气候变化领域集成服务门户(CCPortal): Reduced upwelling of nutrient and carbon-rich water in the subarctic Pacific during the Mid-Pleistocene Transition

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DOI	10.1016/j.palaeo.2020.109845
	Reduced upwelling of nutrient and carbon-rich water in the subarctic Pacific during the Mid-Pleistocene Transition
	Worne S.; Kender S.; Swann G.E.A.; Leng M.J.; Ravelo A.C.
发表日期	2020
ISSN	0031-0182
卷号	555
英文摘要	Reduction in atmospheric pCO2 has been hypothesised as a causal mechanism for the Mid-Pleistocene Transition (MPT), which saw global cooling and increased duration of glacials between 0.6 and 1.2 Ma. Sea ice-modulated high latitude upwelling and ocean-atmospheric CO2 flux is considered a potential mechanism for pCO2 decline, although there are no long-term nutrient upwelling records from high latitude regions to test this hypothesis. Using nitrogen isotopes and opal mass accumulation rates from 0 to 1.2 Ma, we calculate a continuous high resolution nutrient upwelling index for the Bering Sea and assess possible changes to regional CO2 fluxes and to the relative control of sea ice, sea level and glacial North Pacific Intermediate Water (GNPIW) on deep mixing and nutrient upwelling in the region. We find nutrient upwelling in the Bering Sea correlates with global ice volume and air temperature throughout the study interval. From ~1 Ma, and particularly during the 900 ka event, suppressed nutrient upwelling would have lowered oceanic fluxes of CO2 to the atmosphere supporting a reduction in global pCO2 during the MPT. This timing is consistent with a pronounced increase in sea ice during the early Pleistocene and restriction of flow through the Bering Strait during glacials after ~900 ka, both of which would have acted to suppress upwelling. We suggest that sea-level modulated GNPIW expansion during glacials after 900 ka was the dominant control on subarctic Pacific upwelling strength during the mid-late Pleistocene, while sea ice variability played a secondary role. © 2020
英文关键词	Bering Sea; CO2; MPT; Sea Ice; Upwelling index
语种	英语
scopus关键词	air temperature; atmosphere-ocean system; carbon dioxide; carbon flux; cooling; hypothesis testing; nitrogen isotope; Pleistocene; sea ice; upwelling; Bering Sea; Bering Strait; Pacific Ocean; Pacific Ocean (North)
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150417
作者单位	Centre for Environmental Geochemistry, School of Geography, University of Nottingham, Nottingham, NG7 2RD, United Kingdom; Camborne School of Mines, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, United Kingdom; National Environmental Isotope Facility, British Geological Survey, Keyworth, Nottingham, NG12 5GG, United Kingdom; Centre for Environmental Geochemistry, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, NE12 5RD, United Kingdom; University of California, Santa Cruz, CA 95064, United States
推荐引用方式 GB/T 7714	Worne S.,Kender S.,Swann G.E.A.,et al. Reduced upwelling of nutrient and carbon-rich water in the subarctic Pacific during the Mid-Pleistocene Transition[J],2020,555.
APA	Worne S.,Kender S.,Swann G.E.A.,Leng M.J.,&Ravelo A.C..(2020).Reduced upwelling of nutrient and carbon-rich water in the subarctic Pacific during the Mid-Pleistocene Transition.Palaeogeography, Palaeoclimatology, Palaeoecology,555.
MLA	Worne S.,et al."Reduced upwelling of nutrient and carbon-rich water in the subarctic Pacific during the Mid-Pleistocene Transition".Palaeogeography, Palaeoclimatology, Palaeoecology 555(2020).