Low pCO2 under sea-ice melt in the Canada Basin of the western Arctic Ocean
In September 2013, we observed an expanse of surface water with low CO 2 partial pressure ( p CO 2 sea ) (< 200 µatm) in the Chukchi Sea of the western Arctic Ocean. The large undersaturation of CO 2 in this region was the result of massive primary production after the sea-ice retreat in June and...
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ftcopernicus:oai:publications.copernicus.org:bg58538 2023-05-15T15:00:36+02:00 Low pCO2 under sea-ice melt in the Canada Basin of the western Arctic Ocean Kosugi, Naohiro Sasano, Daisuke Ishii, Masao Nishino, Shigeto Uchida, Hiroshi Yoshikawa-Inoue, Hisayuki 2018-09-27 application/pdf https://doi.org/10.5194/bg-14-5727-2017 https://www.biogeosciences.net/14/5727/2017/ eng eng doi:10.5194/bg-14-5727-2017 https://www.biogeosciences.net/14/5727/2017/ eISSN: 1726-4189 Text 2018 ftcopernicus https://doi.org/10.5194/bg-14-5727-2017 2019-12-24T09:50:46Z In September 2013, we observed an expanse of surface water with low CO 2 partial pressure ( p CO 2 sea ) (< 200 µatm) in the Chukchi Sea of the western Arctic Ocean. The large undersaturation of CO 2 in this region was the result of massive primary production after the sea-ice retreat in June and July. In the surface of the Canada Basin, salinity was low (< 27) and p CO 2 sea was closer to the air–sea CO 2 equilibrium (∼ 360 µatm). From the relationships between salinity and total alkalinity, we confirmed that the low salinity in the Canada Basin was due to the larger fraction of meltwater input (∼ 0.16) rather than the riverine discharge (∼ 0.1). Such an increase in p CO 2 sea was not so clear in the coastal region near Point Barrow, where the fraction of riverine discharge was larger than that of sea-ice melt. We also identified low p CO 2 sea (< 250 µatm) in the depth of 30–50 m under the halocline of the Canada Basin. This subsurface low p CO 2 sea was attributed to the advection of Pacific-origin water, in which dissolved inorganic carbon is relatively low, through the Chukchi Sea where net primary production is high. Oxygen supersaturation (> 20 µmol kg −1 ) in the subsurface low p CO 2 sea layer in the Canada Basin indicated significant net primary production undersea and/or in preformed condition. If these low p CO 2 sea layers surface by wind mixing, they will act as additional CO 2 sinks; however, this is unlikely because intensification of stratification by sea-ice melt inhibits mixing across the halocline. Text Arctic Arctic Ocean canada basin Chukchi Chukchi Sea Point Barrow Sea ice Copernicus Publications: E-Journals Arctic Arctic Ocean Canada Chukchi Sea Pacific Biogeosciences 14 24 5727 5739 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
In September 2013, we observed an expanse of surface water with low CO 2 partial pressure ( p CO 2 sea ) (< 200 µatm) in the Chukchi Sea of the western Arctic Ocean. The large undersaturation of CO 2 in this region was the result of massive primary production after the sea-ice retreat in June and July. In the surface of the Canada Basin, salinity was low (< 27) and p CO 2 sea was closer to the air–sea CO 2 equilibrium (∼ 360 µatm). From the relationships between salinity and total alkalinity, we confirmed that the low salinity in the Canada Basin was due to the larger fraction of meltwater input (∼ 0.16) rather than the riverine discharge (∼ 0.1). Such an increase in p CO 2 sea was not so clear in the coastal region near Point Barrow, where the fraction of riverine discharge was larger than that of sea-ice melt. We also identified low p CO 2 sea (< 250 µatm) in the depth of 30–50 m under the halocline of the Canada Basin. This subsurface low p CO 2 sea was attributed to the advection of Pacific-origin water, in which dissolved inorganic carbon is relatively low, through the Chukchi Sea where net primary production is high. Oxygen supersaturation (> 20 µmol kg −1 ) in the subsurface low p CO 2 sea layer in the Canada Basin indicated significant net primary production undersea and/or in preformed condition. If these low p CO 2 sea layers surface by wind mixing, they will act as additional CO 2 sinks; however, this is unlikely because intensification of stratification by sea-ice melt inhibits mixing across the halocline. |
format |
Text |
author |
Kosugi, Naohiro Sasano, Daisuke Ishii, Masao Nishino, Shigeto Uchida, Hiroshi Yoshikawa-Inoue, Hisayuki |
spellingShingle |
Kosugi, Naohiro Sasano, Daisuke Ishii, Masao Nishino, Shigeto Uchida, Hiroshi Yoshikawa-Inoue, Hisayuki Low pCO2 under sea-ice melt in the Canada Basin of the western Arctic Ocean |
author_facet |
Kosugi, Naohiro Sasano, Daisuke Ishii, Masao Nishino, Shigeto Uchida, Hiroshi Yoshikawa-Inoue, Hisayuki |
author_sort |
Kosugi, Naohiro |
title |
Low pCO2 under sea-ice melt in the Canada Basin of the western Arctic Ocean |
title_short |
Low pCO2 under sea-ice melt in the Canada Basin of the western Arctic Ocean |
title_full |
Low pCO2 under sea-ice melt in the Canada Basin of the western Arctic Ocean |
title_fullStr |
Low pCO2 under sea-ice melt in the Canada Basin of the western Arctic Ocean |
title_full_unstemmed |
Low pCO2 under sea-ice melt in the Canada Basin of the western Arctic Ocean |
title_sort |
low pco2 under sea-ice melt in the canada basin of the western arctic ocean |
publishDate |
2018 |
url |
https://doi.org/10.5194/bg-14-5727-2017 https://www.biogeosciences.net/14/5727/2017/ |
geographic |
Arctic Arctic Ocean Canada Chukchi Sea Pacific |
geographic_facet |
Arctic Arctic Ocean Canada Chukchi Sea Pacific |
genre |
Arctic Arctic Ocean canada basin Chukchi Chukchi Sea Point Barrow Sea ice |
genre_facet |
Arctic Arctic Ocean canada basin Chukchi Chukchi Sea Point Barrow Sea ice |
op_source |
eISSN: 1726-4189 |
op_relation |
doi:10.5194/bg-14-5727-2017 https://www.biogeosciences.net/14/5727/2017/ |
op_doi |
https://doi.org/10.5194/bg-14-5727-2017 |
container_title |
Biogeosciences |
container_volume |
14 |
container_issue |
24 |
container_start_page |
5727 |
op_container_end_page |
5739 |
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1766332678627393536 |