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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Edith Cowan University, Research Online, Perth, Western Australia
2019
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Online Access: | https://ro.ecu.edu.au/ecuworkspost2013/5819 https://doi.org/10.5194/bg-16-309-2019 https://ro.ecu.edu.au/context/ecuworkspost2013/article/6824/viewcontent/bg_16_309_2019.pdf |
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ftedithcowan:oai:ro.ecu.edu.au:ecuworkspost2013-6824 2023-06-11T04:12:22+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-Martí, Montserrat Masqué, Pere Stewart, Gillian 2019-01-01T08:00:00Z application/pdf https://ro.ecu.edu.au/ecuworkspost2013/5819 https://doi.org/10.5194/bg-16-309-2019 https://ro.ecu.edu.au/context/ecuworkspost2013/article/6824/viewcontent/bg_16_309_2019.pdf unknown Edith Cowan University, Research Online, Perth, Western Australia https://ro.ecu.edu.au/ecuworkspost2013/5819 doi:10.5194/bg-16-309-2019 https://ro.ecu.edu.au/context/ecuworkspost2013/article/6824/viewcontent/bg_16_309_2019.pdf http://creativecommons.org/licenses/by/4.0/ Research outputs 2014 to 2021 Bacillariophyta Cyanobacteria Haptophyceae Vindula arsine Chemistry Life Sciences text 2019 ftedithcowan https://doi.org/10.5194/bg-16-309-2019 2023-05-06T22:51:02Z 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 (>1μm) 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 10mmolCm-2d-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 210Po210Pb and 234Th238U 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. © 2019 Author(s). Text Greenland Labrador Sea North Atlantic Edith Cowan University (ECU, Australia): Research Online Greenland Biogeosciences 16 2 309 327 |
institution |
Open Polar |
collection |
Edith Cowan University (ECU, Australia): Research Online |
op_collection_id |
ftedithcowan |
language |
unknown |
topic |
Bacillariophyta Cyanobacteria Haptophyceae Vindula arsine Chemistry Life Sciences |
spellingShingle |
Bacillariophyta Cyanobacteria Haptophyceae Vindula arsine Chemistry Life Sciences Tang, Yi Lemaitre, Nolwenn Castrillejo, Maxi Roca-Martí, 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 |
topic_facet |
Bacillariophyta Cyanobacteria Haptophyceae Vindula arsine Chemistry Life Sciences |
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 (>1μm) 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 10mmolCm-2d-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 210Po210Pb and 234Th238U 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. © 2019 Author(s). |
format |
Text |
author |
Tang, Yi Lemaitre, Nolwenn Castrillejo, Maxi Roca-Martí, Montserrat Masqué, Pere Stewart, Gillian |
author_facet |
Tang, Yi Lemaitre, Nolwenn Castrillejo, Maxi Roca-Martí, 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 |
Edith Cowan University, Research Online, Perth, Western Australia |
publishDate |
2019 |
url |
https://ro.ecu.edu.au/ecuworkspost2013/5819 https://doi.org/10.5194/bg-16-309-2019 https://ro.ecu.edu.au/context/ecuworkspost2013/article/6824/viewcontent/bg_16_309_2019.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Labrador Sea North Atlantic |
genre_facet |
Greenland Labrador Sea North Atlantic |
op_source |
Research outputs 2014 to 2021 |
op_relation |
https://ro.ecu.edu.au/ecuworkspost2013/5819 doi:10.5194/bg-16-309-2019 https://ro.ecu.edu.au/context/ecuworkspost2013/article/6824/viewcontent/bg_16_309_2019.pdf |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.5194/bg-16-309-2019 |
container_title |
Biogeosciences |
container_volume |
16 |
container_issue |
2 |
container_start_page |
309 |
op_container_end_page |
327 |
_version_ |
1768388140797526016 |