Particulate barium tracing of significant mesopelagic carbon remineralisation in the North Atlantic
<jats:p>Abstract. The remineralisation of sinking particles by prokaryotic heterotrophic activity is important for controlling oceanic carbon sequestration. Here, we report mesopelagic particulate organic carbon (POC) remineralisation fluxes in the North Atlantic along the GEOTRACES-GA01 secti...
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ftunivliverpool:oai:livrepository.liverpool.ac.uk:3034357 2023-05-15T17:06:13+02:00 Particulate barium tracing of significant mesopelagic carbon remineralisation in the North Atlantic Lemaitre, Nolwenn Planquette, Helene Planchon, Frederic Sarthou, Geraldine Jacquet, Stephanie Garcia-Ibanez, Maribel I Gourain, Arthur Cheize, Marie Monin, Laurence Andre, Luc Laha, Priya Terryn, Herman Dehairs, Frank 2018 http://livrepository.liverpool.ac.uk/3034357/ https://doi.org/10.5194/bg-15-2289-2018 en eng Copernicus GmbH Collapse authors list. Lemaitre, Nolwenn, Planquette, Helene, Planchon, Frederic, Sarthou, Geraldine, Jacquet, Stephanie, Garcia-Ibanez, Maribel I, Gourain, Arthur orcid:0000-0001-8288-6527 , Cheize, Marie, Monin, Laurence, Andre, Luc et al (show 3 more authors) , Laha, Priya, Terryn, Herman and Dehairs, Frank (2018) Particulate barium tracing of significant mesopelagic carbon remineralisation in the North Atlantic. BIOGEOSCIENCES, 15 (7). pp. 2289-2307. Article NonPeerReviewed 2018 ftunivliverpool https://doi.org/10.5194/bg-15-2289-2018 2023-01-19T23:35:45Z <jats:p>Abstract. The remineralisation of sinking particles by prokaryotic heterotrophic activity is important for controlling oceanic carbon sequestration. Here, we report mesopelagic particulate organic carbon (POC) remineralisation fluxes in the North Atlantic along the GEOTRACES-GA01 section (GEOVIDE cruise; May–June 2014) using the particulate biogenic barium (excess barium; Baxs) proxy. Important mesopelagic (100–1000 m) Baxs differences were observed along the transect depending on the intensity of past blooms, the phytoplankton community structure, and the physical forcing, including downwelling. The subpolar province was characterized by the highest mesopelagic Baxs content (up to 727 pmol L−1), which was attributed to an intense bloom averaging 6 mg chl a m−3 between January and June 2014 and by an intense 1500 m deep convection in the central Labrador Sea during the winter preceding the sampling. This downwelling could have promoted a deepening of the prokaryotic heterotrophic activity, increasing the Baxs content. In comparison, the temperate province, characterized by the lowest Baxs content (391 pmol L−1), was sampled during the bloom period and phytoplankton appear to be dominated by small and calcifying species, such as coccolithophorids. The Baxs content, related to oxygen consumption, was converted into a remineralisation flux using an updated relationship, proposed for the first time in the North Atlantic. The estimated fluxes were of the same order of magnitude as other fluxes obtained using independent methods (moored sediment traps, incubations) in the North Atlantic. Interestingly, in the subpolar and subtropical provinces, mesopelagic POC remineralisation fluxes (up to 13 and 4.6 mmol C m−2 d−1, respectively) were equalling and occasionally even exceeding upper-ocean POC export fluxes, deduced using the 234Th method. These results highlight the important impact of the mesopelagic remineralisation on the biological carbon pump of the studied area with a near-zero, deep (> 1000 m) ... Article in Journal/Newspaper Labrador Sea North Atlantic The University of Liverpool Repository Biogeosciences 15 8 2289 2307 |
institution |
Open Polar |
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The University of Liverpool Repository |
op_collection_id |
ftunivliverpool |
language |
English |
description |
<jats:p>Abstract. The remineralisation of sinking particles by prokaryotic heterotrophic activity is important for controlling oceanic carbon sequestration. Here, we report mesopelagic particulate organic carbon (POC) remineralisation fluxes in the North Atlantic along the GEOTRACES-GA01 section (GEOVIDE cruise; May–June 2014) using the particulate biogenic barium (excess barium; Baxs) proxy. Important mesopelagic (100–1000 m) Baxs differences were observed along the transect depending on the intensity of past blooms, the phytoplankton community structure, and the physical forcing, including downwelling. The subpolar province was characterized by the highest mesopelagic Baxs content (up to 727 pmol L−1), which was attributed to an intense bloom averaging 6 mg chl a m−3 between January and June 2014 and by an intense 1500 m deep convection in the central Labrador Sea during the winter preceding the sampling. This downwelling could have promoted a deepening of the prokaryotic heterotrophic activity, increasing the Baxs content. In comparison, the temperate province, characterized by the lowest Baxs content (391 pmol L−1), was sampled during the bloom period and phytoplankton appear to be dominated by small and calcifying species, such as coccolithophorids. The Baxs content, related to oxygen consumption, was converted into a remineralisation flux using an updated relationship, proposed for the first time in the North Atlantic. The estimated fluxes were of the same order of magnitude as other fluxes obtained using independent methods (moored sediment traps, incubations) in the North Atlantic. Interestingly, in the subpolar and subtropical provinces, mesopelagic POC remineralisation fluxes (up to 13 and 4.6 mmol C m−2 d−1, respectively) were equalling and occasionally even exceeding upper-ocean POC export fluxes, deduced using the 234Th method. These results highlight the important impact of the mesopelagic remineralisation on the biological carbon pump of the studied area with a near-zero, deep (> 1000 m) ... |
format |
Article in Journal/Newspaper |
author |
Lemaitre, Nolwenn Planquette, Helene Planchon, Frederic Sarthou, Geraldine Jacquet, Stephanie Garcia-Ibanez, Maribel I Gourain, Arthur Cheize, Marie Monin, Laurence Andre, Luc Laha, Priya Terryn, Herman Dehairs, Frank |
spellingShingle |
Lemaitre, Nolwenn Planquette, Helene Planchon, Frederic Sarthou, Geraldine Jacquet, Stephanie Garcia-Ibanez, Maribel I Gourain, Arthur Cheize, Marie Monin, Laurence Andre, Luc Laha, Priya Terryn, Herman Dehairs, Frank Particulate barium tracing of significant mesopelagic carbon remineralisation in the North Atlantic |
author_facet |
Lemaitre, Nolwenn Planquette, Helene Planchon, Frederic Sarthou, Geraldine Jacquet, Stephanie Garcia-Ibanez, Maribel I Gourain, Arthur Cheize, Marie Monin, Laurence Andre, Luc Laha, Priya Terryn, Herman Dehairs, Frank |
author_sort |
Lemaitre, Nolwenn |
title |
Particulate barium tracing of significant mesopelagic carbon remineralisation in the North Atlantic |
title_short |
Particulate barium tracing of significant mesopelagic carbon remineralisation in the North Atlantic |
title_full |
Particulate barium tracing of significant mesopelagic carbon remineralisation in the North Atlantic |
title_fullStr |
Particulate barium tracing of significant mesopelagic carbon remineralisation in the North Atlantic |
title_full_unstemmed |
Particulate barium tracing of significant mesopelagic carbon remineralisation in the North Atlantic |
title_sort |
particulate barium tracing of significant mesopelagic carbon remineralisation in the north atlantic |
publisher |
Copernicus GmbH |
publishDate |
2018 |
url |
http://livrepository.liverpool.ac.uk/3034357/ https://doi.org/10.5194/bg-15-2289-2018 |
genre |
Labrador Sea North Atlantic |
genre_facet |
Labrador Sea North Atlantic |
op_relation |
Collapse authors list. Lemaitre, Nolwenn, Planquette, Helene, Planchon, Frederic, Sarthou, Geraldine, Jacquet, Stephanie, Garcia-Ibanez, Maribel I, Gourain, Arthur orcid:0000-0001-8288-6527 , Cheize, Marie, Monin, Laurence, Andre, Luc et al (show 3 more authors) , Laha, Priya, Terryn, Herman and Dehairs, Frank (2018) Particulate barium tracing of significant mesopelagic carbon remineralisation in the North Atlantic. BIOGEOSCIENCES, 15 (7). pp. 2289-2307. |
op_doi |
https://doi.org/10.5194/bg-15-2289-2018 |
container_title |
Biogeosciences |
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15 |
container_issue |
8 |
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2289 |
op_container_end_page |
2307 |
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1766061260981403648 |