气候变化领域集成服务门户(CCPortal): Evolution of the firn pack of Kaskawulsh Glacier, Yukon: Meltwater effects, densification, and the development of a perennial firn aquifer

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DOI	10.5194/tc-15-2021-2021
	Evolution of the firn pack of Kaskawulsh Glacier, Yukon: Meltwater effects, densification, and the development of a perennial firn aquifer
	Ochwat N.E.; Marshall S.J.; Moorman B.J.; Criscitiello A.S.; Copland L.
发表日期	2021
ISSN	19940416
起始页码	2021
结束页码	2040
卷号	15 期号:4
英文摘要	In spring 2018, two firn cores (21 and 36 m in length) were extracted from the accumulation zone of Kaskawulsh Glacier, St. Elias Mountains, Yukon. The cores were analyzed for ice layer stratigraphy and density and compared against historical measurements made in 1964 and 2006. Deep meltwater percolation and refreezing events were evident in the cores, with a total ice content of >2.33±0.26< m in the 36 m core and liquid water discovered below a depth of 34.5 m. Together with the observed ice content, surface energy balance and firn modelling indicate that Kaskawulsh Glacier firn retained about 86 % of its meltwater in the years 2005-2017. For an average surface ablation of 0.38 m w.e. yr>-1< over this period, an estimated 0.28 m w.e. yr>-1< refroze in the firn, 0.05 m w.e. yr>-1< was retained as liquid water, and 0.05 m w.e. yr>-1< drained or ran off. The refrozen meltwater is associated with a surface lowering of >0.73±0.23< m between 2005 and 2017 (i.e., surface drawdown that has no associated mass loss). The firn has become denser and more ice-rich since the 1960s and contains a perennial firn aquifer (PFA), which may have developed over the past decade. This illustrates how firn may be evolving in response to climate change in the St. Elias Mountains, provides firn density information required for geodetic mass balance calculations, and is the first documented PFA in the Yukon-Alaska region. © 2021 BMJ Publishing Group. All rights reserved.
英文关键词	ablation; aquifer; drawdown; energy balance; firn; geodetic network; meltwater; surface energy; Alaska; Canada; Kaskawulsh Glacier; Saint Elias Mountains; St Elias Mountains; United States; Yukon Territory
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/202396
作者单位	Department of Geography, University of Calgary, Calgary, Alberta T2N 1N4, Canada; Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, 80309, United States; Environment and Climate Change Canada, Gatineau, Quebec K1A 0H3, Canada; Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, T6G 2R3, Canada; Department of Geography, Environment and Geomatics, University of Ottawa, Ottawa, ON K1N 6N5, Canada
推荐引用方式 GB/T 7714	Ochwat N.E.,Marshall S.J.,Moorman B.J.,et al. Evolution of the firn pack of Kaskawulsh Glacier, Yukon: Meltwater effects, densification, and the development of a perennial firn aquifer[J],2021,15(4).
APA	Ochwat N.E.,Marshall S.J.,Moorman B.J.,Criscitiello A.S.,&Copland L..(2021).Evolution of the firn pack of Kaskawulsh Glacier, Yukon: Meltwater effects, densification, and the development of a perennial firn aquifer.Cryosphere,15(4).
MLA	Ochwat N.E.,et al."Evolution of the firn pack of Kaskawulsh Glacier, Yukon: Meltwater effects, densification, and the development of a perennial firn aquifer".Cryosphere 15.4(2021).