Global cooling linked to increased glacial carbon storage via changes in Antarctic sea ice
Palaeo-oceanographic reconstructions indicate that the distribution of global ocean water masses has undergone major glacial–interglacial rearrangements over the past ~2.5 million years. Given that the ocean is the largest carbon reservoir, such circulation changes were probably key in driving the v...
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ftnerc:oai:nora.nerc.ac.uk:526522 2023-05-15T13:41:44+02:00 Global cooling linked to increased glacial carbon storage via changes in Antarctic sea ice Marzocchi, Alice Jansen, Malte F. 2019-10-14 text http://nora.nerc.ac.uk/id/eprint/526522/ https://nora.nerc.ac.uk/id/eprint/526522/1/marzocchi_jansen1.pdf https://doi.org/10.1038/s41561-019-0466-8 en eng https://nora.nerc.ac.uk/id/eprint/526522/1/marzocchi_jansen1.pdf Marzocchi, Alice orcid:0000-0002-3430-3574 Jansen, Malte F. 2019 Global cooling linked to increased glacial carbon storage via changes in Antarctic sea ice. Nature Geoscience, 12 (12). 1001-1005. https://doi.org/10.1038/s41561-019-0466-8 <https://doi.org/10.1038/s41561-019-0466-8> Publication - Article PeerReviewed 2019 ftnerc https://doi.org/10.1038/s41561-019-0466-8 2023-02-04T19:49:58Z Palaeo-oceanographic reconstructions indicate that the distribution of global ocean water masses has undergone major glacial–interglacial rearrangements over the past ~2.5 million years. Given that the ocean is the largest carbon reservoir, such circulation changes were probably key in driving the variations in atmospheric CO2 concentrations observed in the ice-core record. However, we still lack a mechanistic understanding of the ocean’s role in regulating CO2 on these timescales. Here, we show that glacial ocean–sea ice numerical simulations with a single-basin general circulation model, forced solely by atmospheric cooling, can predict ocean circulation patterns associated with increased atmospheric carbon sequestration in the deep ocean. Under such conditions, Antarctic bottom water becomes more isolated from the sea surface as a result of two connected factors: reduced air–sea gas exchange under sea ice around Antarctica and weaker mixing with North Atlantic Deep Water due to a shallower interface between southern- and northern-sourced water masses. These physical changes alone are sufficient to explain ~40 ppm atmospheric CO2 drawdown—about half of the glacial–interglacial variation. Our results highlight that atmospheric cooling could have directly caused the reorganization of deep ocean water masses and, thus, glacial CO2 drawdown. This provides an important step towards a consistent picture of glacial climates. Article in Journal/Newspaper Antarc* Antarctic Antarctica ice core North Atlantic Deep Water North Atlantic Sea ice Natural Environment Research Council: NERC Open Research Archive Antarctic Nature Geoscience 12 12 1001 1005 |
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Natural Environment Research Council: NERC Open Research Archive |
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English |
description |
Palaeo-oceanographic reconstructions indicate that the distribution of global ocean water masses has undergone major glacial–interglacial rearrangements over the past ~2.5 million years. Given that the ocean is the largest carbon reservoir, such circulation changes were probably key in driving the variations in atmospheric CO2 concentrations observed in the ice-core record. However, we still lack a mechanistic understanding of the ocean’s role in regulating CO2 on these timescales. Here, we show that glacial ocean–sea ice numerical simulations with a single-basin general circulation model, forced solely by atmospheric cooling, can predict ocean circulation patterns associated with increased atmospheric carbon sequestration in the deep ocean. Under such conditions, Antarctic bottom water becomes more isolated from the sea surface as a result of two connected factors: reduced air–sea gas exchange under sea ice around Antarctica and weaker mixing with North Atlantic Deep Water due to a shallower interface between southern- and northern-sourced water masses. These physical changes alone are sufficient to explain ~40 ppm atmospheric CO2 drawdown—about half of the glacial–interglacial variation. Our results highlight that atmospheric cooling could have directly caused the reorganization of deep ocean water masses and, thus, glacial CO2 drawdown. This provides an important step towards a consistent picture of glacial climates. |
format |
Article in Journal/Newspaper |
author |
Marzocchi, Alice Jansen, Malte F. |
spellingShingle |
Marzocchi, Alice Jansen, Malte F. Global cooling linked to increased glacial carbon storage via changes in Antarctic sea ice |
author_facet |
Marzocchi, Alice Jansen, Malte F. |
author_sort |
Marzocchi, Alice |
title |
Global cooling linked to increased glacial carbon storage via changes in Antarctic sea ice |
title_short |
Global cooling linked to increased glacial carbon storage via changes in Antarctic sea ice |
title_full |
Global cooling linked to increased glacial carbon storage via changes in Antarctic sea ice |
title_fullStr |
Global cooling linked to increased glacial carbon storage via changes in Antarctic sea ice |
title_full_unstemmed |
Global cooling linked to increased glacial carbon storage via changes in Antarctic sea ice |
title_sort |
global cooling linked to increased glacial carbon storage via changes in antarctic sea ice |
publishDate |
2019 |
url |
http://nora.nerc.ac.uk/id/eprint/526522/ https://nora.nerc.ac.uk/id/eprint/526522/1/marzocchi_jansen1.pdf https://doi.org/10.1038/s41561-019-0466-8 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Antarctica ice core North Atlantic Deep Water North Atlantic Sea ice |
genre_facet |
Antarc* Antarctic Antarctica ice core North Atlantic Deep Water North Atlantic Sea ice |
op_relation |
https://nora.nerc.ac.uk/id/eprint/526522/1/marzocchi_jansen1.pdf Marzocchi, Alice orcid:0000-0002-3430-3574 Jansen, Malte F. 2019 Global cooling linked to increased glacial carbon storage via changes in Antarctic sea ice. Nature Geoscience, 12 (12). 1001-1005. https://doi.org/10.1038/s41561-019-0466-8 <https://doi.org/10.1038/s41561-019-0466-8> |
op_doi |
https://doi.org/10.1038/s41561-019-0466-8 |
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Nature Geoscience |
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12 |
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12 |
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1001 |
op_container_end_page |
1005 |
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1766156481247313920 |