MAGIC-DML Measuring/Mapping/Modeling Antarctic Geomorphology and Ice Change in Dronning Maud Land: The German ice sheet modeling component
Final Report Abstract
The project aimed at reconstructing ice-surface elevation changes across Antarctica, with a specific focus on Dronning Maud Land (DML), since the mid-Pliocene warm period by merging direct evidence with ice sheet and climate numerical modeling. The joint use of continental-scale and ultra-highresolution regional ice flow models provides additional insight into the glacial history of the Antarctic ice sheet/shelf complex, while the use of a global climate model enables an assessment of its interactions with other Earth sub-systems. The project was the core modeling component of the international collaborative research project MAGIC-DML, an innovative integrated approach creating a bridge between field sciences and numerical modeling. To achieve this goal we have assembled a Swedish-US-German-Norwegian-UK interdisciplinary team, with expertise areas in glaciology, geology, glacial geomorphology, geochronology, climatology, oceanography and numerical modeling. We have established a robust numerical framework integrating ice sheet, atmosphere, and ocean modeling. This framework has provided continental-scale Antarctic Ice Sheet model reconstructions of several past periods. Using the bridge between field sciences and numerical modeling to estimate past volume fluctuations in East Antarctica, we were able to quantify its response to warmer-than-present climate conditions during the Pliocene and previous interglacials like the Marine Isotope Stage (MIS) 11c super-interglacial about 400,000–420,000 years ago. Gained insight into the effects of individual oceanic and atmospheric forcing components on the dynamics of the Antarctic Ice Sheet offered an opportunity to assess the similarity between these past warm periods and present-day/future conditions. As one of the project’s key results, we found a most likely global sea-level contribution from the Antarctic Ice Sheet of 6.7–8.2 m during MIS 11c. The model result further suggests a threshold of modest 0.4°C Southern Ocean intermediate-depth warming that may lead to a collapse of the West Antarctic Ice Sheet if sustained for at least 4000 years. Finally, we found that main ice streams in the DML region react differently to warmer-than-present climate conditions depending on their topographic configuration at a given geological time (e.g. present-day vs. mid-Pliocene), even thickening by hundreds of meters, which highlights the limitations of inferring future ice-sheet behaviour from geological analogies.
Publications
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High climate model dependency of Pliocene Antarctic ice-sheet predictions. Nature Communications, 9(1).
Dolan, Aisling M.; de Boer, Bas; Bernales, Jorge; Hill, Daniel J. & Haywood, Alan M.
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Global environmental consequences of twenty-first-century ice-sheet melt. Nature, 566(7742), 65-72.
Golledge, Nicholas R.; Keller, Elizabeth D.; Gomez, Natalya; Naughten, Kaitlin A.; Bernales, Jorge; Trusel, Luke D. & Edwards, Tamsin L.
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MAGIC-DML: Combining climate and ice sheet modelling with field-based data to reconstruct the long-term glacial history of East Antarctica, 20th Congress of the International Union for Quaternary Research (INQUA), 25–31 Jul 2019
Bernales J; Mas e Braga M; Rogozhina I; Stroeven AP & Prange M
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Ice surface changes during recent glacial cycles along the Jutulstraumen and Penck Trough ice streams in western Dronning Maud Land, East Antarctica. Quaternary Science Reviews, 249(c(2020, 12)), 106636.
Andersen, J.L.; Newall, J.C.; Blomdin, R.; Sams, S.E.; Fabel, D.; Koester, A.J.; Lifton, N.A.; Fredin, O.; Caffee, M.W.; Glasser, Neil F.; Rogozhina, I.; Suganuma, Y.; Harbor, J.M. & Stroeven, A.P.
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A Machine Learning Heat Flow Model of Antarctica. American Geophysical Union (AGU).
Lösing Mareen, Bernales Jorge & Ebbing Jörg
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Nunataks as barriers to ice flow: implications for palaeo ice sheet reconstructions. The Cryosphere, 15(10), 4929-4947.
Mas e Braga, Martim; Selwyn Jones, Richard; Newall, Jennifer C. H.; Rogozhina, Irina; Andersen, Jane L.; Lifton, Nathaniel A. & Stroeven, Arjen P.
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Sensitivity of the Antarctic ice sheets to the warming of marine isotope substage 11c. The Cryosphere, 15(1), 459-478.
Mas e Braga, Martim; Bernales, Jorge; Prange, Matthias; Stroeven, Arjen P. & Rogozhina, Irina
