How sensitive are mountain glaciers to climate change? Insights from a block model

ABSTRACT Simple models of glacier volume evolution are important in understanding features of glacier response to climate change, due to the scarcity of data adequate for running more complex models on a global scale. Two quantities of interest in a glacier's response to climate changes are its...

Full description

Bibliographic Details
Published in:Journal of Glaciology
Main Authors: BACH, EVIATAR, RADIĆ, VALENTINA, SCHOOF, CHRISTIAN
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 2018
Subjects:
Ela
Online Access:http://dx.doi.org/10.1017/jog.2018.15
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143018000151
Description
Summary:ABSTRACT Simple models of glacier volume evolution are important in understanding features of glacier response to climate change, due to the scarcity of data adequate for running more complex models on a global scale. Two quantities of interest in a glacier's response to climate changes are its response time and its volume sensitivity to changes in the equilibrium line altitude (ELA). We derive a simplified, computationally inexpensive model of glacier volume evolution based on a block model with volume–area–length scaling. After analyzing its steady-state properties, we apply the model to each mountain glacier worldwide and estimate regionally differentiated response times and sensitivities to ELA changes. We use a statistical method from the family of global sensitivity analysis methods to determine the glacier quantities, geometric and climatic, that most influence the model output. The response time is dominated by the climatic setting reflected in the mass-balance gradient in the ablation zone, followed by the surface slope, while volume sensitivity is mainly affected by glacier size, followed by the surface slope.