penultimate Glacial Maximum and the Last Glacial Maximum (140 and 21 ka) using coupled climate–ice sheet modelling. Climate of the Past, 20 (10). pp. 2191-2218. ISSN 1814-9324
Abstract
The configuration of the Northern Hemisphere ice sheets during the Penultimate Glacial Maximum differed to the Last Glacial Maximum. However, the reasons for this are not yet fully understood. These differences likely contributed to the varied deglaciation pathways experienced following the glacial maxima and may have had consequences for the interglacial sea level rise. To understand the differences between the North American Ice Sheet at the Last and Penultimate glacial maxima (21 and 140 ka), we perform two perturbed-physics ensembles of 62 simulations using a coupled atmosphere–ice sheet model, FAMOUS-ice, with prescribed surface ocean conditions, in which the North American and Greenland ice sheets are dynamically simulated with the Glimmer ice sheet model. We apply an implausibility metric to find ensemble members that match reconstructed ice extent and volumes at the Last and Penultimate glacial maxima. We use a resulting set of “plausible” parameters to perform sensitivity experiments to decompose the role of climate forcings (orbit, greenhouse gases) and initial conditions on the final ice sheet configurations. This confirms that the initial ice sheet conditions used in the model are extremely important in determining the difference in final ice volumes between both periods due to the large effect of the ice–albedo feedback. In contrast to evidence of a smaller Penultimate North American Ice Sheet, our results show that the climate boundary conditions at these glacial maxima, if considered in isolation, imply a larger Penultimate Glacial Maximum North American Ice Sheet than at the Last Glacial Maximum by around 6 m sea level equivalent. This supports the notion that the growth of the ice sheet prior to the glacial maxima is key in explaining the differences in North American ice volume.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © Author(s) 2024. This is an open access article under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) |
Funding Information: | Funder Grant number RCUK (Research Councils UK) MR/S016961/1 NERC (Natural Environment Research Council) NE/T007443-1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 15 Oct 2024 11:19 |
Last Modified: | 11 Dec 2024 15:56 |
Status: | Published |
Publisher: | European Geosciences Union |
Identification Number: | 10.5194/cp-20-2191-2024 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:218355 |