Mid-depth South Atlantic Ocean circulation and chemical stratification during MIS-10 to 12: implications for atmospheric CO2
A detailed record of benthic foraminifera carbon isotopes from the intermediate-depth South East Atlantic margin shows little glacial-interglacial variability between MIS-12 to MIS-10, suggesting that Northern Atlantic deepwaters consistently penetrated to at least 30° S. Millennial-scale increases...
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ftcopernicus:oai:publications.copernicus.org:cp6315 2023-05-15T17:25:24+02:00 Mid-depth South Atlantic Ocean circulation and chemical stratification during MIS-10 to 12: implications for atmospheric CO2 Dickson, A. J. Leng, M. J. Maslin, M. A. 2018-09-27 application/pdf https://doi.org/10.5194/cp-4-333-2008 https://cp.copernicus.org/articles/4/333/2008/ eng eng doi:10.5194/cp-4-333-2008 https://cp.copernicus.org/articles/4/333/2008/ eISSN: 1814-9332 Text 2018 ftcopernicus https://doi.org/10.5194/cp-4-333-2008 2020-07-20T16:26:47Z A detailed record of benthic foraminifera carbon isotopes from the intermediate-depth South East Atlantic margin shows little glacial-interglacial variability between MIS-12 to MIS-10, suggesting that Northern Atlantic deepwaters consistently penetrated to at least 30° S. Millennial-scale increases in either the mass or flux of northern-sourced deepwaters over the core site occurred alongside reductions in Lower North Atlantic Deep Water recorded in North Atlantic sediment cores and show that the lower and intermediate limb of the Atlantic deepwater convective cell oscillated in anti-phase during previous glacial periods. In addition, a 500 yr resolution record of the Cape Basin intermediate-deep δ 13 C gradient shows that a reduction in deep Southern Ocean ventilation at the end of MIS-11 was consistent with a modelled CO 2 drawdown of ~21–30 ppm. Further increases in the Southern Ocean chemical divide during the transition into MIS-10 were completed before minimum CO 2 levels were reached, suggesting that other mechanisms such as alkalinity changes were responsible for the remaining ~45 ppm drawdown. Text North Atlantic Deep Water North Atlantic South Atlantic Ocean Southern Ocean Copernicus Publications: E-Journals Southern Ocean Climate of the Past 4 4 333 344 |
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Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
A detailed record of benthic foraminifera carbon isotopes from the intermediate-depth South East Atlantic margin shows little glacial-interglacial variability between MIS-12 to MIS-10, suggesting that Northern Atlantic deepwaters consistently penetrated to at least 30° S. Millennial-scale increases in either the mass or flux of northern-sourced deepwaters over the core site occurred alongside reductions in Lower North Atlantic Deep Water recorded in North Atlantic sediment cores and show that the lower and intermediate limb of the Atlantic deepwater convective cell oscillated in anti-phase during previous glacial periods. In addition, a 500 yr resolution record of the Cape Basin intermediate-deep δ 13 C gradient shows that a reduction in deep Southern Ocean ventilation at the end of MIS-11 was consistent with a modelled CO 2 drawdown of ~21–30 ppm. Further increases in the Southern Ocean chemical divide during the transition into MIS-10 were completed before minimum CO 2 levels were reached, suggesting that other mechanisms such as alkalinity changes were responsible for the remaining ~45 ppm drawdown. |
format |
Text |
author |
Dickson, A. J. Leng, M. J. Maslin, M. A. |
spellingShingle |
Dickson, A. J. Leng, M. J. Maslin, M. A. Mid-depth South Atlantic Ocean circulation and chemical stratification during MIS-10 to 12: implications for atmospheric CO2 |
author_facet |
Dickson, A. J. Leng, M. J. Maslin, M. A. |
author_sort |
Dickson, A. J. |
title |
Mid-depth South Atlantic Ocean circulation and chemical stratification during MIS-10 to 12: implications for atmospheric CO2 |
title_short |
Mid-depth South Atlantic Ocean circulation and chemical stratification during MIS-10 to 12: implications for atmospheric CO2 |
title_full |
Mid-depth South Atlantic Ocean circulation and chemical stratification during MIS-10 to 12: implications for atmospheric CO2 |
title_fullStr |
Mid-depth South Atlantic Ocean circulation and chemical stratification during MIS-10 to 12: implications for atmospheric CO2 |
title_full_unstemmed |
Mid-depth South Atlantic Ocean circulation and chemical stratification during MIS-10 to 12: implications for atmospheric CO2 |
title_sort |
mid-depth south atlantic ocean circulation and chemical stratification during mis-10 to 12: implications for atmospheric co2 |
publishDate |
2018 |
url |
https://doi.org/10.5194/cp-4-333-2008 https://cp.copernicus.org/articles/4/333/2008/ |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
North Atlantic Deep Water North Atlantic South Atlantic Ocean Southern Ocean |
genre_facet |
North Atlantic Deep Water North Atlantic South Atlantic Ocean Southern Ocean |
op_source |
eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-4-333-2008 https://cp.copernicus.org/articles/4/333/2008/ |
op_doi |
https://doi.org/10.5194/cp-4-333-2008 |
container_title |
Climate of the Past |
container_volume |
4 |
container_issue |
4 |
container_start_page |
333 |
op_container_end_page |
344 |
_version_ |
1766116826150862848 |