Journal cover Journal topic
The Cryosphere An interactive open-access journal of the European Geosciences Union
The Cryosphere, 9, 2135-2148, 2015
http://www.the-cryosphere.net/9/2135/2015/
doi:10.5194/tc-9-2135-2015
© Author(s) 2015. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
18 Nov 2015
From Doktor Kurowski's Schneegrenze to our modern glacier equilibrium line altitude (ELA)
R. J. Braithwaite School of Environment, Education and Development (SEED), University of Manchester, Manchester, UK
Abstract. Translated into modern terminology, Kurowski suggested in 1891 that the equilibrium line altitude (ELA) of a glacier is equal to the mean altitude of the glacier when the whole glacier is in balance between accumulation and ablation. Kurowski's method has been widely misunderstood, partly due to inappropriate use of statistical terminology by later workers, and has only been tested by Braithwaite and Müller in a 1980 paper (for 32 glaciers). I now compare Kurowski's mean altitude with balanced-budget ELA calculated for 103 present-day glaciers with measured surface mass-balance data. Kurowski's mean altitude is significantly higher (at 95 % level) than balanced-budget ELA for 19 outlet and 42 valley glaciers, but not significantly higher for 34 mountain glaciers. The error in Kurowski mean altitude as a predictor of balanced-budget ELA might be due to generally lower balance gradients in accumulation areas compared with ablation areas for many glaciers, as suggested by several workers, but some glaciers have higher gradients, presumably due to precipitation increase with altitude. The relatively close agreement between balanced-budget ELA and mean altitude for mountain glaciers (mean error – 8 m with standard deviation 59 m) may reflect smaller altitude ranges for these glaciers such that there is less room for effects of different balance gradients to manifest themselves.

Citation: Braithwaite, R. J.: From Doktor Kurowski's Schneegrenze to our modern glacier equilibrium line altitude (ELA), The Cryosphere, 9, 2135-2148, doi:10.5194/tc-9-2135-2015, 2015.
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Short summary
Kurowski suggested in 1891 that ELA is equal to the mean altitude of the glacier when the glacier is in balance. I compare mean altitude with balanced-budget ELA for 103 modern glaciers. Kurowski’s mean altitude is significantly higher (at 95% level) than balanced-budget ELA for 19 outlet and 42 valley glaciers, but not significantly higher for 34 mountain glaciers. The error in Kurowski mean altitude as a predictor of balanced budget might be due to non-linearity in balance gradients.
Kurowski suggested in 1891 that ELA is equal to the mean altitude of the glacier when the...
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