气候变化领域集成服务门户(CCPortal): Subglacial Discharge and Its Down-Fjord Transformation in West Greenland Fjords With an Ice Mélange

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DOI	10.1029/2020JC016301
	Subglacial Discharge and Its Down-Fjord Transformation in West Greenland Fjords With an Ice Mélange
	Mortensen J.; Rysgaard S.; Bendtsen J.; Lennert K.; Kanzow T.; Lund H.; Meire L.
发表日期	2020
ISSN	21699275
卷号	125 期号:9
英文摘要	Buoyant freshwater released at depth from under Greenland's marine-terminating glaciers gives rise to vigorous buoyant discharge plumes adjacent to the termini. The water mass found down fjord formed by mixing of buoyant subglacial freshwater and ambient fjord water and subsequent modification by glacial ice melt in the ice mélange is referred to as subglacial water. It substantially affects both the physical and chemical properties of the fjords' marine environment. Despite the importance of this freshwater source, many uncertainties remain regarding its transformation and detection. Here we present observations close to a marine-terminating glacier in a fjord with substantial ice mélange and follow the down-fjord changes of the subglacial discharge plume. Heat brought to the surface by entrainment of warm ambient fjord water into the rising plume causes intense melting of the ice mélange close to the plume pool. This results in an increase of glacial ice melt fraction to total glacial meltwater from 1–2% in the plume pool to ~18% eleven kilometers down-fjord, with the largest increase being observed within the first few kilometers. Down-fjord of the ice mélange two temperature minima bound the layer containing subglacial water. The upper bound is linked to the adjacent ice mélange and down-fjord runoff sources, whereas the lower bound is linked to the stratification of the ambient water. We show that similar bounds can be observed in other marine-terminating glacier fjords along West Greenland that contain an ice mélange, suggesting that similar processes work in other fjords. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	climate change; ice mélange; plume pool; subglacial discharge plume; tidewater glacier fjords; water masses
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186692
作者单位	Greenland Climate Research Centre, Greenland Institute of Natural Resources, Nuuk, Greenland; Arctic Research Centre, Department of Bioscience, Aarhus University, Aarhus, Denmark; Centre for Earth Observation Science, CHR Faculty of Environment Earth and Resources, University of Manitoba, Winnipeg, MB, Canada; Norwegian Institute for Water Research, Niva Denmark, Copenhagen, Denmark; The Arctic University of Norway, University of Tromsø, Tromsø, Norway; Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany; Bremen University, Bremen, Germany; Greenland Institute of Natural Resources, Nuuk, Greenland; Department of Estuarine and Delta Systems, Royal Netherlands Institute for Sea Research and Utrecht University, Yerseke, Netherlands
推荐引用方式 GB/T 7714	Mortensen J.,Rysgaard S.,Bendtsen J.,et al. Subglacial Discharge and Its Down-Fjord Transformation in West Greenland Fjords With an Ice Mélange[J],2020,125(9).
APA	Mortensen J..,Rysgaard S..,Bendtsen J..,Lennert K..,Kanzow T..,...&Meire L..(2020).Subglacial Discharge and Its Down-Fjord Transformation in West Greenland Fjords With an Ice Mélange.Journal of Geophysical Research: Oceans,125(9).
MLA	Mortensen J.,et al."Subglacial Discharge and Its Down-Fjord Transformation in West Greenland Fjords With an Ice Mélange".Journal of Geophysical Research: Oceans 125.9(2020).