Decadal oxygen change in the eastern tropical North Atlantic
Repeat shipboard and multi-year moored observations obtained in the oxygen minimum zone (OMZ) of the eastern tropical North Atlantic (ETNA) were used to study the decadal change in oxygen for the period 2006–2015. Along 23° W between 6 and 14° N, oxygen decreased with a rate of −5.9 ± 3.5 µmol kg−1...
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Copernicus Publications (EGU)
2017
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ftoceanrep:oai:oceanrep.geomar.de:35550 2023-10-09T21:53:56+02:00 Decadal oxygen change in the eastern tropical North Atlantic Hahn, Johannes Brandt, Peter Schmidtko, Sunke Krahmann, Gerd 2017-07-06 text https://oceanrep.geomar.de/id/eprint/35550/ https://oceanrep.geomar.de/id/eprint/35550/1/os-2016-102.pdf https://oceanrep.geomar.de/id/eprint/35550/7/os-13-551-2017.pdf https://doi.org/10.5194/os-13-551-2017 en eng Copernicus Publications (EGU) https://oceanrep.geomar.de/id/eprint/35550/1/os-2016-102.pdf https://oceanrep.geomar.de/id/eprint/35550/7/os-13-551-2017.pdf Hahn, J. , Brandt, P. , Schmidtko, S. and Krahmann, G. (2017) Decadal oxygen change in the eastern tropical North Atlantic. Open Access Ocean Science, 13 (4). pp. 551-576. DOI 10.5194/os-13-551-2017 <https://doi.org/10.5194/os-13-551-2017>. doi:10.5194/os-13-551-2017 cc_by_3.0 info:eu-repo/semantics/openAccess Article PeerReviewed 2017 ftoceanrep https://doi.org/10.5194/os-13-551-2017 2023-09-24T23:21:40Z Repeat shipboard and multi-year moored observations obtained in the oxygen minimum zone (OMZ) of the eastern tropical North Atlantic (ETNA) were used to study the decadal change in oxygen for the period 2006–2015. Along 23° W between 6 and 14° N, oxygen decreased with a rate of −5.9 ± 3.5 µmol kg−1 decade−1 within the depth covering the deep oxycline (200–400 m), while below the OMZ core (400–1000 m) oxygen increased by 4.0 ± 1.6 µmol kg−1 decade−1 on average. The inclusion of these decadal oxygen trends in the recently estimated oxygen budget for the ETNA OMZ suggests a weakened ventilation of the upper 400 m, whereas the ventilation strengthened homogeneously below 400 m. The changed ventilation resulted in a shoaling of the ETNA OMZ of −0.03 ± 0.02 kg m−3 decade−1 in density space, which was only partly compensated by a deepening of isopycnal surfaces, thus pointing to a shoaling of the OMZ in depth space as well (−22 ± 17 m decade−1). Based on the improved oxygen budget, possible causes for the changed ventilation are analyzed and discussed. Largely ruling out other ventilation processes, the zonal advective oxygen supply stands out as the most probable budget term responsible for the decadal oxygen changes. Article in Journal/Newspaper North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Ocean Science 13 4 551 576 |
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Open Polar |
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OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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ftoceanrep |
language |
English |
description |
Repeat shipboard and multi-year moored observations obtained in the oxygen minimum zone (OMZ) of the eastern tropical North Atlantic (ETNA) were used to study the decadal change in oxygen for the period 2006–2015. Along 23° W between 6 and 14° N, oxygen decreased with a rate of −5.9 ± 3.5 µmol kg−1 decade−1 within the depth covering the deep oxycline (200–400 m), while below the OMZ core (400–1000 m) oxygen increased by 4.0 ± 1.6 µmol kg−1 decade−1 on average. The inclusion of these decadal oxygen trends in the recently estimated oxygen budget for the ETNA OMZ suggests a weakened ventilation of the upper 400 m, whereas the ventilation strengthened homogeneously below 400 m. The changed ventilation resulted in a shoaling of the ETNA OMZ of −0.03 ± 0.02 kg m−3 decade−1 in density space, which was only partly compensated by a deepening of isopycnal surfaces, thus pointing to a shoaling of the OMZ in depth space as well (−22 ± 17 m decade−1). Based on the improved oxygen budget, possible causes for the changed ventilation are analyzed and discussed. Largely ruling out other ventilation processes, the zonal advective oxygen supply stands out as the most probable budget term responsible for the decadal oxygen changes. |
format |
Article in Journal/Newspaper |
author |
Hahn, Johannes Brandt, Peter Schmidtko, Sunke Krahmann, Gerd |
spellingShingle |
Hahn, Johannes Brandt, Peter Schmidtko, Sunke Krahmann, Gerd Decadal oxygen change in the eastern tropical North Atlantic |
author_facet |
Hahn, Johannes Brandt, Peter Schmidtko, Sunke Krahmann, Gerd |
author_sort |
Hahn, Johannes |
title |
Decadal oxygen change in the eastern tropical North Atlantic |
title_short |
Decadal oxygen change in the eastern tropical North Atlantic |
title_full |
Decadal oxygen change in the eastern tropical North Atlantic |
title_fullStr |
Decadal oxygen change in the eastern tropical North Atlantic |
title_full_unstemmed |
Decadal oxygen change in the eastern tropical North Atlantic |
title_sort |
decadal oxygen change in the eastern tropical north atlantic |
publisher |
Copernicus Publications (EGU) |
publishDate |
2017 |
url |
https://oceanrep.geomar.de/id/eprint/35550/ https://oceanrep.geomar.de/id/eprint/35550/1/os-2016-102.pdf https://oceanrep.geomar.de/id/eprint/35550/7/os-13-551-2017.pdf https://doi.org/10.5194/os-13-551-2017 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://oceanrep.geomar.de/id/eprint/35550/1/os-2016-102.pdf https://oceanrep.geomar.de/id/eprint/35550/7/os-13-551-2017.pdf Hahn, J. , Brandt, P. , Schmidtko, S. and Krahmann, G. (2017) Decadal oxygen change in the eastern tropical North Atlantic. Open Access Ocean Science, 13 (4). pp. 551-576. DOI 10.5194/os-13-551-2017 <https://doi.org/10.5194/os-13-551-2017>. doi:10.5194/os-13-551-2017 |
op_rights |
cc_by_3.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/os-13-551-2017 |
container_title |
Ocean Science |
container_volume |
13 |
container_issue |
4 |
container_start_page |
551 |
op_container_end_page |
576 |
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1779317298446729216 |