DOI: 10.1073/pnas.1714754115
论文题名: Rapid shift and millennial-scale variations in Holocene North pacific intermediate water ventilation
作者: Lembke-Jene L. ; Tiedemann R. ; Nürnberg D. ; Gong X. ; Lohmann G.
刊名: Proceedings of the National Academy of Sciences of the United States of America
ISSN: 0027-8424
出版年: 2018
卷: 115, 期: 21 起始页码: 5365
结束页码: 5370
语种: 英语
英文关键词: Holocene
; Intermediate water
; North Pacific
; Oxygen minimum zone
; Stable isotopes
Scopus关键词: Article
; biogeochemistry
; carbon storage
; controlled study
; Holocene
; latitude
; nutrient concentration
; ocean environment
; oxygenation
; paleoceanography
; priority journal
; sea ice
; source sink relationship
; water temperature
英文摘要: The Pacific hosts the largest oxygen minimum zones (OMZs) in the world ocean, which are thought to intensify and expand under future climate change, with significant consequences for marine ecosystems, biogeochemical cycles, and fisheries. At present, no deep ventilation occurs in the North Pacific due to a persistent halocline, but relatively better-oxygenated subsurface North Pacific Intermediate Water (NPIW) mitigates OMZ development in lower latitudes. Over the past decades, instrumental data show decreasing oxygenation in NPIW; however, long-term variations in middepth ventilation are potentially large, obscuring anthropogenic influences against millennial-scale natural background shifts. Here, we use paleoceanographic proxy evidence from the Okhotsk Sea, the foremost North Pacific ventilation region, to show that its modern oxygenated pattern is a relatively recent feature, with little to no ventilation before six thousand years ago, constituting an apparent Early–Middle Holocene (EMH) threshold or “tipping point.” Complementary paleomodeling results likewise indicate a warmer, saltier EMH NPIW, different from its modern conditions. During the EMH, the Okhotsk Sea switched from a modern oxygenation source to a sink, through a combination of sea ice loss, higher water temperatures, and remineralization rates, inhibiting ventilation. We estimate a strongly decreased EMH NPIW oxygenation of ∼30 to 50%, and increased middepth Pacific nutrient concentrations and carbon storage. Our results (i) imply that under past or future warmer-than-present conditions, oceanic biogeochemical feedback mechanisms may change or even switch direction, and (ii) provide constraints on the high-latitude North Pacific’s influence on mesopelagic ventilation dynamics, with consequences for large oceanic regions. © 2018 National Academy of Sciences. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/163707
Appears in Collections: 气候变化与战略
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作者单位: Lembke-Jene, L., Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, 27570, Germany; Tiedemann, R., Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, 27570, Germany; Nürnberg, D., GEOMAR Helmholtz-Zentrum fürOzeanforschung Kiel, Kiel, 24148, Germany; Gong, X., Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, 27570, Germany; Lohmann, G., Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, 27570, Germany
Recommended Citation:
Lembke-Jene L.,Tiedemann R.,Nürnberg D.,et al. Rapid shift and millennial-scale variations in Holocene North pacific intermediate water ventilation[J]. Proceedings of the National Academy of Sciences of the United States of America,2018-01-01,115(21)