Radiocarbon Evidence for the Contribution of the Southern Indian Ocean to the Evolution of Atmospheric CO2 Over the Last 32,000 Years
It is widely assumed that the ventilation of the Southern Ocean played a crucial role in driving glacial-interglacial atmospheric CO2 levels. So far, however, ventilation records from the Indian sector of the Southern Ocean are widely missing. Here we present reconstructions of water residence times...
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ftsubggeo:oai:e-docs.geo-leo.de:11858/8796 2023-05-15T18:24:48+02:00 Radiocarbon Evidence for the Contribution of the Southern Indian Ocean to the Evolution of Atmospheric CO2 Over the Last 32,000 Years Ronge, Thomas A. Prange, Matthias Mollenhauer, Gesine Ellinghausen, Maret Kuhn, Gerhard Tiedemann, Ralf 2020 https://doi.org/10.1029/2019PA003733 http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/8796 eng eng doi:10.1029/2019PA003733 http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/8796 This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. CC-BY-NC ddc:551 radiocarbon ventilation Southern Ocean Younger Dryas carbon cycle Indian Ocean doc-type:article 2020 ftsubggeo https://doi.org/10.1029/2019PA003733 2022-11-09T06:51:38Z It is widely assumed that the ventilation of the Southern Ocean played a crucial role in driving glacial-interglacial atmospheric CO2 levels. So far, however, ventilation records from the Indian sector of the Southern Ocean are widely missing. Here we present reconstructions of water residence times (depicted as ΔΔ14C and Δδ13C) for the last 32,000 years on sediment records from the Kerguelen Plateau and the Conrad Rise (~570- to 2,500-m water depth), along with simulated changes in ocean stratification from a transient climate model experiment. Our data indicate that Circumpolar Deep Waters in the Indian Ocean were part of the glacial carbon pool. At our sites, close to or bathed by upwelling deep waters, we find two pulses of decreasing ΔΔ14C and δ13C values (~21–17 ka; ~15–12 ka). Both transient pulses precede a similar pattern in downstream intermediate waters in the tropical Indian Ocean as well as rising atmospheric CO2 values. These findings suggest that 14C-depleted, CO2-rich Circumpolar Deep Water from the Indian Ocean contributed to the rise in atmospheric CO2 during Heinrich Stadial 1 and also the Younger Dryas and that the southern Indian Ocean acted as a gateway for sequestered carbon to the atmosphere and tropical intermediate waters. Article in Journal/Newspaper Southern Ocean GEO-LEOe-docs (FID GEO) Southern Ocean Kerguelen Indian Conrad Rise ENVELOPE(41.000,41.000,-53.000,-53.000) Paleoceanography and Paleoclimatology 35 3 |
institution |
Open Polar |
collection |
GEO-LEOe-docs (FID GEO) |
op_collection_id |
ftsubggeo |
language |
English |
topic |
ddc:551 radiocarbon ventilation Southern Ocean Younger Dryas carbon cycle Indian Ocean |
spellingShingle |
ddc:551 radiocarbon ventilation Southern Ocean Younger Dryas carbon cycle Indian Ocean Ronge, Thomas A. Prange, Matthias Mollenhauer, Gesine Ellinghausen, Maret Kuhn, Gerhard Tiedemann, Ralf Radiocarbon Evidence for the Contribution of the Southern Indian Ocean to the Evolution of Atmospheric CO2 Over the Last 32,000 Years |
topic_facet |
ddc:551 radiocarbon ventilation Southern Ocean Younger Dryas carbon cycle Indian Ocean |
description |
It is widely assumed that the ventilation of the Southern Ocean played a crucial role in driving glacial-interglacial atmospheric CO2 levels. So far, however, ventilation records from the Indian sector of the Southern Ocean are widely missing. Here we present reconstructions of water residence times (depicted as ΔΔ14C and Δδ13C) for the last 32,000 years on sediment records from the Kerguelen Plateau and the Conrad Rise (~570- to 2,500-m water depth), along with simulated changes in ocean stratification from a transient climate model experiment. Our data indicate that Circumpolar Deep Waters in the Indian Ocean were part of the glacial carbon pool. At our sites, close to or bathed by upwelling deep waters, we find two pulses of decreasing ΔΔ14C and δ13C values (~21–17 ka; ~15–12 ka). Both transient pulses precede a similar pattern in downstream intermediate waters in the tropical Indian Ocean as well as rising atmospheric CO2 values. These findings suggest that 14C-depleted, CO2-rich Circumpolar Deep Water from the Indian Ocean contributed to the rise in atmospheric CO2 during Heinrich Stadial 1 and also the Younger Dryas and that the southern Indian Ocean acted as a gateway for sequestered carbon to the atmosphere and tropical intermediate waters. |
format |
Article in Journal/Newspaper |
author |
Ronge, Thomas A. Prange, Matthias Mollenhauer, Gesine Ellinghausen, Maret Kuhn, Gerhard Tiedemann, Ralf |
author_facet |
Ronge, Thomas A. Prange, Matthias Mollenhauer, Gesine Ellinghausen, Maret Kuhn, Gerhard Tiedemann, Ralf |
author_sort |
Ronge, Thomas A. |
title |
Radiocarbon Evidence for the Contribution of the Southern Indian Ocean to the Evolution of Atmospheric CO2 Over the Last 32,000 Years |
title_short |
Radiocarbon Evidence for the Contribution of the Southern Indian Ocean to the Evolution of Atmospheric CO2 Over the Last 32,000 Years |
title_full |
Radiocarbon Evidence for the Contribution of the Southern Indian Ocean to the Evolution of Atmospheric CO2 Over the Last 32,000 Years |
title_fullStr |
Radiocarbon Evidence for the Contribution of the Southern Indian Ocean to the Evolution of Atmospheric CO2 Over the Last 32,000 Years |
title_full_unstemmed |
Radiocarbon Evidence for the Contribution of the Southern Indian Ocean to the Evolution of Atmospheric CO2 Over the Last 32,000 Years |
title_sort |
radiocarbon evidence for the contribution of the southern indian ocean to the evolution of atmospheric co2 over the last 32,000 years |
publishDate |
2020 |
url |
https://doi.org/10.1029/2019PA003733 http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/8796 |
long_lat |
ENVELOPE(41.000,41.000,-53.000,-53.000) |
geographic |
Southern Ocean Kerguelen Indian Conrad Rise |
geographic_facet |
Southern Ocean Kerguelen Indian Conrad Rise |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
doi:10.1029/2019PA003733 http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/8796 |
op_rights |
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. |
op_rightsnorm |
CC-BY-NC |
op_doi |
https://doi.org/10.1029/2019PA003733 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
35 |
container_issue |
3 |
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1766205723930263552 |