Geologic Publications for Mount Rainier

Analysis of scaling methods in deriving future volume evolutions of valley glaciers

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Author(s): Valentia Radic, Regine Hock, Johannes Oerlemans

Category: PUBLICATION
Document Type:
Publisher: Journal of Glaciology
Published Year: 2008
Volume: 54
Number: 187
Pages: 601 to 612
DOI Identifier: 10.3189/002214308786570809
ISBN Identifier:
Keywords:

Abstract:
Volume–area scaling is a common tool for deriving future volume evolutions of valley glaciers and their contribution to sea-level rise. We analyze the performance of scaling relationships for deriving volume projections in comparison to projections from a one-dimensional ice-flow model. The model is calibrated for six glaciers (Nigardsbreen, Rhonegletscher, South Cascade Glacier, Sofiyskiy glacier, midre Lovénbreen and Abramov glacier). Volume evolutions forced by different hypothetical mass-balance perturbations are compared with those obtained from volume–area (V-A), volume–length (V-L) and volume–area–length (V-A-L) scaling. Results show that the scaling methods mostly underestimate the volume losses predicted by the ice-flow model, up to 47% for V-A scaling and up to 18% for V-L scaling by the end of the 100 year simulation period. In general, V-L scaling produces closer simulations of volume evolutions derived from the ice-flow model, suggesting that V-L scaling may be a better approach for deriving volume projections than V-A scaling. Sensitivity experiments show that the initial volumes and volume evolutions are highly sensitive to the choice of the scaling constants, yielding both over- and underestimates. However, when normalized by initial volume, volume evolutions are relatively insensitive to the choice of scaling constants, especially in the V-L scaling. The 100 year volume projections differ within 10% of initial volume when the V-A scaling exponent commonly assumed, γ = 1.375, is varied by −30% to +45% (γ = [0.95, 2.00]) and the V-L scaling exponent, q = 2.2, is varied by −30% to +45% (q = [1.52, 3.20]). This is encouraging for the use of scaling methods in glacier volume projections, particularly since scaling exponents may vary between glaciers and the scaling constants are generally unknown.

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In Text Citation:
Radic and others (2008) or (Radic et al., 2008)

References Citation:
Radic, V., R. Hock, and J. Oerlemans, 2008, Analysis of scaling methods in deriving future volume evolutions of valley glaciers: Journal of Glaciology, Vol. 54, No. 187, pp. 601-612, doi: 10.3189/002214308786570809.