Sea-ice control on deglacial lower cell circulation changes recorded by Drake Passage deep-sea corals
The sequence of deep ocean circulation changes between the Last Glacial Maximum and the Holocene provides important insights for understanding deglacial climate change and the role of the deep ocean in the global carbon cycle. Although it is known that significant amounts of carbon were sequestered...
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ftimperialcol:oai:spiral.imperial.ac.uk:10044/1/79644 2023-05-15T13:53:11+02:00 Sea-ice control on deglacial lower cell circulation changes recorded by Drake Passage deep-sea corals Wilson, DJ Struve, T Van de Flierdt, T Chen, T Li, T Burke, A Robinson, LF Natural Environment Research Council (NERC) Commission of the European Communities The Leverhulme Trust 2020-06-05 http://hdl.handle.net/10044/1/79644 unknown Elsevier Earth and Planetary Science Letters 0012-821X http://hdl.handle.net/10044/1/79644 NE/F016751/1 PIRG03-GA-2008-230828 RPG-398 NE/N001141/1 10000-01-01 02 Physical Sciences 04 Earth Sciences Geochemistry & Geophysics Journal Article 2020 ftimperialcol 2020-06-11T22:38:27Z The sequence of deep ocean circulation changes between the Last Glacial Maximum and the Holocene provides important insights for understanding deglacial climate change and the role of the deep ocean in the global carbon cycle. Although it is known that significant amounts of carbon were sequestered in a deep overturning cell during glacial periods and released during deglaciation, the driving mechanisms for these changes remain unresolved. Southern Ocean sea-ice has recently been proposed to play a critical role in setting the global deep ocean stratification and circulation, and hence carbon storage, but testing such conceptual and modelling studies requires data constraining past circulation changes. To this end, we present the first deglacial dataset of neodymium (Nd) isotopes measured on absolute-dated deep-sea corals from modern Lower Circumpolar Deep Water depths in the Drake Passage. Our record demonstrates deglacial variability of 2.5 εNd units, with radiogenic values of up to εNd = -5.9 during the Last Glacial Maximum providing evidence for a stratified glacial circulation mode with restricted incorporation of Nd from North Atlantic Deep Water in the lower cell. During the deglaciation, a renewed Atlantic influence in the deep Southern Ocean is recorded early in Heinrich Stadial 1, coincident with Antarctic sea-ice retreat, and is followed by a brief return to more Pacific-like values during the Antarctic Cold Reversal. These changes demonstrate a strong influence of Southern Ocean processes in setting deep ocean circulation and support the proposed sea-ice control on deep ocean structure. Furthermore, by constraining the Nd isotopic composition of Lower Circumpolar Deep Water in the Southern Ocean, our new data is important for interpreting deglacial circulation changes in other ocean basins and supports a spatially asynchronous return of North Atlantic Deep Water to the deep southeast and southwest Atlantic Ocean. Article in Journal/Newspaper Antarc* Antarctic Drake Passage North Atlantic Deep Water North Atlantic Sea ice Southern Ocean Imperial College London: Spiral Antarctic Drake Passage Pacific Southern Ocean The Antarctic |
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Open Polar |
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Imperial College London: Spiral |
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unknown |
topic |
02 Physical Sciences 04 Earth Sciences Geochemistry & Geophysics |
spellingShingle |
02 Physical Sciences 04 Earth Sciences Geochemistry & Geophysics Wilson, DJ Struve, T Van de Flierdt, T Chen, T Li, T Burke, A Robinson, LF Sea-ice control on deglacial lower cell circulation changes recorded by Drake Passage deep-sea corals |
topic_facet |
02 Physical Sciences 04 Earth Sciences Geochemistry & Geophysics |
description |
The sequence of deep ocean circulation changes between the Last Glacial Maximum and the Holocene provides important insights for understanding deglacial climate change and the role of the deep ocean in the global carbon cycle. Although it is known that significant amounts of carbon were sequestered in a deep overturning cell during glacial periods and released during deglaciation, the driving mechanisms for these changes remain unresolved. Southern Ocean sea-ice has recently been proposed to play a critical role in setting the global deep ocean stratification and circulation, and hence carbon storage, but testing such conceptual and modelling studies requires data constraining past circulation changes. To this end, we present the first deglacial dataset of neodymium (Nd) isotopes measured on absolute-dated deep-sea corals from modern Lower Circumpolar Deep Water depths in the Drake Passage. Our record demonstrates deglacial variability of 2.5 εNd units, with radiogenic values of up to εNd = -5.9 during the Last Glacial Maximum providing evidence for a stratified glacial circulation mode with restricted incorporation of Nd from North Atlantic Deep Water in the lower cell. During the deglaciation, a renewed Atlantic influence in the deep Southern Ocean is recorded early in Heinrich Stadial 1, coincident with Antarctic sea-ice retreat, and is followed by a brief return to more Pacific-like values during the Antarctic Cold Reversal. These changes demonstrate a strong influence of Southern Ocean processes in setting deep ocean circulation and support the proposed sea-ice control on deep ocean structure. Furthermore, by constraining the Nd isotopic composition of Lower Circumpolar Deep Water in the Southern Ocean, our new data is important for interpreting deglacial circulation changes in other ocean basins and supports a spatially asynchronous return of North Atlantic Deep Water to the deep southeast and southwest Atlantic Ocean. |
author2 |
Natural Environment Research Council (NERC) Commission of the European Communities The Leverhulme Trust |
format |
Article in Journal/Newspaper |
author |
Wilson, DJ Struve, T Van de Flierdt, T Chen, T Li, T Burke, A Robinson, LF |
author_facet |
Wilson, DJ Struve, T Van de Flierdt, T Chen, T Li, T Burke, A Robinson, LF |
author_sort |
Wilson, DJ |
title |
Sea-ice control on deglacial lower cell circulation changes recorded by Drake Passage deep-sea corals |
title_short |
Sea-ice control on deglacial lower cell circulation changes recorded by Drake Passage deep-sea corals |
title_full |
Sea-ice control on deglacial lower cell circulation changes recorded by Drake Passage deep-sea corals |
title_fullStr |
Sea-ice control on deglacial lower cell circulation changes recorded by Drake Passage deep-sea corals |
title_full_unstemmed |
Sea-ice control on deglacial lower cell circulation changes recorded by Drake Passage deep-sea corals |
title_sort |
sea-ice control on deglacial lower cell circulation changes recorded by drake passage deep-sea corals |
publisher |
Elsevier |
publishDate |
2020 |
url |
http://hdl.handle.net/10044/1/79644 |
geographic |
Antarctic Drake Passage Pacific Southern Ocean The Antarctic |
geographic_facet |
Antarctic Drake Passage Pacific Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Drake Passage North Atlantic Deep Water North Atlantic Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Drake Passage North Atlantic Deep Water North Atlantic Sea ice Southern Ocean |
op_relation |
Earth and Planetary Science Letters 0012-821X http://hdl.handle.net/10044/1/79644 NE/F016751/1 PIRG03-GA-2008-230828 RPG-398 NE/N001141/1 |
op_rights |
10000-01-01 |
_version_ |
1766258161529913344 |