Sensitivity of the Antarctic ice sheets to the peak warming of Marine Isotope Stage 11
Studying the response of the Antarctic ice sheets to past climate conditions similar to the present day can provide important insights for understanding its current changes and help identify natural drivers of ice sheet retreat. The Marine Isotope Substage 11c (MIS11c) interglacial is one of the bes...
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ftcopernicus:oai:publications.copernicus.org:tcd85196 2023-05-15T13:55:28+02:00 Sensitivity of the Antarctic ice sheets to the peak warming of Marine Isotope Stage 11 Mas e Braga, Martim Bernales, Jorge Prange, Matthias Stroeven, Arjen P. Rogozhina, Irina 2020-05-25 application/pdf https://doi.org/10.5194/tc-2020-112 https://tc.copernicus.org/preprints/tc-2020-112/ eng eng doi:10.5194/tc-2020-112 https://tc.copernicus.org/preprints/tc-2020-112/ eISSN: 1994-0424 Text 2020 ftcopernicus https://doi.org/10.5194/tc-2020-112 2020-07-20T16:22:09Z Studying the response of the Antarctic ice sheets to past climate conditions similar to the present day can provide important insights for understanding its current changes and help identify natural drivers of ice sheet retreat. The Marine Isotope Substage 11c (MIS11c) interglacial is one of the best candidates for an in-depth analysis given that at its later portion orbital parameters were close to our current interglacial. However, Antarctic ice core data indicate that although MIS11c CO 2 levels were close to Pre Industrial, warmer-than-present temperatures (of about 2 °C) lasted for much longer than during other interglacials. Since the global mean sea level is thought to have been 6‐13 m higher than today, there should have been some contribution from Antarctica. While substantial work has been conducted regarding the response of the Greenland Ice Sheet to the MIS11c climate, which is believed to have contributed with 3.9–7.0 m to global sea level, both configurations of the Antarctic ice sheets and their contribution to sea level rise remain poorly constrained. We use a numerical ice-sheet model to shed light on the response of the Antarctic ice sheets to MIS11c climate conditions obtained from a combination of a suite of Antarctic ice cores and the LR04 global stack of deep-sea sediment records and climate model outputs, while assessing the model sensitivity to the uncertainties in sea level reconstructions, ice sheet initial configuration, and multi-centennial climate variability. We found that the regional climate signal of the MIS11c peak warming in Antarctica captured by the ice core records is necessary for the recorded sea level highstand to be reproduced, and that warming length was more important than magnitude. However, there is a threshold for a West Antarctic Ice Sheet collapse that lies within an envelope of 1.6 and 2.1 °C warmer-than-pre-industrial regional climate conditions. Sea level forcing and multi-centennial variability were found to have played virtually no role in driving ice sheet contraction, but the choice of initial configuration of the East Antarctic Ice Sheet provided a large source of uncertainty in the quantification of MIS11c Antarctic peak sea level contribution, which falls between 6.4 and 8.8 m. Text Antarc* Antarctic Antarctica Greenland ice core Ice Sheet Copernicus Publications: E-Journals Antarctic East Antarctic Ice Sheet Greenland The Antarctic West Antarctic Ice Sheet |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
Studying the response of the Antarctic ice sheets to past climate conditions similar to the present day can provide important insights for understanding its current changes and help identify natural drivers of ice sheet retreat. The Marine Isotope Substage 11c (MIS11c) interglacial is one of the best candidates for an in-depth analysis given that at its later portion orbital parameters were close to our current interglacial. However, Antarctic ice core data indicate that although MIS11c CO 2 levels were close to Pre Industrial, warmer-than-present temperatures (of about 2 °C) lasted for much longer than during other interglacials. Since the global mean sea level is thought to have been 6‐13 m higher than today, there should have been some contribution from Antarctica. While substantial work has been conducted regarding the response of the Greenland Ice Sheet to the MIS11c climate, which is believed to have contributed with 3.9–7.0 m to global sea level, both configurations of the Antarctic ice sheets and their contribution to sea level rise remain poorly constrained. We use a numerical ice-sheet model to shed light on the response of the Antarctic ice sheets to MIS11c climate conditions obtained from a combination of a suite of Antarctic ice cores and the LR04 global stack of deep-sea sediment records and climate model outputs, while assessing the model sensitivity to the uncertainties in sea level reconstructions, ice sheet initial configuration, and multi-centennial climate variability. We found that the regional climate signal of the MIS11c peak warming in Antarctica captured by the ice core records is necessary for the recorded sea level highstand to be reproduced, and that warming length was more important than magnitude. However, there is a threshold for a West Antarctic Ice Sheet collapse that lies within an envelope of 1.6 and 2.1 °C warmer-than-pre-industrial regional climate conditions. Sea level forcing and multi-centennial variability were found to have played virtually no role in driving ice sheet contraction, but the choice of initial configuration of the East Antarctic Ice Sheet provided a large source of uncertainty in the quantification of MIS11c Antarctic peak sea level contribution, which falls between 6.4 and 8.8 m. |
format |
Text |
author |
Mas e Braga, Martim Bernales, Jorge Prange, Matthias Stroeven, Arjen P. Rogozhina, Irina |
spellingShingle |
Mas e Braga, Martim Bernales, Jorge Prange, Matthias Stroeven, Arjen P. Rogozhina, Irina Sensitivity of the Antarctic ice sheets to the peak warming of Marine Isotope Stage 11 |
author_facet |
Mas e Braga, Martim Bernales, Jorge Prange, Matthias Stroeven, Arjen P. Rogozhina, Irina |
author_sort |
Mas e Braga, Martim |
title |
Sensitivity of the Antarctic ice sheets to the peak warming of Marine Isotope Stage 11 |
title_short |
Sensitivity of the Antarctic ice sheets to the peak warming of Marine Isotope Stage 11 |
title_full |
Sensitivity of the Antarctic ice sheets to the peak warming of Marine Isotope Stage 11 |
title_fullStr |
Sensitivity of the Antarctic ice sheets to the peak warming of Marine Isotope Stage 11 |
title_full_unstemmed |
Sensitivity of the Antarctic ice sheets to the peak warming of Marine Isotope Stage 11 |
title_sort |
sensitivity of the antarctic ice sheets to the peak warming of marine isotope stage 11 |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-2020-112 https://tc.copernicus.org/preprints/tc-2020-112/ |
geographic |
Antarctic East Antarctic Ice Sheet Greenland The Antarctic West Antarctic Ice Sheet |
geographic_facet |
Antarctic East Antarctic Ice Sheet Greenland The Antarctic West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Antarctica Greenland ice core Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica Greenland ice core Ice Sheet |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-2020-112 https://tc.copernicus.org/preprints/tc-2020-112/ |
op_doi |
https://doi.org/10.5194/tc-2020-112 |
_version_ |
1766262089239756800 |