Impact of resolution and radar penetration on glacier elevation changes computed from DEM differencing

Digital elevation models (DEMs) are now frequently used to calculate elevation changes and regional mass balances of glaciers, for example in the Alps (Berthier and others, 2004; Paul and Haeberli, 2008; Huss and others, 2010), Alaska and Canada (Larsen and others, 2007; Schiefer and others, 2007; Berthier and others, 2010), Patagonia (Rignot and others, 2003) or High Mountain Asia (Surazakov and Aizen, 2006; Berthier and others, 2007; Bolch and others, 2011). Geodetic mass balance measurements from space-borne imagery are indeed useful to assess glacier changes in remote or wide areas and thus, better constrain glacier losses and contribution to sea level rise (Cogley, 2009). Previous studies have demonstrated that a thorough processing strategy is mandatory (i.e. a proper horizontal and vertical adjustments of the two DEMs to be substracted) to compute unbiased elevation changes from multi-temporal space-borne DEMs (e.g. Nuth and Kääb, 2011).