Effects of Climatic Perturbations on the Surface-Ablation Regime of the Greenland Ice Sheet, West Greenland

Abstract The shift of the equilibrium-line altitude by climatic perturbations of air temperature δ T a , absolute humidity δρ v , cloudiness δ w and annual accumulation 6c in West Greenland (EGIG profile) is analyzed by heat-balance modelling. The perturbations δ T a = +1 K, δρ v = +0.25 g m −3 , δ...

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Bibliographic Details
Published in:Journal of Glaciology
Main Author: Ambach, W.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1989
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Online Access:http://dx.doi.org/10.1017/s0022143000009229
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000009229
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Summary:Abstract The shift of the equilibrium-line altitude by climatic perturbations of air temperature δ T a , absolute humidity δρ v , cloudiness δ w and annual accumulation 6c in West Greenland (EGIG profile) is analyzed by heat-balance modelling. The perturbations δ T a = +1 K, δρ v = +0.25 g m −3 , δ c = +50 kg m −2 result in a shift of the equilibrium-line altitude of 87.5, 9.8, and −24.3 m, respectively, while perturbations in cloudiness are negligible. The most important influence originates from changing air temperature, as air temperature affects daily heat-flux density of melt and duration of the ablation period. In regimes with negative values of the gradient of annual accumulation, the shift of the equilibrium line is enhanced.