Carbon export and transfer to depth across the Southern Ocean Great Calcite Belt
Sequestration of carbon by the marine biological pump depends on the processes that alter, remineralize, and preserve particulate organic carbon (POC) during transit to the deep ocean. Here, we present data collected from the Great Calcite Belt, a calcite-rich band across the Southern Ocean surface,...
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ftcopernicus:oai:publications.copernicus.org:bg28507 2023-05-15T18:25:07+02:00 Carbon export and transfer to depth across the Southern Ocean Great Calcite Belt Rosengard, S. Z. Lam, P. J. Balch, W. M. Auro, M. E. Pike, S. Drapeau, D. Bowler, B. 2018-09-27 application/pdf https://doi.org/10.5194/bg-12-3953-2015 https://www.biogeosciences.net/12/3953/2015/ eng eng doi:10.5194/bg-12-3953-2015 https://www.biogeosciences.net/12/3953/2015/ eISSN: 1726-4189 Text 2018 ftcopernicus https://doi.org/10.5194/bg-12-3953-2015 2019-12-24T09:53:20Z Sequestration of carbon by the marine biological pump depends on the processes that alter, remineralize, and preserve particulate organic carbon (POC) during transit to the deep ocean. Here, we present data collected from the Great Calcite Belt, a calcite-rich band across the Southern Ocean surface, to compare the transformation of POC in the euphotic and mesopelagic zones of the water column. The 234 Th-derived export fluxes and size-fractionated concentrations of POC, particulate inorganic carbon (PIC), and biogenic silica (BSi) were measured from the upper 1000 m of 27 stations across the Atlantic and Indian sectors of the Great Calcite Belt. POC export out of the euphotic zone was correlated with BSi export. PIC export was not, but did correlate positively with POC flux transfer efficiency. Moreover, regions of high BSi concentrations, which corresponded to regions with proportionally larger particles, exhibited higher attenuation of > 51 μm POC concentrations in the mesopelagic zone. The interplay among POC size partitioning, mineral composition, and POC attenuation suggests a more fundamental driver of POC transfer through both depth regimes in the Great Calcite Belt. In particular, we argue that diatom-rich communities produce large and labile POC aggregates, which not only generate high export fluxes but also drive more remineralization in the mesopelagic zone. We observe the opposite in communities with smaller calcifying phytoplankton, such as coccolithophores. We hypothesize that these differences are influenced by inherent differences in the lability of POC exported by different phytoplankton communities. Text Southern Ocean Copernicus Publications: E-Journals Indian Southern Ocean Biogeosciences 12 13 3953 3971 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
Sequestration of carbon by the marine biological pump depends on the processes that alter, remineralize, and preserve particulate organic carbon (POC) during transit to the deep ocean. Here, we present data collected from the Great Calcite Belt, a calcite-rich band across the Southern Ocean surface, to compare the transformation of POC in the euphotic and mesopelagic zones of the water column. The 234 Th-derived export fluxes and size-fractionated concentrations of POC, particulate inorganic carbon (PIC), and biogenic silica (BSi) were measured from the upper 1000 m of 27 stations across the Atlantic and Indian sectors of the Great Calcite Belt. POC export out of the euphotic zone was correlated with BSi export. PIC export was not, but did correlate positively with POC flux transfer efficiency. Moreover, regions of high BSi concentrations, which corresponded to regions with proportionally larger particles, exhibited higher attenuation of > 51 μm POC concentrations in the mesopelagic zone. The interplay among POC size partitioning, mineral composition, and POC attenuation suggests a more fundamental driver of POC transfer through both depth regimes in the Great Calcite Belt. In particular, we argue that diatom-rich communities produce large and labile POC aggregates, which not only generate high export fluxes but also drive more remineralization in the mesopelagic zone. We observe the opposite in communities with smaller calcifying phytoplankton, such as coccolithophores. We hypothesize that these differences are influenced by inherent differences in the lability of POC exported by different phytoplankton communities. |
format |
Text |
author |
Rosengard, S. Z. Lam, P. J. Balch, W. M. Auro, M. E. Pike, S. Drapeau, D. Bowler, B. |
spellingShingle |
Rosengard, S. Z. Lam, P. J. Balch, W. M. Auro, M. E. Pike, S. Drapeau, D. Bowler, B. Carbon export and transfer to depth across the Southern Ocean Great Calcite Belt |
author_facet |
Rosengard, S. Z. Lam, P. J. Balch, W. M. Auro, M. E. Pike, S. Drapeau, D. Bowler, B. |
author_sort |
Rosengard, S. Z. |
title |
Carbon export and transfer to depth across the Southern Ocean Great Calcite Belt |
title_short |
Carbon export and transfer to depth across the Southern Ocean Great Calcite Belt |
title_full |
Carbon export and transfer to depth across the Southern Ocean Great Calcite Belt |
title_fullStr |
Carbon export and transfer to depth across the Southern Ocean Great Calcite Belt |
title_full_unstemmed |
Carbon export and transfer to depth across the Southern Ocean Great Calcite Belt |
title_sort |
carbon export and transfer to depth across the southern ocean great calcite belt |
publishDate |
2018 |
url |
https://doi.org/10.5194/bg-12-3953-2015 https://www.biogeosciences.net/12/3953/2015/ |
geographic |
Indian Southern Ocean |
geographic_facet |
Indian Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
eISSN: 1726-4189 |
op_relation |
doi:10.5194/bg-12-3953-2015 https://www.biogeosciences.net/12/3953/2015/ |
op_doi |
https://doi.org/10.5194/bg-12-3953-2015 |
container_title |
Biogeosciences |
container_volume |
12 |
container_issue |
13 |
container_start_page |
3953 |
op_container_end_page |
3971 |
_version_ |
1766206339769434112 |