Controls on Early Cretaceous South Atlantic Ocean circulation and carbon burial – a climate model–proxy synthesis
Black shale sediments from the Barremian to Aptian South Atlantic document the intense and widespread burial of marine organic carbon during the initial stages of seafloor spreading between Africa and South America. The enhanced sequestration of atmospheric CO 2 makes these young ocean basins potent...
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ftdoajarticles:oai:doaj.org/article:2e1411dc7d174e98937eda8b351315bb 2024-09-15T18:04:01+00:00 Controls on Early Cretaceous South Atlantic Ocean circulation and carbon burial – a climate model–proxy synthesis S. Steinig W. Dummann P. Hofmann M. Frank W. Park T. Wagner S. Flögel 2024-07-01T00:00:00Z https://doi.org/10.5194/cp-20-1537-2024 https://doaj.org/article/2e1411dc7d174e98937eda8b351315bb EN eng Copernicus Publications https://cp.copernicus.org/articles/20/1537/2024/cp-20-1537-2024.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-20-1537-2024 1814-9324 1814-9332 https://doaj.org/article/2e1411dc7d174e98937eda8b351315bb Climate of the Past, Vol 20, Pp 1537-1558 (2024) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2024 ftdoajarticles https://doi.org/10.5194/cp-20-1537-2024 2024-08-05T17:48:53Z Black shale sediments from the Barremian to Aptian South Atlantic document the intense and widespread burial of marine organic carbon during the initial stages of seafloor spreading between Africa and South America. The enhanced sequestration of atmospheric CO 2 makes these young ocean basins potential drivers of the Early Cretaceous carbon cycle and climate perturbations. The opening of marine gateways between initially restricted basins and related circulation and ventilation changes are a commonly invoked explanation for the transient formation and disappearance of these regional carbon sinks. However, large uncertainties in palaeogeographic reconstructions limit the interpretation of available palaeoceanographic data and prevent any robust model-based quantifications of the proposed circulation and carbon burial changes. Here, we present a new approach to assess the principal controls on the Early Cretaceous South Atlantic and Southern Ocean circulation changes under full consideration of the uncertainties in available boundary conditions. Specifically, we use a large ensemble of 36 climate model experiments to simulate the Barremian to Albian progressive opening of the Falkland Plateau and Georgia Basin gateways with different configurations of the proto-Drake Passage, the Walvis Ridge, and atmospheric CO 2 concentrations. The experiments are designed to complement available geochemical data across the regions and to test circulation scenarios derived from them. All simulations show increased evaporation and intermediate water formation at subtropical latitudes that drive a meridional overturning circulation whose vertical extent is determined by the sill depth of the Falkland Plateau. The densest water masses formed in the southern Angola Basin and potentially reached the deep Cape Basin as Walvis Ridge Overflow Water. Palaeogeographic uncertainties are as important as the lack of precise knowledge of atmospheric CO 2 levels for the simulated temperature and salinity spread in large parts of the South ... Article in Journal/Newspaper Drake Passage South Atlantic Ocean Southern Ocean Directory of Open Access Journals: DOAJ Articles |
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Directory of Open Access Journals: DOAJ Articles |
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language |
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topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
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Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 S. Steinig W. Dummann P. Hofmann M. Frank W. Park T. Wagner S. Flögel Controls on Early Cretaceous South Atlantic Ocean circulation and carbon burial – a climate model–proxy synthesis |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
Black shale sediments from the Barremian to Aptian South Atlantic document the intense and widespread burial of marine organic carbon during the initial stages of seafloor spreading between Africa and South America. The enhanced sequestration of atmospheric CO 2 makes these young ocean basins potential drivers of the Early Cretaceous carbon cycle and climate perturbations. The opening of marine gateways between initially restricted basins and related circulation and ventilation changes are a commonly invoked explanation for the transient formation and disappearance of these regional carbon sinks. However, large uncertainties in palaeogeographic reconstructions limit the interpretation of available palaeoceanographic data and prevent any robust model-based quantifications of the proposed circulation and carbon burial changes. Here, we present a new approach to assess the principal controls on the Early Cretaceous South Atlantic and Southern Ocean circulation changes under full consideration of the uncertainties in available boundary conditions. Specifically, we use a large ensemble of 36 climate model experiments to simulate the Barremian to Albian progressive opening of the Falkland Plateau and Georgia Basin gateways with different configurations of the proto-Drake Passage, the Walvis Ridge, and atmospheric CO 2 concentrations. The experiments are designed to complement available geochemical data across the regions and to test circulation scenarios derived from them. All simulations show increased evaporation and intermediate water formation at subtropical latitudes that drive a meridional overturning circulation whose vertical extent is determined by the sill depth of the Falkland Plateau. The densest water masses formed in the southern Angola Basin and potentially reached the deep Cape Basin as Walvis Ridge Overflow Water. Palaeogeographic uncertainties are as important as the lack of precise knowledge of atmospheric CO 2 levels for the simulated temperature and salinity spread in large parts of the South ... |
format |
Article in Journal/Newspaper |
author |
S. Steinig W. Dummann P. Hofmann M. Frank W. Park T. Wagner S. Flögel |
author_facet |
S. Steinig W. Dummann P. Hofmann M. Frank W. Park T. Wagner S. Flögel |
author_sort |
S. Steinig |
title |
Controls on Early Cretaceous South Atlantic Ocean circulation and carbon burial – a climate model–proxy synthesis |
title_short |
Controls on Early Cretaceous South Atlantic Ocean circulation and carbon burial – a climate model–proxy synthesis |
title_full |
Controls on Early Cretaceous South Atlantic Ocean circulation and carbon burial – a climate model–proxy synthesis |
title_fullStr |
Controls on Early Cretaceous South Atlantic Ocean circulation and carbon burial – a climate model–proxy synthesis |
title_full_unstemmed |
Controls on Early Cretaceous South Atlantic Ocean circulation and carbon burial – a climate model–proxy synthesis |
title_sort |
controls on early cretaceous south atlantic ocean circulation and carbon burial – a climate model–proxy synthesis |
publisher |
Copernicus Publications |
publishDate |
2024 |
url |
https://doi.org/10.5194/cp-20-1537-2024 https://doaj.org/article/2e1411dc7d174e98937eda8b351315bb |
genre |
Drake Passage South Atlantic Ocean Southern Ocean |
genre_facet |
Drake Passage South Atlantic Ocean Southern Ocean |
op_source |
Climate of the Past, Vol 20, Pp 1537-1558 (2024) |
op_relation |
https://cp.copernicus.org/articles/20/1537/2024/cp-20-1537-2024.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-20-1537-2024 1814-9324 1814-9332 https://doaj.org/article/2e1411dc7d174e98937eda8b351315bb |
op_doi |
https://doi.org/10.5194/cp-20-1537-2024 |
_version_ |
1810441497186664448 |