Oceanic Cd/P ratio and nutrient utilization in the glacial Southern Ocean
During glacial periods, low atmospheric carbon dioxide concentration has been associated with increased oceanic carbon uptake, particularly in the southern oceans. The mechanism involved remains unclear. Because ocean productivity is strongly influenced by nutrient levels, palaeo-oceanographic proxi...
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Online Access: | https://doi.org/10.1038/35012507 https://ora.ox.ac.uk/objects/uuid:107a638b-9c7f-4d2b-8782-c09026d09494 |
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ftuloxford:oai:ora.ox.ac.uk:uuid:107a638b-9c7f-4d2b-8782-c09026d09494 2023-05-15T18:00:51+02:00 Oceanic Cd/P ratio and nutrient utilization in the glacial Southern Ocean Elderfield, H Rickaby, R 2016-07-28 https://doi.org/10.1038/35012507 https://ora.ox.ac.uk/objects/uuid:107a638b-9c7f-4d2b-8782-c09026d09494 eng eng doi:10.1038/35012507 https://ora.ox.ac.uk/objects/uuid:107a638b-9c7f-4d2b-8782-c09026d09494 https://doi.org/10.1038/35012507 info:eu-repo/semantics/embargoedAccess Journal article 2016 ftuloxford https://doi.org/10.1038/35012507 2022-06-28T20:06:05Z During glacial periods, low atmospheric carbon dioxide concentration has been associated with increased oceanic carbon uptake, particularly in the southern oceans. The mechanism involved remains unclear. Because ocean productivity is strongly influenced by nutrient levels, palaeo-oceanographic proxies have been applied to investigate nutrient utilization in surface water across glacial transitions. Here we show that present-day cadmium and phosphorus concentrations in the global oceans can be explained by a chemical fractionation during particle formation, whereby uptake of cadmium occurs in preference to uptake of phosphorus. This allows the reconstruction of past surface water phosphate concentrations from the cadmium/calcium ratio of planktonic foraminifera. Results from the Last Glacial Maximum show similar phosphate utilization in the subantarctic to that of today, but much smaller utilization in the polar Southern Ocean, in a model that is consistent with the expansion of glacial sea ice and which can reconcile all proxy records of polar nutrient utilization. By restricting communication between the ocean and atmosphere, sea ice expansion also provides a mechanism for reduced CO2 release by the Southern Ocean and lower glacial atmospheric CO2. Article in Journal/Newspaper Planktonic foraminifera Sea ice Southern Ocean ORA - Oxford University Research Archive Southern Ocean Nature 405 6784 305 310 |
institution |
Open Polar |
collection |
ORA - Oxford University Research Archive |
op_collection_id |
ftuloxford |
language |
English |
description |
During glacial periods, low atmospheric carbon dioxide concentration has been associated with increased oceanic carbon uptake, particularly in the southern oceans. The mechanism involved remains unclear. Because ocean productivity is strongly influenced by nutrient levels, palaeo-oceanographic proxies have been applied to investigate nutrient utilization in surface water across glacial transitions. Here we show that present-day cadmium and phosphorus concentrations in the global oceans can be explained by a chemical fractionation during particle formation, whereby uptake of cadmium occurs in preference to uptake of phosphorus. This allows the reconstruction of past surface water phosphate concentrations from the cadmium/calcium ratio of planktonic foraminifera. Results from the Last Glacial Maximum show similar phosphate utilization in the subantarctic to that of today, but much smaller utilization in the polar Southern Ocean, in a model that is consistent with the expansion of glacial sea ice and which can reconcile all proxy records of polar nutrient utilization. By restricting communication between the ocean and atmosphere, sea ice expansion also provides a mechanism for reduced CO2 release by the Southern Ocean and lower glacial atmospheric CO2. |
format |
Article in Journal/Newspaper |
author |
Elderfield, H Rickaby, R |
spellingShingle |
Elderfield, H Rickaby, R Oceanic Cd/P ratio and nutrient utilization in the glacial Southern Ocean |
author_facet |
Elderfield, H Rickaby, R |
author_sort |
Elderfield, H |
title |
Oceanic Cd/P ratio and nutrient utilization in the glacial Southern Ocean |
title_short |
Oceanic Cd/P ratio and nutrient utilization in the glacial Southern Ocean |
title_full |
Oceanic Cd/P ratio and nutrient utilization in the glacial Southern Ocean |
title_fullStr |
Oceanic Cd/P ratio and nutrient utilization in the glacial Southern Ocean |
title_full_unstemmed |
Oceanic Cd/P ratio and nutrient utilization in the glacial Southern Ocean |
title_sort |
oceanic cd/p ratio and nutrient utilization in the glacial southern ocean |
publishDate |
2016 |
url |
https://doi.org/10.1038/35012507 https://ora.ox.ac.uk/objects/uuid:107a638b-9c7f-4d2b-8782-c09026d09494 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Planktonic foraminifera Sea ice Southern Ocean |
genre_facet |
Planktonic foraminifera Sea ice Southern Ocean |
op_relation |
doi:10.1038/35012507 https://ora.ox.ac.uk/objects/uuid:107a638b-9c7f-4d2b-8782-c09026d09494 https://doi.org/10.1038/35012507 |
op_rights |
info:eu-repo/semantics/embargoedAccess |
op_doi |
https://doi.org/10.1038/35012507 |
container_title |
Nature |
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405 |
container_issue |
6784 |
container_start_page |
305 |
op_container_end_page |
310 |
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1766170124182618112 |