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标题：Historical ablation rates on south-east Greenland glaciers measured in the 1933 warm summer
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作者：Bent Hasholt ; Dirk van As ; Niels Tvis Knudsen 等
期刊名称：Polar Research
印刷版ISSN：1751-8369
出版年度：2016
卷号：35
期号：1
页码：28858
DOI：10.3402/polar.v35.28858
语种：English
出版社：Co-Action Publishing
摘要：Bent Hasholt ^a^* , Dirk van As ^b & Niels Tvis Knudsen ^c ^a Department of Geosciences and Natural Resource Management University of Copenhagen , Øster Voldgade 10, DK-1350 Copenhagen, Denmark ^b Department of Glaciology and Climate Geological Survey of Denmark and Greenland , Øster Voldgade 10, DK-1350 Copenhagen, Denmark ^c Department of Geoscience Aarhus University , Høegh-Guldbergs Gade 2, DK-8000 Aarhus, Denmark Correspondence Bent Hasholt, Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen, Denmark. E-mail: [email protected] Ice ablation rates measured on four glaciers in south-east Greenland in summer 1933 are recovered from an old field book of geologist K. Milthers. These unpublished ablation data are among the first measured in Greenland and were obtained during a warm period comparable to that of recent years. Ablation rates of up to 45 mm ice eq. d⁻¹ were observed. Using the Tasiilaq meteorological record, we calculate degree-day factors of ca. 3–5 mm ice eq. d⁻¹°C⁻¹. Comparing these results with 1996–2012 observations at one of Milthers’ glaciers (Mittivakkat), we find that ablation rates and degree-day factors are significantly higher (61±50%) in recent years. We speculate this to be due to a reduction in surface albedo, and perhaps the retreat of the glaciers out of the cold maritime inversion layer. Our findings suggest that using a temperature-index method that assumes constant degree-day factors may produce inaccurate long-term ablation estimates for south-east Greenland glaciers, further emphasizing the value of the rare 1933 measurements for validation of ablation models.
关键词：Surface mass balance ; positive degree-days ; climate change ; Mittivakkat Glacier ; Milthers ; 7th Thule Expedition.