Evidence for late glacial oceanic carbon redistribution and discharge from the Pacific Southern Ocean
Southern Ocean deep-water circulation plays an important role in the global carbon cycle. On geological time-scales, upwelling along the Chilean continental margin likely contributed to the deglacial atmospheric carbon dioxide rise, but little quantitative evidence exists of carbon storage. Here, we...
| Published in: | Nature Communications |
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| Main Authors: | , , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
Springer Nature
2022
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| Subjects: | |
| Online Access: | https://epic.awi.de/id/eprint/57548/ https://epic.awi.de/id/eprint/57548/1/s41467-022-33753-4.pdf https://hdl.handle.net/10013/epic.13b99952-8b91-49df-991d-5cc893e9f662 |
| Summary: | Southern Ocean deep-water circulation plays an important role in the global carbon cycle. On geological time-scales, upwelling along the Chilean continental margin likely contributed to the deglacial atmospheric carbon dioxide rise, but little quantitative evidence exists of carbon storage. Here, we use a new X-ray Micro-Computer-Tomography method to assess foraminiferal test dissolution as proxy for paleo-carbonate ion concentrations [CO3^2−]. Our subantarctic Southeast Pacific sediment core depth transect shows significant deep-water [CO3^2−] variations during the Last Glacial Maximum and Deglaciation (10 – 22 ka BP). We provide evidence for an increase in [CO3^2−] during the early deglacial period (15-19 ka BP), followed by a ca. 40 µmol kg^-1 reduction in Lower Circumpolar Deepwater (CDW). This decreased Pacific to Atlantic export of low-carbon CDW contributed to significantly lowered carbon storage within the Southern Ocean, highlighting the importance of a dynamic Pacific–Southern Ocean deep-water reconfiguration for shaping late-glacial oceanic carbon storage, and subsequent deglacial oceanic-atmospheric CO2 transfer. |
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