气候变化领域集成服务门户(CCPortal): Heterogeneous CO2and CH4content of glacial meltwater from the Greenland Ice Sheet and implications for subglacial carbon processes

CCPortal

DOI	10.5194/tc-15-1627-2021
	Heterogeneous CO2and CH4content of glacial meltwater from the Greenland Ice Sheet and implications for subglacial carbon processes
	Pain A.J.; Martin J.B.; Martin E.E.; Rennermalm A.K.; Rahman S.
发表日期	2021
ISSN	19940416
起始页码	1627
结束页码	1644
卷号	15 期号:3
英文摘要	Accelerated melting of the Greenland Ice Sheet has increased freshwater delivery to the Arctic Ocean and amplified the need to understand the impact of Greenland Ice Sheet meltwater on Arctic greenhouse gas budgets. We evaluate subglacial discharge from the Greenland Ice Sheet for carbon dioxide (CO2) and methane (CH4) concentrations and δ13C values and use geochemical models to evaluate subglacial CH4and CO2sources and sinks. We compare discharge from southwest (a sub-catchment of the Isunnguata Glacier, sub-Isunnguata, and the Russell Glacier) and southern Greenland (Kiattut Sermiat). Meltwater CH4concentrations vary by orders of magnitude between sites and are saturated with respect to atmospheric concentrations at Kiattut Sermiat. In contrast, meltwaters from southwest sites are supersaturated, even though oxidation reduces CH4concentrations by up to 50% during periods of low discharge. CO2concentrations range from supersaturated at sub-Isunnguata to undersaturated at Kiattut Sermiat. CO2is consumed by mineral weathering throughout the melt season at all sites; however, differences in the magnitude of subglacial CO2sources result in meltwaters that are either sources or sinks of atmospheric CO2. At the sub-Isunnguata site, the predominant source of CO2is organic matter (OM) remineralization. However, multiple or heterogeneous subglacial CO2sources maintain atmospheric CO2concentrations at Russell but not at Kiattut Sermiat, where CO2is undersaturated. These results highlight a previously unrecognized degree of heterogeneity in greenhouse gas dynamics under the Greenland Ice Sheet. Future work should constrain the extent and controls of heterogeneity to improve our understanding of the impact of Greenland Ice Sheet melt on Arctic greenhouse gas budgets, as well as the role of continental ice sheets in greenhouse gas variations over glacial interglacial timescales. © 2019 EDP Sciences. All rights reserved.
英文关键词	carbon dioxide; discharge; greenhouse gas; heterogeneity; interglacial; meltwater; methane; organic matter; oxidation; weathering; Arctic; Arctic Ocean; Greenland; Greenland Ice Sheet; Russell Glacier
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/202400
作者单位	Department of Geological Sciences, University of Florida, Gainesville, FL 32611, United States; Department of Geography, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, United States; University of Maryland Center for Environmental Science, Horn Point Lab, Cambridge, MD 21613, United States; Department of Marine Science, University of Southern Mississippi, Stennis Space CenterMS 39529, United States
推荐引用方式 GB/T 7714	Pain A.J.,Martin J.B.,Martin E.E.,et al. Heterogeneous CO2and CH4content of glacial meltwater from the Greenland Ice Sheet and implications for subglacial carbon processes[J],2021,15(3).
APA	Pain A.J.,Martin J.B.,Martin E.E.,Rennermalm A.K.,&Rahman S..(2021).Heterogeneous CO2and CH4content of glacial meltwater from the Greenland Ice Sheet and implications for subglacial carbon processes.Cryosphere,15(3).
MLA	Pain A.J.,et al."Heterogeneous CO2and CH4content of glacial meltwater from the Greenland Ice Sheet and implications for subglacial carbon processes".Cryosphere 15.3(2021).