气候变化领域集成服务门户(CCPortal): Distinct air–water gas exchange regimes in low- and high-energy streams

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DOI	10.1038/s41561-019-0324-8
	Distinct air–water gas exchange regimes in low- and high-energy streams
	Ulseth A.J.; Hall R.O.; Jr.; Boix Canadell M.; Madinger H.L.; Niayifar A.; Battin T.J.
发表日期	2019
ISSN	17520894
卷号	12 期号:4
英文摘要	Gas exchange across the air–water interface drives the flux of climate-relevant gases and is critical for biogeochemical processes in aquatic ecosystems. Despite the presence of mountain streams worldwide, we lack basic understanding of gas exchange through their turbulent surfaces, making global estimates of outgassing from streams and rivers difficult to constrain. Here we combine new estimates of gas transfer velocities from tracer gas additions in mountain streams with published data to cover streams differing in geomorphology and hydraulics. We find two different scaling relationships between the turbulence-induced energy dissipation rate and gas transfer velocity for low- and high-channel slope streams, indicating that gas exchange in streams exists in two states. We suggest that turbulent diffusion drives gas transfer velocity in low-energy streams; whereas turbulence entrains air bubbles in high-energy streams, and the resulting bubble-mediated gas exchange accelerates with energy dissipation rate. Gas transfer velocities in the high-energy streams are among the highest reported. Our findings offer a framework to include mountain streams in future estimates of gas fluxes from streams and rivers at the global scale. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.
语种	英语
scopus关键词	air bubble; air-water interaction; aquatic ecosystem; energy dissipation; flux measurement; gas exchange; geomorphology; mountain stream; turbulence; turbulent diffusion
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/124683
作者单位	Stream Biofilm and Ecosystem Research Laboratory, School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale Lausanne, Lausanne, Switzerland; Flathead Lake Biological Station, University of Montana, Polson, MT, United States; Program in Ecology and Department of Zoology and Physiology, University of Wyoming, Laramie, WY, United States; Department of Biological Sciences, Sam Houston State University, Huntsville, TX, United States; Department of Life & Earth Sciences, Concordia University Wisconsin, Mequon, WI, United States
推荐引用方式 GB/T 7714	Ulseth A.J.,Hall R.O.,Jr.,等. Distinct air–water gas exchange regimes in low- and high-energy streams[J],2019,12(4).
APA	Ulseth A.J..,Hall R.O..,Jr..,Boix Canadell M..,Madinger H.L..,...&Battin T.J..(2019).Distinct air–water gas exchange regimes in low- and high-energy streams.Nature Geoscience,12(4).
MLA	Ulseth A.J.,et al."Distinct air–water gas exchange regimes in low- and high-energy streams".Nature Geoscience 12.4(2019).