Biological production in the Bellingshausen Sea from oxygen-to-argon ratios and oxygen triple isotopes
We present estimates of mixed-layer net community oxygen production ( N ) and gross oxygen production ( G ) of the Bellingshausen Sea in March and April 2007. N was derived from oxygen-to-argon (O 2 /Ar) ratios; G was derived using the dual-delta method from triple oxygen isotope measurements. In ad...
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2013
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ftdoajarticles:oai:doaj.org/article:c0a9c4bd9fe9413b8a4ae6c009d17883 2023-05-15T15:41:23+02:00 Biological production in the Bellingshausen Sea from oxygen-to-argon ratios and oxygen triple isotopes K. Castro-Morales N. Cassar D. R. Shoosmith J. Kaiser 2013-04-01T00:00:00Z https://doi.org/10.5194/bg-10-2273-2013 https://doaj.org/article/c0a9c4bd9fe9413b8a4ae6c009d17883 EN eng Copernicus Publications http://www.biogeosciences.net/10/2273/2013/bg-10-2273-2013.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-10-2273-2013 1726-4170 1726-4189 https://doaj.org/article/c0a9c4bd9fe9413b8a4ae6c009d17883 Biogeosciences, Vol 10, Iss 4, Pp 2273-2291 (2013) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2013 ftdoajarticles https://doi.org/10.5194/bg-10-2273-2013 2022-12-31T15:26:49Z We present estimates of mixed-layer net community oxygen production ( N ) and gross oxygen production ( G ) of the Bellingshausen Sea in March and April 2007. N was derived from oxygen-to-argon (O 2 /Ar) ratios; G was derived using the dual-delta method from triple oxygen isotope measurements. In addition, O 2 profiles were collected at 253 CTD stations. N is often approximated by the biological oxygen air–sea exchange flux ( F bio based on the O 2 /Ar supersaturation, assuming that significant horizontal or vertical fluxes are absent. Here we show that the effect of vertical fluxes alone can account for F bio values < 0 in large parts of the Bellingshausen Sea towards the end of the productive season, which could otherwise be mistaken to represent net heterotrophy. Thus, improved estimates of mixed-layer N can be derived from the sum of F bio , F e (entrainment from the upper thermocline during mixed-layer deepening) and F v (diapycnal eddy diffusion across the base of the mixed layer). In the winter sea ice zone (WSIZ), the corresponding correction results in a small change of F bio = (30 ± 17) mmol m −2 d −1 to N = (34 ± 17) mmol m −2 d −1 . However, in the permanent open ocean zone (POOZ), the original F bio value of (−17 ± 10) mmol m −2 d −1 gives a corrected value for N of (−2 ± 18) mmol m −2 d −1 . We hypothesize that in the WSIZ, enhanced water column stability due to the release of freshwater and nutrients from sea ice melt may account for the higher N value. These results stress the importance of accounting for physical biases when estimating mixed-layer marine productivity from in situ O 2 /Ar ratios. Article in Journal/Newspaper Bellingshausen Sea Sea ice Directory of Open Access Journals: DOAJ Articles Bellingshausen Sea Biogeosciences 10 4 2273 2291 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 K. Castro-Morales N. Cassar D. R. Shoosmith J. Kaiser Biological production in the Bellingshausen Sea from oxygen-to-argon ratios and oxygen triple isotopes |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
We present estimates of mixed-layer net community oxygen production ( N ) and gross oxygen production ( G ) of the Bellingshausen Sea in March and April 2007. N was derived from oxygen-to-argon (O 2 /Ar) ratios; G was derived using the dual-delta method from triple oxygen isotope measurements. In addition, O 2 profiles were collected at 253 CTD stations. N is often approximated by the biological oxygen air–sea exchange flux ( F bio based on the O 2 /Ar supersaturation, assuming that significant horizontal or vertical fluxes are absent. Here we show that the effect of vertical fluxes alone can account for F bio values < 0 in large parts of the Bellingshausen Sea towards the end of the productive season, which could otherwise be mistaken to represent net heterotrophy. Thus, improved estimates of mixed-layer N can be derived from the sum of F bio , F e (entrainment from the upper thermocline during mixed-layer deepening) and F v (diapycnal eddy diffusion across the base of the mixed layer). In the winter sea ice zone (WSIZ), the corresponding correction results in a small change of F bio = (30 ± 17) mmol m −2 d −1 to N = (34 ± 17) mmol m −2 d −1 . However, in the permanent open ocean zone (POOZ), the original F bio value of (−17 ± 10) mmol m −2 d −1 gives a corrected value for N of (−2 ± 18) mmol m −2 d −1 . We hypothesize that in the WSIZ, enhanced water column stability due to the release of freshwater and nutrients from sea ice melt may account for the higher N value. These results stress the importance of accounting for physical biases when estimating mixed-layer marine productivity from in situ O 2 /Ar ratios. |
format |
Article in Journal/Newspaper |
author |
K. Castro-Morales N. Cassar D. R. Shoosmith J. Kaiser |
author_facet |
K. Castro-Morales N. Cassar D. R. Shoosmith J. Kaiser |
author_sort |
K. Castro-Morales |
title |
Biological production in the Bellingshausen Sea from oxygen-to-argon ratios and oxygen triple isotopes |
title_short |
Biological production in the Bellingshausen Sea from oxygen-to-argon ratios and oxygen triple isotopes |
title_full |
Biological production in the Bellingshausen Sea from oxygen-to-argon ratios and oxygen triple isotopes |
title_fullStr |
Biological production in the Bellingshausen Sea from oxygen-to-argon ratios and oxygen triple isotopes |
title_full_unstemmed |
Biological production in the Bellingshausen Sea from oxygen-to-argon ratios and oxygen triple isotopes |
title_sort |
biological production in the bellingshausen sea from oxygen-to-argon ratios and oxygen triple isotopes |
publisher |
Copernicus Publications |
publishDate |
2013 |
url |
https://doi.org/10.5194/bg-10-2273-2013 https://doaj.org/article/c0a9c4bd9fe9413b8a4ae6c009d17883 |
geographic |
Bellingshausen Sea |
geographic_facet |
Bellingshausen Sea |
genre |
Bellingshausen Sea Sea ice |
genre_facet |
Bellingshausen Sea Sea ice |
op_source |
Biogeosciences, Vol 10, Iss 4, Pp 2273-2291 (2013) |
op_relation |
http://www.biogeosciences.net/10/2273/2013/bg-10-2273-2013.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-10-2273-2013 1726-4170 1726-4189 https://doaj.org/article/c0a9c4bd9fe9413b8a4ae6c009d17883 |
op_doi |
https://doi.org/10.5194/bg-10-2273-2013 |
container_title |
Biogeosciences |
container_volume |
10 |
container_issue |
4 |
container_start_page |
2273 |
op_container_end_page |
2291 |
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1766374287300624384 |