气候变化领域集成服务门户(CCPortal): The Contribution of Methane Photoproduction to the Oceanic Methane Paradox

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DOI	10.1029/2020GL088362
	The Contribution of Methane Photoproduction to the Oceanic Methane Paradox
	Li Y.; Fichot C.G.; Geng L.; Scarratt M.G.; Xie H.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:14
英文摘要	Although methanogenesis is considered a strictly anaerobic process, oxygen-replete surface open-ocean waters are usually supersaturated with methane (CH4), a phenomenon termed the oceanic methane paradox. Here, we report that abiotic methane photoproduction from chromophoric dissolved organic matter (CDOM) significantly contributes to this paradox. Methane photoproduction was observed during solar-simulated irradiations of various waters collected along the land-ocean continuum. Methane photoproduction rates decreased seaward, whereas its relative production efficiency and the methane-to-carbon-monoxide (CO) photoproduction ratio (ΔCH4/ΔCO) both followed a reversed trend. Remote-sensing modeling incorporating a ΔCH4/ΔCO–CDOM absorption relationship yielded an annual methane photoproduction of 118 Gg for the global open ocean, accounting for 20–60% of the open-ocean methane efflux and being of comparable magnitude to the upper-ocean methane microbial-oxidation sink. The photodegradation of CDOM thus plays an important role in maintaining supersaturated methane concentrations in the oxygenated upper ocean and in sustaining oceanic methane emissions to the atmosphere. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Carbon monoxide; Oceanography; Remote sensing; Upper atmosphere; Anaerobic process; Chromophoric dissolved organic matter; Global open ocean; Methane concentrations; Methane emissions; Microbial oxidation; Production efficiency; Remote sensing models; Methane; air-sea interaction; anoxic conditions; dissolved organic matter; methane; methanogenesis; microbial activity; open ocean; oxygenation; photochemistry; photodegradation; saturated medium; solar radiation; upper ocean
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/170122
作者单位	Institut des sciences de la mer de Rimouski, Université du Québec à Rimouski, Rimouski, QC, Canada; Department of Earth and Environment, Boston University, Boston, MA, United States; Guangzhou Marine Geological Survey, China Geological Survey, Guangzhou, China; College of Marine Science and Technology, China University of Geosciences (Wuhan), Wuhan, China; Department of Fisheries and Oceans Canada, Maurice-Lamontagne Institute, Mont-Joli, QC, Canada
推荐引用方式 GB/T 7714	Li Y.,Fichot C.G.,Geng L.,et al. The Contribution of Methane Photoproduction to the Oceanic Methane Paradox[J],2020,47(14).
APA	Li Y.,Fichot C.G.,Geng L.,Scarratt M.G.,&Xie H..(2020).The Contribution of Methane Photoproduction to the Oceanic Methane Paradox.Geophysical Research Letters,47(14).
MLA	Li Y.,et al."The Contribution of Methane Photoproduction to the Oceanic Methane Paradox".Geophysical Research Letters 47.14(2020).