Neodymium isotopic composition and concentration in the western North Atlantic Ocean: Results from the GEOTRACES GA02 section
The neodymium (Nd) isotopic composition of seawater is commonly used as a proxy to study past changes in the thermohaline circulation. The modern database for such reconstructions is however poor and the understanding of the underlying processes is incomplete. Here we present new observational data...
Published in: | Geochimica et Cosmochimica Acta |
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Online Access: | https://pure.uhi.ac.uk/en/publications/62d3b4bc-5d6c-4616-8963-d7394a78624b https://doi.org/10.1016/j.gca.2015.12.019 https://pureadmin.uhi.ac.uk/ws/files/2098017/Lambelet_et_al_GCA_2016_GA02_section.pdf http://www.sciencedirect.com/science/article/pii/S0016703715007139 |
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ftuhipublicatio:oai:pure.atira.dk:publications/62d3b4bc-5d6c-4616-8963-d7394a78624b 2024-09-15T18:17:15+00:00 Neodymium isotopic composition and concentration in the western North Atlantic Ocean: Results from the GEOTRACES GA02 section Lambelet, Myriam Van De Flierdt, Tina Crocket, Kirsty Rehkaemper, Mark Kreissig, Katharina Coles, Barry Rijkenberg, Micha Gerringa, Loes J.A. de Baar, Hein J.W. Steinfeldt, Reiner 2016-03-15 application/pdf https://pure.uhi.ac.uk/en/publications/62d3b4bc-5d6c-4616-8963-d7394a78624b https://doi.org/10.1016/j.gca.2015.12.019 https://pureadmin.uhi.ac.uk/ws/files/2098017/Lambelet_et_al_GCA_2016_GA02_section.pdf http://www.sciencedirect.com/science/article/pii/S0016703715007139 eng eng https://pure.uhi.ac.uk/en/publications/62d3b4bc-5d6c-4616-8963-d7394a78624b info:eu-repo/semantics/openAccess Lambelet , M , Van De Flierdt , T , Crocket , K , Rehkaemper , M , Kreissig , K , Coles , B , Rijkenberg , M , Gerringa , L J A , de Baar , H J W & Steinfeldt , R 2016 , ' Neodymium isotopic composition and concentration in the western North Atlantic Ocean : Results from the GEOTRACES GA02 section ' , Geochimica et Cosmochimica Acta , vol. 177 , pp. 1-29 . https://doi.org/10.1016/j.gca.2015.12.019 article 2016 ftuhipublicatio https://doi.org/10.1016/j.gca.2015.12.019 2024-07-29T23:37:15Z The neodymium (Nd) isotopic composition of seawater is commonly used as a proxy to study past changes in the thermohaline circulation. The modern database for such reconstructions is however poor and the understanding of the underlying processes is incomplete. Here we present new observational data for Nd isotopes and concentrations from twelve seawater depth profiles, which follow the flow path of North Atlantic Deep Water (NADW) from its formation region in the North Atlantic to the northern equatorial Atlantic. Samples were collected during two cruises constituting the northern part of the Dutch GEOTRACES transect GA02 in 2010. The results show that the different water masses in the subpolar North Atlantic Ocean, which ultimately constitute NADW, have the following Nd isotope characteristics: Upper Labrador Sea Water (ULSW), εNd = −14.2 ± 0.3; Labrador Sea Water (LSW), εNd = −13.7 ± 0.9; Northeast Atlantic Deep Water (NEADW), εNd = −12.5 ± 0.6; Northwest Atlantic Bottom Water (NWABW), εNd = −11.8 ± 1.4. In the subtropics, where these source water masses have mixed to form NADW, which is exported to the global ocean, upper-NADW is characterised by εNd values of −13.2 ± 1.0 (2sd) and lower-NADW exhibits values of εNd = −12.4 ± 0.4 (2sd). While both signatures overlap within error, the signature for lower-NADW is significantly more radiogenic than the traditionally used value for NADW (εNd = −13.5) due to the dominance of source waters from the Nordic Seas (NWABW and NEADW). Comparison between the concentration profiles and the corresponding Nd isotope profiles with other water mass properties such as salinity, silicate concentrations, neutral densities and chlorofluorocarbon (CFC) concentration provides novel insights into the geochemical cycle of Nd and reveals that different processes are necessary to account for the observed Nd characteristics in the subpolar and subtropical gyres and throughout the vertical water column. While our data set provides additional insights into the contribution of boundary ... Article in Journal/Newspaper Labrador Sea NADW Nordic Seas North Atlantic Deep Water North Atlantic Northeast Atlantic Northwest Atlantic University of the Highlands and Islands: Research Database of UHI Geochimica et Cosmochimica Acta 177 1 29 |
institution |
Open Polar |
collection |
University of the Highlands and Islands: Research Database of UHI |
op_collection_id |
ftuhipublicatio |
language |
English |
description |
The neodymium (Nd) isotopic composition of seawater is commonly used as a proxy to study past changes in the thermohaline circulation. The modern database for such reconstructions is however poor and the understanding of the underlying processes is incomplete. Here we present new observational data for Nd isotopes and concentrations from twelve seawater depth profiles, which follow the flow path of North Atlantic Deep Water (NADW) from its formation region in the North Atlantic to the northern equatorial Atlantic. Samples were collected during two cruises constituting the northern part of the Dutch GEOTRACES transect GA02 in 2010. The results show that the different water masses in the subpolar North Atlantic Ocean, which ultimately constitute NADW, have the following Nd isotope characteristics: Upper Labrador Sea Water (ULSW), εNd = −14.2 ± 0.3; Labrador Sea Water (LSW), εNd = −13.7 ± 0.9; Northeast Atlantic Deep Water (NEADW), εNd = −12.5 ± 0.6; Northwest Atlantic Bottom Water (NWABW), εNd = −11.8 ± 1.4. In the subtropics, where these source water masses have mixed to form NADW, which is exported to the global ocean, upper-NADW is characterised by εNd values of −13.2 ± 1.0 (2sd) and lower-NADW exhibits values of εNd = −12.4 ± 0.4 (2sd). While both signatures overlap within error, the signature for lower-NADW is significantly more radiogenic than the traditionally used value for NADW (εNd = −13.5) due to the dominance of source waters from the Nordic Seas (NWABW and NEADW). Comparison between the concentration profiles and the corresponding Nd isotope profiles with other water mass properties such as salinity, silicate concentrations, neutral densities and chlorofluorocarbon (CFC) concentration provides novel insights into the geochemical cycle of Nd and reveals that different processes are necessary to account for the observed Nd characteristics in the subpolar and subtropical gyres and throughout the vertical water column. While our data set provides additional insights into the contribution of boundary ... |
format |
Article in Journal/Newspaper |
author |
Lambelet, Myriam Van De Flierdt, Tina Crocket, Kirsty Rehkaemper, Mark Kreissig, Katharina Coles, Barry Rijkenberg, Micha Gerringa, Loes J.A. de Baar, Hein J.W. Steinfeldt, Reiner |
spellingShingle |
Lambelet, Myriam Van De Flierdt, Tina Crocket, Kirsty Rehkaemper, Mark Kreissig, Katharina Coles, Barry Rijkenberg, Micha Gerringa, Loes J.A. de Baar, Hein J.W. Steinfeldt, Reiner Neodymium isotopic composition and concentration in the western North Atlantic Ocean: Results from the GEOTRACES GA02 section |
author_facet |
Lambelet, Myriam Van De Flierdt, Tina Crocket, Kirsty Rehkaemper, Mark Kreissig, Katharina Coles, Barry Rijkenberg, Micha Gerringa, Loes J.A. de Baar, Hein J.W. Steinfeldt, Reiner |
author_sort |
Lambelet, Myriam |
title |
Neodymium isotopic composition and concentration in the western North Atlantic Ocean: Results from the GEOTRACES GA02 section |
title_short |
Neodymium isotopic composition and concentration in the western North Atlantic Ocean: Results from the GEOTRACES GA02 section |
title_full |
Neodymium isotopic composition and concentration in the western North Atlantic Ocean: Results from the GEOTRACES GA02 section |
title_fullStr |
Neodymium isotopic composition and concentration in the western North Atlantic Ocean: Results from the GEOTRACES GA02 section |
title_full_unstemmed |
Neodymium isotopic composition and concentration in the western North Atlantic Ocean: Results from the GEOTRACES GA02 section |
title_sort |
neodymium isotopic composition and concentration in the western north atlantic ocean: results from the geotraces ga02 section |
publishDate |
2016 |
url |
https://pure.uhi.ac.uk/en/publications/62d3b4bc-5d6c-4616-8963-d7394a78624b https://doi.org/10.1016/j.gca.2015.12.019 https://pureadmin.uhi.ac.uk/ws/files/2098017/Lambelet_et_al_GCA_2016_GA02_section.pdf http://www.sciencedirect.com/science/article/pii/S0016703715007139 |
genre |
Labrador Sea NADW Nordic Seas North Atlantic Deep Water North Atlantic Northeast Atlantic Northwest Atlantic |
genre_facet |
Labrador Sea NADW Nordic Seas North Atlantic Deep Water North Atlantic Northeast Atlantic Northwest Atlantic |
op_source |
Lambelet , M , Van De Flierdt , T , Crocket , K , Rehkaemper , M , Kreissig , K , Coles , B , Rijkenberg , M , Gerringa , L J A , de Baar , H J W & Steinfeldt , R 2016 , ' Neodymium isotopic composition and concentration in the western North Atlantic Ocean : Results from the GEOTRACES GA02 section ' , Geochimica et Cosmochimica Acta , vol. 177 , pp. 1-29 . https://doi.org/10.1016/j.gca.2015.12.019 |
op_relation |
https://pure.uhi.ac.uk/en/publications/62d3b4bc-5d6c-4616-8963-d7394a78624b |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.gca.2015.12.019 |
container_title |
Geochimica et Cosmochimica Acta |
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177 |
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1 |
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29 |
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1810455267125493760 |