Barium in twilight zone suspended matter as a potential proxy for particulate organic carbon remineralization: results for the North Pacific
This study focuses on the fate of exported organic carbon in the twilight zone at two contrasting environments in the North Pacific: the oligotrophic ALOHA site (2245′N, 158W; Hawaii; studied during JuneJuly 2004) and the mesotrophic Subarctic Pacific K2 site (47N, 161W; studied during JulyAugust 20...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
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2008
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Online Access: | https://doi.org/10.1016/j.dsr2.2008.04.020 http://ecite.utas.edu.au/95537 |
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ftunivtasecite:oai:ecite.utas.edu.au:95537 2023-05-15T18:26:00+02:00 Barium in twilight zone suspended matter as a potential proxy for particulate organic carbon remineralization: results for the North Pacific Dehairs, F Jacquet, S Savoye, N Van Mooy, BAS Buesseler, KO Bishop, JKB Lamborg, CH Elskens, M Baeyens, W Boyd, PW Casciotti, KL Monnin, C 2008 https://doi.org/10.1016/j.dsr2.2008.04.020 http://ecite.utas.edu.au/95537 en eng Pergamon-Elsevier Science Ltd http://dx.doi.org/10.1016/j.dsr2.2008.04.020 Dehairs, F and Jacquet, S and Savoye, N and Van Mooy, BAS and Buesseler, KO and Bishop, JKB and Lamborg, CH and Elskens, M and Baeyens, W and Boyd, PW and Casciotti, KL and Monnin, C, Barium in twilight zone suspended matter as a potential proxy for particulate organic carbon remineralization: results for the North Pacific, Deep-Sea Research Part 2, 55, (14-15) pp. 1673-1683. ISSN 0967-0645 (2008) [Refereed Article] http://ecite.utas.edu.au/95537 Earth Sciences Oceanography Chemical Oceanography Refereed Article PeerReviewed 2008 ftunivtasecite https://doi.org/10.1016/j.dsr2.2008.04.020 2019-12-13T21:57:57Z This study focuses on the fate of exported organic carbon in the twilight zone at two contrasting environments in the North Pacific: the oligotrophic ALOHA site (2245′N, 158W; Hawaii; studied during JuneJuly 2004) and the mesotrophic Subarctic Pacific K2 site (47N, 161W; studied during JulyAugust 2005). Earlier work has shown that non-lithogenic, excess particulate Ba (Ba xs ) in the mesopelagic water column is a potential proxy of organic carbon remineralization. In general, Ba xs contents were significantly larger at K2 than at ALOHA. At ALOHA, the Ba xs profiles from repeated sampling (five casts) showed remarkable consistency over a period of three weeks, suggesting that the system was close to being at steady state. In contrast, more variability was observed at K2 (six casts sampled), reflecting the more dynamic physical and biological conditions prevailing in this environment. While for both sites Ba xs concentrations increased with depth, at K2 a clear maximum was present between the base of the mixed layer at around 50 and 500 m, reflecting production and release of Ba xs . Larger mesopelagic Ba xs contents and larger bacterial production in the twilight zone at the K2 site indicate that more material was exported from the upper mixed layer for bacterial degradation deeper, compared to the ALOHA site. Furthermore, application of a published transfer function [Dehairs, F., Shopova, D., Ober, S., Veth, C., Goeyens, L., 1997. Particulate barium stocks and oxygen consumption in the Southern Ocean mesopelagic water column during spring and early summer: relationship with export production. Deep-Sea Research II 44(12), 497516] relating oxygen consumption to the observed Baxs data indicated that the latter were in good agreement with bacterial respiration, calculated from bacterial production. These results corroborate earlier findings highlighting the potential of Ba xs as a proxy for organic carbon remineralization. The range of POC remineralization rates calculated from twilight zone excess particulate Ba contents also compared well with the depth dependent POC flux decrease as recorded by neutrally buoyant sediment traps, except in one case (out of four). This discrepancy could indicate that differences in sinking velocities cause an uncoupling of the processes occurring in the fine suspended particle pool from those affecting the larger particle pool which sustains the vertical flux, thus rendering comparison between both approaches risky. Article in Journal/Newspaper Southern Ocean Subarctic eCite UTAS (University of Tasmania) Pacific Southern Ocean Deep Sea Research Part II: Topical Studies in Oceanography 55 14-15 1673 1683 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Oceanography Chemical Oceanography |
spellingShingle |
Earth Sciences Oceanography Chemical Oceanography Dehairs, F Jacquet, S Savoye, N Van Mooy, BAS Buesseler, KO Bishop, JKB Lamborg, CH Elskens, M Baeyens, W Boyd, PW Casciotti, KL Monnin, C Barium in twilight zone suspended matter as a potential proxy for particulate organic carbon remineralization: results for the North Pacific |
topic_facet |
Earth Sciences Oceanography Chemical Oceanography |
description |
This study focuses on the fate of exported organic carbon in the twilight zone at two contrasting environments in the North Pacific: the oligotrophic ALOHA site (2245′N, 158W; Hawaii; studied during JuneJuly 2004) and the mesotrophic Subarctic Pacific K2 site (47N, 161W; studied during JulyAugust 2005). Earlier work has shown that non-lithogenic, excess particulate Ba (Ba xs ) in the mesopelagic water column is a potential proxy of organic carbon remineralization. In general, Ba xs contents were significantly larger at K2 than at ALOHA. At ALOHA, the Ba xs profiles from repeated sampling (five casts) showed remarkable consistency over a period of three weeks, suggesting that the system was close to being at steady state. In contrast, more variability was observed at K2 (six casts sampled), reflecting the more dynamic physical and biological conditions prevailing in this environment. While for both sites Ba xs concentrations increased with depth, at K2 a clear maximum was present between the base of the mixed layer at around 50 and 500 m, reflecting production and release of Ba xs . Larger mesopelagic Ba xs contents and larger bacterial production in the twilight zone at the K2 site indicate that more material was exported from the upper mixed layer for bacterial degradation deeper, compared to the ALOHA site. Furthermore, application of a published transfer function [Dehairs, F., Shopova, D., Ober, S., Veth, C., Goeyens, L., 1997. Particulate barium stocks and oxygen consumption in the Southern Ocean mesopelagic water column during spring and early summer: relationship with export production. Deep-Sea Research II 44(12), 497516] relating oxygen consumption to the observed Baxs data indicated that the latter were in good agreement with bacterial respiration, calculated from bacterial production. These results corroborate earlier findings highlighting the potential of Ba xs as a proxy for organic carbon remineralization. The range of POC remineralization rates calculated from twilight zone excess particulate Ba contents also compared well with the depth dependent POC flux decrease as recorded by neutrally buoyant sediment traps, except in one case (out of four). This discrepancy could indicate that differences in sinking velocities cause an uncoupling of the processes occurring in the fine suspended particle pool from those affecting the larger particle pool which sustains the vertical flux, thus rendering comparison between both approaches risky. |
format |
Article in Journal/Newspaper |
author |
Dehairs, F Jacquet, S Savoye, N Van Mooy, BAS Buesseler, KO Bishop, JKB Lamborg, CH Elskens, M Baeyens, W Boyd, PW Casciotti, KL Monnin, C |
author_facet |
Dehairs, F Jacquet, S Savoye, N Van Mooy, BAS Buesseler, KO Bishop, JKB Lamborg, CH Elskens, M Baeyens, W Boyd, PW Casciotti, KL Monnin, C |
author_sort |
Dehairs, F |
title |
Barium in twilight zone suspended matter as a potential proxy for particulate organic carbon remineralization: results for the North Pacific |
title_short |
Barium in twilight zone suspended matter as a potential proxy for particulate organic carbon remineralization: results for the North Pacific |
title_full |
Barium in twilight zone suspended matter as a potential proxy for particulate organic carbon remineralization: results for the North Pacific |
title_fullStr |
Barium in twilight zone suspended matter as a potential proxy for particulate organic carbon remineralization: results for the North Pacific |
title_full_unstemmed |
Barium in twilight zone suspended matter as a potential proxy for particulate organic carbon remineralization: results for the North Pacific |
title_sort |
barium in twilight zone suspended matter as a potential proxy for particulate organic carbon remineralization: results for the north pacific |
publisher |
Pergamon-Elsevier Science Ltd |
publishDate |
2008 |
url |
https://doi.org/10.1016/j.dsr2.2008.04.020 http://ecite.utas.edu.au/95537 |
geographic |
Pacific Southern Ocean |
geographic_facet |
Pacific Southern Ocean |
genre |
Southern Ocean Subarctic |
genre_facet |
Southern Ocean Subarctic |
op_relation |
http://dx.doi.org/10.1016/j.dsr2.2008.04.020 Dehairs, F and Jacquet, S and Savoye, N and Van Mooy, BAS and Buesseler, KO and Bishop, JKB and Lamborg, CH and Elskens, M and Baeyens, W and Boyd, PW and Casciotti, KL and Monnin, C, Barium in twilight zone suspended matter as a potential proxy for particulate organic carbon remineralization: results for the North Pacific, Deep-Sea Research Part 2, 55, (14-15) pp. 1673-1683. ISSN 0967-0645 (2008) [Refereed Article] http://ecite.utas.edu.au/95537 |
op_doi |
https://doi.org/10.1016/j.dsr2.2008.04.020 |
container_title |
Deep Sea Research Part II: Topical Studies in Oceanography |
container_volume |
55 |
container_issue |
14-15 |
container_start_page |
1673 |
op_container_end_page |
1683 |
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1766207773175971840 |