气候变化领域集成服务门户(CCPortal): Methane pathways in winter ice of a thermokarst lake-lagoon-coastal water transect in north Siberia

CCPortal

DOI	10.5194/tc-15-1607-2021
	Methane pathways in winter ice of a thermokarst lake-lagoon-coastal water transect in north Siberia
	Spangenberg I.; Paul Overduin P.; Damm E.; Bussmann I.; Meyer H.; Liebner S.; Angelopoulos M.; K. Biskaborn B.; N. Grigoriev M.; Grosse G.
发表日期	2021
ISSN	19940416
起始页码	1607
结束页码	1625
卷号	15 期号:3
英文摘要	The thermokarst lakes of permafrost regions play a major role in the global carbon cycle. These lakes are sources of methane to the atmosphere although the methane flux is restricted by an ice cover for most of the year. How methane concentrations and fluxes in these waters are affected by the presence of an ice cover is poorly understood. To relate water body morphology, ice formation and methane to each other, we studied the ice of three different water bodies in locations typical of the transition of permafrost from land to ocean in a continuous permafrost coastal region in Siberia. In total, 11 ice cores were analyzed as records of the freezing process and methane composition during the winter season. The three water bodies differed in terms of connectivity to the sea, which affected fall freezing. The first was a bay underlain by submarine permafrost (Tiksi Bay, BY), the second a shallow thermokarst lagoon cut off from the sea in winter (Polar Fox Lagoon, LG) and the third a land-locked freshwater thermokarst lake (Goltsovoye Lake, LK). Ice on all water bodies was mostly methane-supersaturated with respect to atmospheric equilibrium concentration, except for three cores from the isolated lake. In the isolated thermokarst lake, ebullition from actively thawing basin slopes resulted in the localized integration of methane into winter ice. Stable 13CCH4 isotope signatures indicated that methane in the lagoon ice was oxidized to concentrations close to or below the calculated atmospheric equilibrium concentration. Increasing salinity during winter freezing led to a micro-environment on the lower ice surface where methane oxidation occurred and the lagoon ice functioned as a methane sink. In contrast, the ice of the coastal marine environment was slightly supersaturated with methane, consistent with the brackish water below. Our interdisciplinary process study shows how water body morphology affects ice formation which mitigates methane fluxes to the atmosphere. © 2021 Copernicus GmbH. All rights reserved.
英文关键词	coastal water; fluviolacustrine deposit; ice core; ice field; lacustrine environment; lagoon; methane; oxidation; permafrost; snowmelt; thermokarst; Siberia; Vulpes lagopus
语种	英语
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202432
作者单位	University of Potsdam, Institute of Environmental Science and Geography, Potsdam, Germany; Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Potsdam, Germany; GFZ German Research Centre for Geosciences, Section Geomicrobiology, Potsdam, Germany; University of Potsdam, Institute of Biochemistry and Biology, Potsdam, Germany; University of Potsdam, Institute of Geosciences, Potsdam, Germany; Mel'nikov Permafrost Institute, Siberian Branch, Russian Academy of Sciences, Yakutsk, Russian Federation
推荐引用方式 GB/T 7714	Spangenberg I.,Paul Overduin P.,Damm E.,et al. Methane pathways in winter ice of a thermokarst lake-lagoon-coastal water transect in north Siberia[J],2021,15(3).
APA	Spangenberg I..,Paul Overduin P..,Damm E..,Bussmann I..,Meyer H..,...&Grosse G..(2021).Methane pathways in winter ice of a thermokarst lake-lagoon-coastal water transect in north Siberia.Cryosphere,15(3).
MLA	Spangenberg I.,et al."Methane pathways in winter ice of a thermokarst lake-lagoon-coastal water transect in north Siberia".Cryosphere 15.3(2021).