Modelling the response of glaciers to climate warming

Abstract

Dynamic ice-flow models for 12 glaciers and ice caps have been forced with various climate change scenarios. The volume of this sample spans three orders of magnitude. Six climate scenarios were considered: from 1990 onwards linear warming rates of 0.01, 0.02 and 0.04 K a\, with and without concurrent changes in precipitation. The models, calibrated against the historic record of glacier length where possible, were integrated until 2100. The differences in individual glacier responses are very large. No straightforward relationship between glacier size and fractional change of ice volume emerges for any given climate scenario. The hypsometry of individual glaciers and ice caps plays an important role in their response, thus making it difficult to generalize results. For a warming rate of 0.04 K a\, without increase in precipitation, results indicate that few glaciers would survive until 2100. On the other hand, if the warming rate were to be limited to 0.01 K a\ with an increase in precipitation of 10% per degree warming, we predict that overall loss would be restricted to 10 to 20% of the 1990 volume.

An iterative inverse method to estimate basal topography and initialize ice flow models

“…Proper initialization of ice flow models should result in an ice geometry and thermodynamic state at the start of a prognostic experiment, which is consistent with the history of the surface climate forcing. The relevance of accurate initialization has been stressed by, for example, Oerlemans et al (1998), Huybrechts and de Wolde (1999) and Huss et al (2008).…”

Application of Surface Matching for Improved Measurements of Historic Glacier Volume Change in the Antarctic Peninsula

“…However, airborne and satellite remote sensing offers an alternative tool for mapping of inaccessible areas. In particular, it has been noted that high-resolution satellite imagery, together with digital elevation models (DEM) derived from such imagery are well suited for the monitoring of glaciers (Oerlemans, 1998). In order to facilitate change analysis over extended time periods, a combination of historical and present-day stereo-imagery is ideal.…”

A review of topographic controls on moraine distribution

“…Sedimentological and morphometric analyses of moraines provide information about former glacier flow dynamics, thermal regime, and debris content (amongst other factors) (see Boulton, 1986;Lukas, 2005;Evans, 2009), but moraines are most commonly used simply as indicators of former ice margin positions (e.g., Svendsen et al, 2004;Fredin et al, 2012). On the assumption that fluctuations in ice margins are driven by variations in climate (Oerlemans et al, 1998;Dyurgerov and Meier, 2000;Putnam et al, 2012), this approach potentially allows moraines to be utilised as proxies for palaeoclimate (e.g., Benn and Ballantyne, 2005;Ballantyne et al, 2007). This link between moraines and palaeoclimate is usually made in one of three ways: (i) moraine positions are used to infer variations in the areal extent of glaciers, and to provide a qualitative understanding of palaeoclimatic variation between periods (e.g., Lasalle and Elson, 1975).…”

“…Glacier-to-glacier variations in total direct snowfall and superimposed ice are largely governed by climate (including topoclimatic factors) (Oerlemans et al, 1998;Dyurgerov and Meier, 2000;Wadham and Nuttall, 2002;Putnam et al, 2012), whilst the redistribution of snow and ice generally occurs through snowblow and avalanching and is controlled by accumulation area topography. Specifically, the volume of redistributed material accumulating on a glacier's surface is determined by the area, slope, and aspect of surrounding topography (Benn and Lehmkuhl, 2000).…”