DOI: 10.5194/tc-15-1607-2021
论文题名: Methane pathways in winter ice of a thermokarst lake-lagoon-coastal water transect in north Siberia
作者: Spangenberg I. ; Paul Overduin P. ; Damm E. ; Bussmann I. ; Meyer H. ; Liebner S. ; Angelopoulos M. ; K. Biskaborn B. ; N. Grigoriev M. ; Grosse G.
刊名: Cryosphere
ISSN: 19940416
出版年: 2021
卷: 15, 期: 3 起始页码: 1607
结束页码: 1625
语种: 英语
英文关键词: coastal water
; fluviolacustrine deposit
; ice core
; ice field
; lacustrine environment
; lagoon
; methane
; oxidation
; permafrost
; snowmelt
; thermokarst
; Siberia
; Vulpes lagopus
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164810
Appears in Collections: 气候变化与战略
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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
Recommended Citation:
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]. Cryosphere,2021-01-01,15(3)