The export flux of particulate organic carbon derived from 210Po/210Pb disequilibria along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise
The disequilibrium between 210Po activity and 210Pb activity in seawater samples was determined along the GEOTRACES GA01 transect in the North Atlantic during the GEOVIDE cruise (May–June 2014). A steady-state model was used to quantify vertical export of particulate 210Po. Vertical advection was in...
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ftethz:oai:www.research-collection.ethz.ch:20.500.11850/322742 2023-08-20T04:06:59+02:00 The export flux of particulate organic carbon derived from 210Po/210Pb disequilibria along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise Tang, Yi Lemaitre, Nolwenn Castrillejo, Maxi Roca-Marti, Montserrat Masqué, Pere Stewart, Gillian 2019 application/application/pdf https://hdl.handle.net/20.500.11850/322742 https://doi.org/10.3929/ethz-b-000322742 en eng Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-16-309-2019 info:eu-repo/semantics/altIdentifier/wos/000456710800001 http://hdl.handle.net/20.500.11850/322742 doi:10.3929/ethz-b-000322742 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International Biogeosciences, 16 (2) info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2019 ftethz https://doi.org/20.500.11850/32274210.3929/ethz-b-00032274210.5194/bg-16-309-2019 2023-07-30T23:49:54Z The disequilibrium between 210Po activity and 210Pb activity in seawater samples was determined along the GEOTRACES GA01 transect in the North Atlantic during the GEOVIDE cruise (May–June 2014). A steady-state model was used to quantify vertical export of particulate 210Po. Vertical advection was incorporated into one version of the model using time-averaged vertical velocity, which had substantial variance. This resulted in large uncertainties for the 210Po export flux in this model, suggesting that those calculations of 210Po export fluxes should be used with great care. Despite the large uncertainties, there is no question that the deficits of 210Po in the Iberian Basin and at the Greenland Shelf have been strongly affected by vertical advection. Using the export flux of 210Po and the particulate organic carbon (POC) to 210Po ratio of total (> 1 µm) particles, we determined the POC export fluxes along the transect. Both the magnitude and efficiency of the estimated POC export flux from the surface ocean varied spatially within our study region. Export fluxes of POC ranged from negligible to 10 mmol C m−2 d−1, with enhanced POC export in the Labrador Sea. The cruise track was characterized by overall low POC export relative to net primary production (export efficiency < 1 %–15 %), but relatively high export efficiencies were seen in the basins where diatoms dominated the phytoplankton community. The particularly low export efficiencies in the Iberian Basin, on the other hand, were explained by the dominance of smaller phytoplankton, such as cyanobacteria or coccolithophores. POC fluxes estimated from the 210Po∕210Pb and 234Th∕238U disequilibria agreed within a factor of 3 along the transect, with higher POC estimates generally derived from 234Th. The differences were attributed to integration timescales and the history of bloom events. ISSN:1726-4170 ISSN:1726-4170 Article in Journal/Newspaper Greenland Labrador Sea North Atlantic ETH Zürich Research Collection Greenland |
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Open Polar |
collection |
ETH Zürich Research Collection |
op_collection_id |
ftethz |
language |
English |
description |
The disequilibrium between 210Po activity and 210Pb activity in seawater samples was determined along the GEOTRACES GA01 transect in the North Atlantic during the GEOVIDE cruise (May–June 2014). A steady-state model was used to quantify vertical export of particulate 210Po. Vertical advection was incorporated into one version of the model using time-averaged vertical velocity, which had substantial variance. This resulted in large uncertainties for the 210Po export flux in this model, suggesting that those calculations of 210Po export fluxes should be used with great care. Despite the large uncertainties, there is no question that the deficits of 210Po in the Iberian Basin and at the Greenland Shelf have been strongly affected by vertical advection. Using the export flux of 210Po and the particulate organic carbon (POC) to 210Po ratio of total (> 1 µm) particles, we determined the POC export fluxes along the transect. Both the magnitude and efficiency of the estimated POC export flux from the surface ocean varied spatially within our study region. Export fluxes of POC ranged from negligible to 10 mmol C m−2 d−1, with enhanced POC export in the Labrador Sea. The cruise track was characterized by overall low POC export relative to net primary production (export efficiency < 1 %–15 %), but relatively high export efficiencies were seen in the basins where diatoms dominated the phytoplankton community. The particularly low export efficiencies in the Iberian Basin, on the other hand, were explained by the dominance of smaller phytoplankton, such as cyanobacteria or coccolithophores. POC fluxes estimated from the 210Po∕210Pb and 234Th∕238U disequilibria agreed within a factor of 3 along the transect, with higher POC estimates generally derived from 234Th. The differences were attributed to integration timescales and the history of bloom events. ISSN:1726-4170 ISSN:1726-4170 |
format |
Article in Journal/Newspaper |
author |
Tang, Yi Lemaitre, Nolwenn Castrillejo, Maxi Roca-Marti, Montserrat Masqué, Pere Stewart, Gillian |
spellingShingle |
Tang, Yi Lemaitre, Nolwenn Castrillejo, Maxi Roca-Marti, Montserrat Masqué, Pere Stewart, Gillian The export flux of particulate organic carbon derived from 210Po/210Pb disequilibria along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise |
author_facet |
Tang, Yi Lemaitre, Nolwenn Castrillejo, Maxi Roca-Marti, Montserrat Masqué, Pere Stewart, Gillian |
author_sort |
Tang, Yi |
title |
The export flux of particulate organic carbon derived from 210Po/210Pb disequilibria along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise |
title_short |
The export flux of particulate organic carbon derived from 210Po/210Pb disequilibria along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise |
title_full |
The export flux of particulate organic carbon derived from 210Po/210Pb disequilibria along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise |
title_fullStr |
The export flux of particulate organic carbon derived from 210Po/210Pb disequilibria along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise |
title_full_unstemmed |
The export flux of particulate organic carbon derived from 210Po/210Pb disequilibria along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise |
title_sort |
export flux of particulate organic carbon derived from 210po/210pb disequilibria along the north atlantic geotraces ga01 transect: geovide cruise |
publisher |
Copernicus |
publishDate |
2019 |
url |
https://hdl.handle.net/20.500.11850/322742 https://doi.org/10.3929/ethz-b-000322742 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Labrador Sea North Atlantic |
genre_facet |
Greenland Labrador Sea North Atlantic |
op_source |
Biogeosciences, 16 (2) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-16-309-2019 info:eu-repo/semantics/altIdentifier/wos/000456710800001 http://hdl.handle.net/20.500.11850/322742 doi:10.3929/ethz-b-000322742 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International |
op_doi |
https://doi.org/20.500.11850/32274210.3929/ethz-b-00032274210.5194/bg-16-309-2019 |
_version_ |
1774718365925900288 |