Mass loss from the Greenland Ice Sheet (GrIS) has accelerated in recent years, where increases in surface melt leading to increased ice sheet runoff are only partly responsible. Some more dramatic changes were observed in the late 1990s and continued through the first years of the past decade. The flow velocities of many tidewater outlet glaciers around Greenland increased to as much as double their former speed accompanied by rapid retreat of their calving fronts and dynamic thinning spreading inland. Since the dynamic component contributed about 50% to the overall mass loss, further understanding of the nature, distribution, and controls on dynamic change is essential for predicting Greenland's future sea-level contribution.

Nevertheless, the primary control on the dynamic changes has remained unclear, as observations are not widespread and frequent enough to quantify and understand the contemporary variations with sufficient temporal and spatial coverage. Furthermore, almost all available measurements are only 10 to 15 years in length, leaving an urgent need to place the contemporary findings in a broader temporal context.

This lack of knowledge will specifically be addressed by the EXCITING project. It aims at producing a high temporal resolution sequence of Greenland outlet glacier dynamics (frontal position and surface speed) for the longest time feasible from satellite imagery in order to identify the distribution and controls of dynamic mass loss in Greenland. The outcome of this project will be up to 30-year-long time sequences of margin locations and velocity changes for a high number of Greenland outlet glaciers. Imagery of various satellite systems (SAR and optical) is available from ESA archives back to the 1980s. It will be utilized together with current imagery to greatly increase our knowledge of the inter- and intra-annual dynamics of Greenland outlet glaciers, identify their controls and help answering the question of whether recent changes in Greenland represent a profound change in the ice sheet, or simply the expected inter-annual variability.