A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean
The biological carbon pump (BCP) contributes to the oceanic CO2 sink by transferring particulate organic carbon (POC) into the deep ocean. The magnitude and efficiency of the BCP is likely to vary on timescales of days to seasons, however characterising this variability from shipboard observations i...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
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Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2023
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Online Access: | http://hdl.handle.net/10204/12896 https://doi.org/10.1016/j.dsr2.2023.105274 |
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ftcsir:oai:researchspace.csir.co.za:10204/12896 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
Council for Scientific and Industrial Research (South Africa): CSIR Research Space |
op_collection_id |
ftcsir |
language |
English |
topic |
Biological carbon pump BCP Particulate organic carbon POC Deep-sea research Oceanography |
spellingShingle |
Biological carbon pump BCP Particulate organic carbon POC Deep-sea research Oceanography Henson, SA Briggs, N Carvalho, F Manno, C Mignot, A Thomalla, Sandy J A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean |
topic_facet |
Biological carbon pump BCP Particulate organic carbon POC Deep-sea research Oceanography |
description |
The biological carbon pump (BCP) contributes to the oceanic CO2 sink by transferring particulate organic carbon (POC) into the deep ocean. The magnitude and efficiency of the BCP is likely to vary on timescales of days to seasons, however characterising this variability from shipboard observations is challenging. High resolution, sustained observations of primary production and particle fluxes by autonomous vehicles offer the potential to fill this knowledge gap. Here we present a 4 month, daily, 1 m vertical resolution glider dataset, collected in the high productivity bloom, downstream of South Georgia, Southern Ocean. The dataset reveals substantial temporal variability in primary production, POC flux and attenuation. During the pre-bloom peak phase we find high export efficiency, implying minimal heterotrophic POC consumption, i.e. productivity is decoupled from upper ocean remineralisation processes. As the bloom progresses from its peak through its declining phase, export flux decreases, but transfer efficiency within the upper 100 m of the mesopelagic increases. Conversely, transfer efficiency in the lower mesopelagic decreases in the post-bloom phase, implying that the flux attenuation processes operating in the upper and lower mesopelagic are effectively decoupled. This finding underscores an important limitation of using a single parameter, such as Martin's ‘b’, to characterise POC flux attenuation in a given location or season. Frequent pulses of export flux are observed throughout the deployment, indicating decoupling between primary production and the processes driving export of material from the upper ocean. The mechanisms underlying the observed seasonal changes in BCP magnitude and efficiency are unclear, as temperature and oxygen concentration changed minimally, although the nature of the sinking particles changed substantially as the bloom progressed. Our results highlight the difficulty of capturing temporal variability and episodic flux events with traditional shipboard observations, which ... |
format |
Article in Journal/Newspaper |
author |
Henson, SA Briggs, N Carvalho, F Manno, C Mignot, A Thomalla, Sandy J |
author_facet |
Henson, SA Briggs, N Carvalho, F Manno, C Mignot, A Thomalla, Sandy J |
author_sort |
Henson, SA |
title |
A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean |
title_short |
A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean |
title_full |
A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean |
title_fullStr |
A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean |
title_full_unstemmed |
A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean |
title_sort |
seasonal transition in biological carbon pump efficiency in the northern scotia sea, southern ocean |
publishDate |
2023 |
url |
http://hdl.handle.net/10204/12896 https://doi.org/10.1016/j.dsr2.2023.105274 |
geographic |
Southern Ocean Scotia Sea |
geographic_facet |
Southern Ocean Scotia Sea |
genre |
Scotia Sea Southern Ocean |
genre_facet |
Scotia Sea Southern Ocean |
op_source |
Deep-Sea Research Part II: Topical Studies in Oceanography, 208 |
op_relation |
https://www.sciencedirect.com/science/article/pii/S0967064523000243 Henson, S., Briggs, N., Carvalho, F., Manno, C., Mignot, A. & Thomalla, S.J. 2023. A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean. Deep-Sea Research Part II: Topical Studies in Oceanography, 208. http://hdl.handle.net/10204/12896 0967-0645 1879-0100 https://doi.org/10.1016/j.dsr2.2023.105274 http://hdl.handle.net/10204/12896 Henson, S., Briggs, N., Carvalho, F., Manno, C., Mignot, A., & Thomalla, S. J. (2023). A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean. Deep-Sea Research Part II: Topical Studies in Oceanography, 208 , http://hdl.handle.net/10204/12896 Henson, SA, N Briggs, F Carvalho, C Manno, A Mignot, and Sandy J Thomalla "A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean." Deep-Sea Research Part II: Topical Studies in Oceanography, 208 (2023) http://hdl.handle.net/10204/12896 Henson S, Briggs N, Carvalho F, Manno C, Mignot A, Thomalla SJ. A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean. Deep-Sea Research Part II: Topical Studies in Oceanography, 208. 2023; http://hdl.handle.net/10204/12896. 26624 |
op_rights |
Attribution-NonCommercial-NoDerivs 3.0 United States http://creativecommons.org/licenses/by-nc-nd/3.0/us/ |
op_doi |
https://doi.org/10.1016/j.dsr2.2023.105274 |
container_title |
Deep Sea Research Part II: Topical Studies in Oceanography |
container_volume |
208 |
container_start_page |
105274 |
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1774298501347278848 |
spelling |
ftcsir:oai:researchspace.csir.co.za:10204/12896 2023-08-15T12:43:01+02:00 A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean Henson, SA Briggs, N Carvalho, F Manno, C Mignot, A Thomalla, Sandy J 2023-04 Fulltext application/pdf http://hdl.handle.net/10204/12896 https://doi.org/10.1016/j.dsr2.2023.105274 en eng https://www.sciencedirect.com/science/article/pii/S0967064523000243 Henson, S., Briggs, N., Carvalho, F., Manno, C., Mignot, A. & Thomalla, S.J. 2023. A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean. Deep-Sea Research Part II: Topical Studies in Oceanography, 208. http://hdl.handle.net/10204/12896 0967-0645 1879-0100 https://doi.org/10.1016/j.dsr2.2023.105274 http://hdl.handle.net/10204/12896 Henson, S., Briggs, N., Carvalho, F., Manno, C., Mignot, A., & Thomalla, S. J. (2023). A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean. Deep-Sea Research Part II: Topical Studies in Oceanography, 208 , http://hdl.handle.net/10204/12896 Henson, SA, N Briggs, F Carvalho, C Manno, A Mignot, and Sandy J Thomalla "A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean." Deep-Sea Research Part II: Topical Studies in Oceanography, 208 (2023) http://hdl.handle.net/10204/12896 Henson S, Briggs N, Carvalho F, Manno C, Mignot A, Thomalla SJ. A seasonal transition in biological carbon pump efficiency in the northern Scotia Sea, Southern Ocean. Deep-Sea Research Part II: Topical Studies in Oceanography, 208. 2023; http://hdl.handle.net/10204/12896. 26624 Attribution-NonCommercial-NoDerivs 3.0 United States http://creativecommons.org/licenses/by-nc-nd/3.0/us/ Deep-Sea Research Part II: Topical Studies in Oceanography, 208 Biological carbon pump BCP Particulate organic carbon POC Deep-sea research Oceanography Article 2023 ftcsir https://doi.org/10.1016/j.dsr2.2023.105274 2023-07-25T23:47:53Z The biological carbon pump (BCP) contributes to the oceanic CO2 sink by transferring particulate organic carbon (POC) into the deep ocean. The magnitude and efficiency of the BCP is likely to vary on timescales of days to seasons, however characterising this variability from shipboard observations is challenging. High resolution, sustained observations of primary production and particle fluxes by autonomous vehicles offer the potential to fill this knowledge gap. Here we present a 4 month, daily, 1 m vertical resolution glider dataset, collected in the high productivity bloom, downstream of South Georgia, Southern Ocean. The dataset reveals substantial temporal variability in primary production, POC flux and attenuation. During the pre-bloom peak phase we find high export efficiency, implying minimal heterotrophic POC consumption, i.e. productivity is decoupled from upper ocean remineralisation processes. As the bloom progresses from its peak through its declining phase, export flux decreases, but transfer efficiency within the upper 100 m of the mesopelagic increases. Conversely, transfer efficiency in the lower mesopelagic decreases in the post-bloom phase, implying that the flux attenuation processes operating in the upper and lower mesopelagic are effectively decoupled. This finding underscores an important limitation of using a single parameter, such as Martin's ‘b’, to characterise POC flux attenuation in a given location or season. Frequent pulses of export flux are observed throughout the deployment, indicating decoupling between primary production and the processes driving export of material from the upper ocean. The mechanisms underlying the observed seasonal changes in BCP magnitude and efficiency are unclear, as temperature and oxygen concentration changed minimally, although the nature of the sinking particles changed substantially as the bloom progressed. Our results highlight the difficulty of capturing temporal variability and episodic flux events with traditional shipboard observations, which ... Article in Journal/Newspaper Scotia Sea Southern Ocean Council for Scientific and Industrial Research (South Africa): CSIR Research Space Southern Ocean Scotia Sea Deep Sea Research Part II: Topical Studies in Oceanography 208 105274 |