气候变化领域集成服务门户(CCPortal): Glacial deep ocean deoxygenation driven by biologically mediated air

CCPortal

DOI	10.1038/s41561-020-00667-z
	Glacial deep ocean deoxygenation driven by biologically mediated air–sea disequilibrium
	Cliff E.; Khatiwala S.; Schmittner A.
发表日期	2021
ISSN	17520894
起始页码	43
结束页码	50
卷号	14 期号:1
英文摘要	Deep ocean deoxygenation inferred from proxies has been used to support the hypothesis that a lower atmospheric carbon dioxide during glacial times was due to an increase in the strength of the ocean’s biological pump. This relies on the assumption that surface ocean oxygen (O2) is equilibrated with the atmosphere such that any O2 deficiency observed in deep waters is a result of organic matter respiration, which consumes O2 and produces dissolved inorganic carbon. However, this assumption has been shown to be imperfect because of disequilibrium. Here we used an Earth system model tuned to a suite of observations, which reproduces the pattern of glacial-to-Holocene oxygenation change seen in proxy data, to show that disequilibrium plays an important role in glacial deep ocean deoxygenation. Using a novel decomposition method to track O2, we found a whole-ocean loss of 33 Pmol O2 from the preindustrial to the Last Glacial Maximum despite a 27 Pmol gain from the increased solubility due to cooler temperatures. This loss was driven by a biologically mediated O2 disequilibrium, which contributed 10% of the reduction of the O2 inventory from the solubility equilibrium in the preindustrial compared with 27% during the Last Glacial Maximum. Sea ice and iron fertilization were found to be the largest contributors to the Last Glacial Maximum deoxygenation, which occurs despite overall reduced production and respiration of organic matter in the glacial ocean. Our results challenge the notion that deep ocean glacial deoxygenation was caused by a stronger biological pump or more sluggish circulation, and instead highlight the importance and previously underappreciated role of O2 disequilibrium. © 2021, The Author(s), under exclusive licence to Springer Nature Limited.
英文关键词	air-sea interaction; biological pump; carbon dioxide; climate modeling; deep water; dissolved inorganic carbon; global ocean; Holocene; Last Glacial Maximum; organic matter; respiration
语种	英语
来源期刊	Nature Geoscience
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/206878
作者单位	Department of Earth Sciences, University of Oxford, Oxford, United Kingdom; College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, United States
推荐引用方式 GB/T 7714	Cliff E.,Khatiwala S.,Schmittner A.. Glacial deep ocean deoxygenation driven by biologically mediated air–sea disequilibrium[J],2021,14(1).
APA	Cliff E.,Khatiwala S.,&Schmittner A..(2021).Glacial deep ocean deoxygenation driven by biologically mediated air–sea disequilibrium.Nature Geoscience,14(1).
MLA	Cliff E.,et al."Glacial deep ocean deoxygenation driven by biologically mediated air–sea disequilibrium".Nature Geoscience 14.1(2021).