Millennial-scale variations in sedimentary oxygenation in the western subtropical North Pacific and its links to North Atlantic climate
The deep-ocean carbon cycle, especially carbon sequestration and outgassing, is one of the mechanisms to explain variations in atmospheric CO 2 concentrations on millennial and orbital timescales. However, the potential role of subtropical North Pacific subsurface waters in modulating atmospheric CO...
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ftdoajarticles:oai:doaj.org/article:196f809848114f9b86440919f7106969 2023-05-15T17:36:18+02:00 Millennial-scale variations in sedimentary oxygenation in the western subtropical North Pacific and its links to North Atlantic climate J. Zou X. Shi A. Zhu S. Kandasamy X. Gong L. Lembke-Jene M.-T. Chen Y. Wu S. Ge Y. Liu X. Xue G. Lohmann R. Tiedemann 2020-02-01T00:00:00Z https://doi.org/10.5194/cp-16-387-2020 https://doaj.org/article/196f809848114f9b86440919f7106969 EN eng Copernicus Publications https://www.clim-past.net/16/387/2020/cp-16-387-2020.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-16-387-2020 1814-9324 1814-9332 https://doaj.org/article/196f809848114f9b86440919f7106969 Climate of the Past, Vol 16, Pp 387-407 (2020) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2020 ftdoajarticles https://doi.org/10.5194/cp-16-387-2020 2022-12-31T09:26:16Z The deep-ocean carbon cycle, especially carbon sequestration and outgassing, is one of the mechanisms to explain variations in atmospheric CO 2 concentrations on millennial and orbital timescales. However, the potential role of subtropical North Pacific subsurface waters in modulating atmospheric CO 2 levels on millennial timescales is poorly constrained. An increase in the respired CO 2 concentration in the glacial deep-ocean due to biological pump generally corresponds to deoxygenation in the ocean interior. This link thus offers a chance to study oceanic ventilation and coeval export productivity based on redox-controlled sedimentary geochemical parameters. Here, we investigate a suite of geochemical proxies in a sediment core from the Okinawa Trough to understand sedimentary oxygenation variations in the subtropical North Pacific over the last 50 000 years (50 ka). Our results suggest that enhanced mid-depth western subtropical North Pacific (WSTNP) sedimentary oxygenation occurred during cold intervals and after 8.5 ka, while oxygenation decreased during the Bölling-Alleröd (B/A) and Preboreal. The enhanced oxygenation during cold spells is linked to the North Pacific Intermediate Water (NPIW), while interglacial increase after 8.5 ka is linked to an intensification of the Kuroshio Current due to strengthened northeast trade winds over the tropics. The enhanced formation of the NPIW during Heinrich Stadial 1 (HS1) was likely driven by the perturbation of sea ice formation and sea surface salinity oscillations in the high-latitude North Pacific. The diminished sedimentary oxygenation during the B/A due to a decreased NPIW formation and enhanced export production, indicates an expansion of the oxygen minimum zone in the North Pacific and enhanced CO 2 sequestration at mid-depth waters, along with the termination of atmospheric CO 2 concentration increase. We attribute the millennial-scale changes to an intensified NPIW and enhanced abyss flushing during deglacial cold and warm intervals, respectively, closely ... Article in Journal/Newspaper North Atlantic Sea ice Directory of Open Access Journals: DOAJ Articles Pacific Climate of the Past 16 1 387 407 |
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ftdoajarticles |
language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
spellingShingle |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 J. Zou X. Shi A. Zhu S. Kandasamy X. Gong L. Lembke-Jene M.-T. Chen Y. Wu S. Ge Y. Liu X. Xue G. Lohmann R. Tiedemann Millennial-scale variations in sedimentary oxygenation in the western subtropical North Pacific and its links to North Atlantic climate |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
The deep-ocean carbon cycle, especially carbon sequestration and outgassing, is one of the mechanisms to explain variations in atmospheric CO 2 concentrations on millennial and orbital timescales. However, the potential role of subtropical North Pacific subsurface waters in modulating atmospheric CO 2 levels on millennial timescales is poorly constrained. An increase in the respired CO 2 concentration in the glacial deep-ocean due to biological pump generally corresponds to deoxygenation in the ocean interior. This link thus offers a chance to study oceanic ventilation and coeval export productivity based on redox-controlled sedimentary geochemical parameters. Here, we investigate a suite of geochemical proxies in a sediment core from the Okinawa Trough to understand sedimentary oxygenation variations in the subtropical North Pacific over the last 50 000 years (50 ka). Our results suggest that enhanced mid-depth western subtropical North Pacific (WSTNP) sedimentary oxygenation occurred during cold intervals and after 8.5 ka, while oxygenation decreased during the Bölling-Alleröd (B/A) and Preboreal. The enhanced oxygenation during cold spells is linked to the North Pacific Intermediate Water (NPIW), while interglacial increase after 8.5 ka is linked to an intensification of the Kuroshio Current due to strengthened northeast trade winds over the tropics. The enhanced formation of the NPIW during Heinrich Stadial 1 (HS1) was likely driven by the perturbation of sea ice formation and sea surface salinity oscillations in the high-latitude North Pacific. The diminished sedimentary oxygenation during the B/A due to a decreased NPIW formation and enhanced export production, indicates an expansion of the oxygen minimum zone in the North Pacific and enhanced CO 2 sequestration at mid-depth waters, along with the termination of atmospheric CO 2 concentration increase. We attribute the millennial-scale changes to an intensified NPIW and enhanced abyss flushing during deglacial cold and warm intervals, respectively, closely ... |
format |
Article in Journal/Newspaper |
author |
J. Zou X. Shi A. Zhu S. Kandasamy X. Gong L. Lembke-Jene M.-T. Chen Y. Wu S. Ge Y. Liu X. Xue G. Lohmann R. Tiedemann |
author_facet |
J. Zou X. Shi A. Zhu S. Kandasamy X. Gong L. Lembke-Jene M.-T. Chen Y. Wu S. Ge Y. Liu X. Xue G. Lohmann R. Tiedemann |
author_sort |
J. Zou |
title |
Millennial-scale variations in sedimentary oxygenation in the western subtropical North Pacific and its links to North Atlantic climate |
title_short |
Millennial-scale variations in sedimentary oxygenation in the western subtropical North Pacific and its links to North Atlantic climate |
title_full |
Millennial-scale variations in sedimentary oxygenation in the western subtropical North Pacific and its links to North Atlantic climate |
title_fullStr |
Millennial-scale variations in sedimentary oxygenation in the western subtropical North Pacific and its links to North Atlantic climate |
title_full_unstemmed |
Millennial-scale variations in sedimentary oxygenation in the western subtropical North Pacific and its links to North Atlantic climate |
title_sort |
millennial-scale variations in sedimentary oxygenation in the western subtropical north pacific and its links to north atlantic climate |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/cp-16-387-2020 https://doaj.org/article/196f809848114f9b86440919f7106969 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic Sea ice |
genre_facet |
North Atlantic Sea ice |
op_source |
Climate of the Past, Vol 16, Pp 387-407 (2020) |
op_relation |
https://www.clim-past.net/16/387/2020/cp-16-387-2020.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-16-387-2020 1814-9324 1814-9332 https://doaj.org/article/196f809848114f9b86440919f7106969 |
op_doi |
https://doi.org/10.5194/cp-16-387-2020 |
container_title |
Climate of the Past |
container_volume |
16 |
container_issue |
1 |
container_start_page |
387 |
op_container_end_page |
407 |
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1766135752821833728 |