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Abstract

Assessments of glacier height and mass changes are more and more based on differencing digital elevation models (DEMs) from different sources. Those data sets provide glacier specific assessments, but spaceborne missions can also deliver regional-scale analyses. However, each method and mission shows specific advantages and limitations. In this context, the IACS Working Group on Regional Assessments of Glacier Mass Change (RAGMAC) launched an intercomparison exercise. It aims to provide an overview of good practises as well as spread of different processing approaches for assessing glacier volume changes from spaceborne DEM differencing. The activity was split into two experiments with mandatory and optional tasks. In total, 12 groups participated in the experiment and contributed glacier elevation change results to the first or second or both experiments. Experiment 1 targeted a comparison of spaceborne elevation changes to high-quality, high-resolution airborne data as well as to in-situ surface glacier mass balance data. The outcome of this first experiment provides insights how the participants account for the mismatch between DEM acquisition dates and and reference period. Experiment 2 was setup for regions where no direct validation data was available. The challenge posed here was on the intercomparison and influence of different processing steps. Therefore, participants were asked to provide elevation change estimates of specific experimental setups. The presentation will provide an overview of the exercise and analysis of the submitted contributions.