Evolution of 231Pa and 230Th in overflow waters of the North Atlantic
15 pages, 11 figures.-- This work is distributed under the Creative Commons Attribution 4.0 License Many palaeoceanographic studies have sought to use the 231Pa=230Th ratio as a proxy for deep ocean circulation rates in the North Atlantic. As of yet, however, no study has fully assessed the concentr...
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Online Access: | http://hdl.handle.net/10261/176046 https://doi.org/10.5194/bg-15-7299-2018 |
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ftcsic:oai:digital.csic.es:10261/176046 2024-02-11T10:05:36+01:00 Evolution of 231Pa and 230Th in overflow waters of the North Atlantic Deng, Feifei Henderson, Gideon M. Castrillejo, Maxi Pérez, Fiz F. Steinfeldt, Reiner 2018 http://hdl.handle.net/10261/176046 https://doi.org/10.5194/bg-15-7299-2018 en eng European Geosciences Union Publisher's version https://doi.org/10.5194/bg-15-7299-2018 Sí Biogeosciences 15: 7299–7313, (2018) 1726-4170 http://hdl.handle.net/10261/176046 doi:10.5194/bg-15-7299-2018 1726-4189 open artículo http://purl.org/coar/resource_type/c_6501 2018 ftcsic https://doi.org/10.5194/bg-15-7299-2018 2024-01-16T10:35:59Z 15 pages, 11 figures.-- This work is distributed under the Creative Commons Attribution 4.0 License Many palaeoceanographic studies have sought to use the 231Pa=230Th ratio as a proxy for deep ocean circulation rates in the North Atlantic. As of yet, however, no study has fully assessed the concentration of, or controls on, 230Th and 231Pa in waters immediately following ventilation at the start of Atlantic meridional overturning. To that end, full water-column 231Pa and 230Th concentrations were measured along the GEOVIDE section, sampling a range of young North Atlantic deep waters. 230Th and 231Pa concentrations in the water column are lower than those observed further south in the Atlantic, ranging between 0.06 and 12.01 μBq kg1 and between 0.37 and 4.80 μBq kg1, respectively. Both 230Th and 231Pa profiles generally increase with water depth from surface to deep water, followed by decrease near the seafloor, with this feature most pronounced in the Labrador Sea (LA Sea) and Irminger Sea (IR Sea). Assessing this dataset using extended optimum multi-parameter (eOMP) analysis and CFC-based water mass age indicates that the low values of 230Th and 231Pa in water near the seafloor of the LA Sea and IR Sea are related to the young waters present in those regions. The importance of water age is confirmed for 230Th by a strong correlation between 230Th and water mass age (though this relationship with age is less clear for 231Pa and the 231Pa=230Th ratio). Scavenged 231Pa and 230Th were estimated and compared to their potential concentrations in the water column due to ingrowth. This calculation indicates that more 230Th is scavenged ( 80 %) than 231Pa ( 40 %), consistent with the relatively higher particle reactivity of 230Th. Enhanced scavenging for both nuclides is demonstrated near the seafloor in young overflow waters. Calculation of the meridional transport of 230Th and 231Pa with this new GEOVIDE dataset enables a complete budget for 230Th and 231Pa for the North Atlantic. Results suggest that net transport ... Article in Journal/Newspaper Labrador Sea North Atlantic Digital.CSIC (Spanish National Research Council) Irminger Sea ENVELOPE(-34.041,-34.041,63.054,63.054) Biogeosciences 15 23 7299 7313 |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
English |
description |
15 pages, 11 figures.-- This work is distributed under the Creative Commons Attribution 4.0 License Many palaeoceanographic studies have sought to use the 231Pa=230Th ratio as a proxy for deep ocean circulation rates in the North Atlantic. As of yet, however, no study has fully assessed the concentration of, or controls on, 230Th and 231Pa in waters immediately following ventilation at the start of Atlantic meridional overturning. To that end, full water-column 231Pa and 230Th concentrations were measured along the GEOVIDE section, sampling a range of young North Atlantic deep waters. 230Th and 231Pa concentrations in the water column are lower than those observed further south in the Atlantic, ranging between 0.06 and 12.01 μBq kg1 and between 0.37 and 4.80 μBq kg1, respectively. Both 230Th and 231Pa profiles generally increase with water depth from surface to deep water, followed by decrease near the seafloor, with this feature most pronounced in the Labrador Sea (LA Sea) and Irminger Sea (IR Sea). Assessing this dataset using extended optimum multi-parameter (eOMP) analysis and CFC-based water mass age indicates that the low values of 230Th and 231Pa in water near the seafloor of the LA Sea and IR Sea are related to the young waters present in those regions. The importance of water age is confirmed for 230Th by a strong correlation between 230Th and water mass age (though this relationship with age is less clear for 231Pa and the 231Pa=230Th ratio). Scavenged 231Pa and 230Th were estimated and compared to their potential concentrations in the water column due to ingrowth. This calculation indicates that more 230Th is scavenged ( 80 %) than 231Pa ( 40 %), consistent with the relatively higher particle reactivity of 230Th. Enhanced scavenging for both nuclides is demonstrated near the seafloor in young overflow waters. Calculation of the meridional transport of 230Th and 231Pa with this new GEOVIDE dataset enables a complete budget for 230Th and 231Pa for the North Atlantic. Results suggest that net transport ... |
format |
Article in Journal/Newspaper |
author |
Deng, Feifei Henderson, Gideon M. Castrillejo, Maxi Pérez, Fiz F. Steinfeldt, Reiner |
spellingShingle |
Deng, Feifei Henderson, Gideon M. Castrillejo, Maxi Pérez, Fiz F. Steinfeldt, Reiner Evolution of 231Pa and 230Th in overflow waters of the North Atlantic |
author_facet |
Deng, Feifei Henderson, Gideon M. Castrillejo, Maxi Pérez, Fiz F. Steinfeldt, Reiner |
author_sort |
Deng, Feifei |
title |
Evolution of 231Pa and 230Th in overflow waters of the North Atlantic |
title_short |
Evolution of 231Pa and 230Th in overflow waters of the North Atlantic |
title_full |
Evolution of 231Pa and 230Th in overflow waters of the North Atlantic |
title_fullStr |
Evolution of 231Pa and 230Th in overflow waters of the North Atlantic |
title_full_unstemmed |
Evolution of 231Pa and 230Th in overflow waters of the North Atlantic |
title_sort |
evolution of 231pa and 230th in overflow waters of the north atlantic |
publisher |
European Geosciences Union |
publishDate |
2018 |
url |
http://hdl.handle.net/10261/176046 https://doi.org/10.5194/bg-15-7299-2018 |
long_lat |
ENVELOPE(-34.041,-34.041,63.054,63.054) |
geographic |
Irminger Sea |
geographic_facet |
Irminger Sea |
genre |
Labrador Sea North Atlantic |
genre_facet |
Labrador Sea North Atlantic |
op_relation |
Publisher's version https://doi.org/10.5194/bg-15-7299-2018 Sí Biogeosciences 15: 7299–7313, (2018) 1726-4170 http://hdl.handle.net/10261/176046 doi:10.5194/bg-15-7299-2018 1726-4189 |
op_rights |
open |
op_doi |
https://doi.org/10.5194/bg-15-7299-2018 |
container_title |
Biogeosciences |
container_volume |
15 |
container_issue |
23 |
container_start_page |
7299 |
op_container_end_page |
7313 |
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1790602700488966144 |