Sediment Release in the Benguela Upwelling System Dominates Trace Metal Input to the Shelf and Eastern South Atlantic Ocean
Upwelling of subsurface waters injects macronutrients (fixed N, P, and Si) and micronutrient trace metals (TMs) into surface waters supporting elevated primary production in Eastern Boundary Upwelling Regions. The eastern South Atlantic features a highly productive shelf sea transitioning to a low p...
Published in: | Global Biogeochemical Cycles |
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2022
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Online Access: | https://doi.org/10.1029/2022GB007466 http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/10435 |
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ftsubggeo:oai:e-docs.geo-leo.de:11858/10435 2023-05-15T18:20:55+02:00 Sediment Release in the Benguela Upwelling System Dominates Trace Metal Input to the Shelf and Eastern South Atlantic Ocean Liu, Te Krisch, Stephan Xie, Ruifang C. Hopwood, Mark J. Dengler, Marcus Achterberg, Eric P. Krisch, Stephan; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany Hopwood, Mark J.; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany Dengler, Marcus; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany Achterberg, Eric P.; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany 2022-09-25 https://doi.org/10.1029/2022GB007466 http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/10435 eng eng doi:10.1029/2022GB007466 http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/10435 This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made. CC-BY-NC-ND ddc:551 dissolved trace metals Benguela Upwelling Systems fluxes Eastern Boundary Upwelling Systems Regions doc-type:article 2022 ftsubggeo https://doi.org/10.1029/2022GB007466 2023-01-22T23:12:04Z Upwelling of subsurface waters injects macronutrients (fixed N, P, and Si) and micronutrient trace metals (TMs) into surface waters supporting elevated primary production in Eastern Boundary Upwelling Regions. The eastern South Atlantic features a highly productive shelf sea transitioning to a low productivity N‐Fe (co)limited open ocean. Whilst a gradient in most TM concentrations is expected in any off‐shelf transect, the factors controlling the magnitude of cross‐shelf TM fluxes are poorly constrained. Here, we present dissolved TM concentrations of Fe, Co, Mn, Cd, Ni, and Cu within the Benguela Upwelling System from the coastal section of the GEOTRACES GA08 cruise. Elevated dissolved Fe, Co, Mn, Cd, Ni, Cu and macronutrient concentrations were observed near shelf sediments. Benthic sources supplied 2.22 ± 0.99 μmol Fe m−2 day−1, 0.05 ± 0.03 μmol Co m−2 day−1, 0.28 ± 0.11 μmol Mn m−2 day−1 and were found to be the dominant source to shallow shelf waters compared to atmospheric depositions. Similarly, off‐shelf transfer was a more important source of TMs to the eastern South Atlantic Ocean compared to atmospheric deposition. Assessment of surface (shelf, upper 200 m) and subsurface (shelf edge, 200–500 m) fluxes of Fe and Co indicated TM fluxes from subsurface were 2–5 times larger than those from surface into the eastern South Atlantic Ocean. Under future conditions of increasing ocean deoxygenation, these fluxes may increase further, potentially contributing to a shift toward more extensive regional limitation of primary production by fixed N availability. Key Points: Shelf sediments release redox‐sensitive trace metals (TMs) to overlying oxygen‐depleted waters in the Benguela Upwelling System. Sediment‐derived TMs are upwelled and laterally transported constituting a major source to shelf waters and to the eastern South Atlantic. Subsurface fluxes of dissolved Fe and Co from the shelf edge play an important role in supplying Fe and Co to the eastern South Atlantic. China Scholarship Council, CSC ... Article in Journal/Newspaper South Atlantic Ocean GEO-LEOe-docs (FID GEO) Global Biogeochemical Cycles 36 9 |
institution |
Open Polar |
collection |
GEO-LEOe-docs (FID GEO) |
op_collection_id |
ftsubggeo |
language |
English |
topic |
ddc:551 dissolved trace metals Benguela Upwelling Systems fluxes Eastern Boundary Upwelling Systems Regions |
spellingShingle |
ddc:551 dissolved trace metals Benguela Upwelling Systems fluxes Eastern Boundary Upwelling Systems Regions Liu, Te Krisch, Stephan Xie, Ruifang C. Hopwood, Mark J. Dengler, Marcus Achterberg, Eric P. Krisch, Stephan; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany Hopwood, Mark J.; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany Dengler, Marcus; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany Achterberg, Eric P.; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany Sediment Release in the Benguela Upwelling System Dominates Trace Metal Input to the Shelf and Eastern South Atlantic Ocean |
topic_facet |
ddc:551 dissolved trace metals Benguela Upwelling Systems fluxes Eastern Boundary Upwelling Systems Regions |
description |
Upwelling of subsurface waters injects macronutrients (fixed N, P, and Si) and micronutrient trace metals (TMs) into surface waters supporting elevated primary production in Eastern Boundary Upwelling Regions. The eastern South Atlantic features a highly productive shelf sea transitioning to a low productivity N‐Fe (co)limited open ocean. Whilst a gradient in most TM concentrations is expected in any off‐shelf transect, the factors controlling the magnitude of cross‐shelf TM fluxes are poorly constrained. Here, we present dissolved TM concentrations of Fe, Co, Mn, Cd, Ni, and Cu within the Benguela Upwelling System from the coastal section of the GEOTRACES GA08 cruise. Elevated dissolved Fe, Co, Mn, Cd, Ni, Cu and macronutrient concentrations were observed near shelf sediments. Benthic sources supplied 2.22 ± 0.99 μmol Fe m−2 day−1, 0.05 ± 0.03 μmol Co m−2 day−1, 0.28 ± 0.11 μmol Mn m−2 day−1 and were found to be the dominant source to shallow shelf waters compared to atmospheric depositions. Similarly, off‐shelf transfer was a more important source of TMs to the eastern South Atlantic Ocean compared to atmospheric deposition. Assessment of surface (shelf, upper 200 m) and subsurface (shelf edge, 200–500 m) fluxes of Fe and Co indicated TM fluxes from subsurface were 2–5 times larger than those from surface into the eastern South Atlantic Ocean. Under future conditions of increasing ocean deoxygenation, these fluxes may increase further, potentially contributing to a shift toward more extensive regional limitation of primary production by fixed N availability. Key Points: Shelf sediments release redox‐sensitive trace metals (TMs) to overlying oxygen‐depleted waters in the Benguela Upwelling System. Sediment‐derived TMs are upwelled and laterally transported constituting a major source to shelf waters and to the eastern South Atlantic. Subsurface fluxes of dissolved Fe and Co from the shelf edge play an important role in supplying Fe and Co to the eastern South Atlantic. China Scholarship Council, CSC ... |
format |
Article in Journal/Newspaper |
author |
Liu, Te Krisch, Stephan Xie, Ruifang C. Hopwood, Mark J. Dengler, Marcus Achterberg, Eric P. Krisch, Stephan; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany Hopwood, Mark J.; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany Dengler, Marcus; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany Achterberg, Eric P.; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany |
author_facet |
Liu, Te Krisch, Stephan Xie, Ruifang C. Hopwood, Mark J. Dengler, Marcus Achterberg, Eric P. Krisch, Stephan; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany Hopwood, Mark J.; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany Dengler, Marcus; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany Achterberg, Eric P.; 1 GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany |
author_sort |
Liu, Te |
title |
Sediment Release in the Benguela Upwelling System Dominates Trace Metal Input to the Shelf and Eastern South Atlantic Ocean |
title_short |
Sediment Release in the Benguela Upwelling System Dominates Trace Metal Input to the Shelf and Eastern South Atlantic Ocean |
title_full |
Sediment Release in the Benguela Upwelling System Dominates Trace Metal Input to the Shelf and Eastern South Atlantic Ocean |
title_fullStr |
Sediment Release in the Benguela Upwelling System Dominates Trace Metal Input to the Shelf and Eastern South Atlantic Ocean |
title_full_unstemmed |
Sediment Release in the Benguela Upwelling System Dominates Trace Metal Input to the Shelf and Eastern South Atlantic Ocean |
title_sort |
sediment release in the benguela upwelling system dominates trace metal input to the shelf and eastern south atlantic ocean |
publishDate |
2022 |
url |
https://doi.org/10.1029/2022GB007466 http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/10435 |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_relation |
doi:10.1029/2022GB007466 http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/10435 |
op_rights |
This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made. |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.1029/2022GB007466 |
container_title |
Global Biogeochemical Cycles |
container_volume |
36 |
container_issue |
9 |
_version_ |
1766199783818526720 |