Seven Years of Tandem-X: Volume Loss of Grosser Aletschgletscher, Switzerland

Grosser Aletschgletscher, the largest glacier in the European Alps, contains 20% of the entire Swiss ice mass. However, mass balance simulations based on current climate models predict 90% mass loss by 2100. The glacier is a super-testsite for the TanDEM-X satellite mission and data series starting from 2011 are available. In this study we analyzed almost 100 digital elevation models computed from bistatic radar in-terferograms and compare the derived height loss with model predictions. Additionally, we used patch-based offset tracking to determine a new velocity map of the complete glacier. The results show that the current height loss of 3.3 meters per year is close to that mass balance simulation which uses the ensemble median of common European climate models which predict, relative to 1999, a warming of 4.3°C by 2100.