Sinking Diatom Assemblages as a Key Driver for Deep Carbon and Silicon Export in the Scotia Sea (Southern Ocean)
Physical and biogeochemical processes in the Southern Ocean are fundamental for modulating global climate. In this context, a process-based understanding of how Antarctic diatoms control primary production and carbon export, and hence global-ocean carbon sequestration, has been identified as a scien...
Published in: | Frontiers in Earth Science |
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Online Access: | http://dx.doi.org/10.3389/feart.2021.579198 https://www.frontiersin.org/articles/10.3389/feart.2021.579198/full |
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crfrontiers:10.3389/feart.2021.579198 2024-09-15T17:48:04+00:00 Sinking Diatom Assemblages as a Key Driver for Deep Carbon and Silicon Export in the Scotia Sea (Southern Ocean) Zú�iga, D. Sanchez-Vidal, A. Flexas, M. M. Carroll, D. Rufino, M. M. Spreen, G. Calafat, A. Abrantes, F. Ministerio de Ciencia y Tecnología Fundação para a Ciência e a Tecnologia Generalitat de Catalunya 2021 http://dx.doi.org/10.3389/feart.2021.579198 https://www.frontiersin.org/articles/10.3389/feart.2021.579198/full unknown Frontiers Media SA https://creativecommons.org/licenses/by/4.0/ Frontiers in Earth Science volume 9 ISSN 2296-6463 journal-article 2021 crfrontiers https://doi.org/10.3389/feart.2021.579198 2024-08-27T04:05:23Z Physical and biogeochemical processes in the Southern Ocean are fundamental for modulating global climate. In this context, a process-based understanding of how Antarctic diatoms control primary production and carbon export, and hence global-ocean carbon sequestration, has been identified as a scientific priority. Here we use novel sediment trap observations in combination with a data-assimilative ocean biogeochemistry model (ECCO-Darwin) to understand how environmental conditions trigger diatom ecology in the iron-fertilized southern Scotia Sea. We unravel the role of diatoms assemblage in controlling the biogeochemistry of sinking material escaping from the euphotic zone, and discuss the link between changes in upper-ocean environmental conditions and the composition of settling material exported from the surface to 1,000 m depth from March 2012 to January 2013. The combined analysis of in situ observations and model simulation suggests that an anomalous sea-ice episode in early summer 2012–2013 favored ( via restratification due to sea-ice melt) an early massive bloom of Corethron pennatum that rapidly sank to depth. This event drove high biogenic silicon to organic carbon export ratios, while modulating the carbon and nitrogen isotopic signals of sinking organic matter reaching the deep ocean. Our findings highlight the role of diatom ecology in modulating silicon vs. carbon sequestration efficiency, a critical factor for determining the stoichiometric relationship of limiting nutrients in the Southern Ocean. Article in Journal/Newspaper Antarc* Antarctic Scotia Sea Sea ice Southern Ocean Frontiers (Publisher) Frontiers in Earth Science 9 |
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Frontiers (Publisher) |
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Physical and biogeochemical processes in the Southern Ocean are fundamental for modulating global climate. In this context, a process-based understanding of how Antarctic diatoms control primary production and carbon export, and hence global-ocean carbon sequestration, has been identified as a scientific priority. Here we use novel sediment trap observations in combination with a data-assimilative ocean biogeochemistry model (ECCO-Darwin) to understand how environmental conditions trigger diatom ecology in the iron-fertilized southern Scotia Sea. We unravel the role of diatoms assemblage in controlling the biogeochemistry of sinking material escaping from the euphotic zone, and discuss the link between changes in upper-ocean environmental conditions and the composition of settling material exported from the surface to 1,000 m depth from March 2012 to January 2013. The combined analysis of in situ observations and model simulation suggests that an anomalous sea-ice episode in early summer 2012–2013 favored ( via restratification due to sea-ice melt) an early massive bloom of Corethron pennatum that rapidly sank to depth. This event drove high biogenic silicon to organic carbon export ratios, while modulating the carbon and nitrogen isotopic signals of sinking organic matter reaching the deep ocean. Our findings highlight the role of diatom ecology in modulating silicon vs. carbon sequestration efficiency, a critical factor for determining the stoichiometric relationship of limiting nutrients in the Southern Ocean. |
author2 |
Ministerio de Ciencia y Tecnología Fundação para a Ciência e a Tecnologia Generalitat de Catalunya |
format |
Article in Journal/Newspaper |
author |
Zú�iga, D. Sanchez-Vidal, A. Flexas, M. M. Carroll, D. Rufino, M. M. Spreen, G. Calafat, A. Abrantes, F. |
spellingShingle |
Zú�iga, D. Sanchez-Vidal, A. Flexas, M. M. Carroll, D. Rufino, M. M. Spreen, G. Calafat, A. Abrantes, F. Sinking Diatom Assemblages as a Key Driver for Deep Carbon and Silicon Export in the Scotia Sea (Southern Ocean) |
author_facet |
Zú�iga, D. Sanchez-Vidal, A. Flexas, M. M. Carroll, D. Rufino, M. M. Spreen, G. Calafat, A. Abrantes, F. |
author_sort |
Zú�iga, D. |
title |
Sinking Diatom Assemblages as a Key Driver for Deep Carbon and Silicon Export in the Scotia Sea (Southern Ocean) |
title_short |
Sinking Diatom Assemblages as a Key Driver for Deep Carbon and Silicon Export in the Scotia Sea (Southern Ocean) |
title_full |
Sinking Diatom Assemblages as a Key Driver for Deep Carbon and Silicon Export in the Scotia Sea (Southern Ocean) |
title_fullStr |
Sinking Diatom Assemblages as a Key Driver for Deep Carbon and Silicon Export in the Scotia Sea (Southern Ocean) |
title_full_unstemmed |
Sinking Diatom Assemblages as a Key Driver for Deep Carbon and Silicon Export in the Scotia Sea (Southern Ocean) |
title_sort |
sinking diatom assemblages as a key driver for deep carbon and silicon export in the scotia sea (southern ocean) |
publisher |
Frontiers Media SA |
publishDate |
2021 |
url |
http://dx.doi.org/10.3389/feart.2021.579198 https://www.frontiersin.org/articles/10.3389/feart.2021.579198/full |
genre |
Antarc* Antarctic Scotia Sea Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Scotia Sea Sea ice Southern Ocean |
op_source |
Frontiers in Earth Science volume 9 ISSN 2296-6463 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3389/feart.2021.579198 |
container_title |
Frontiers in Earth Science |
container_volume |
9 |
_version_ |
1810288955740913664 |