LONG-TERM MONITORING OF WATER DYNAMICS IN THE SAHEL REGION USING THE MULTI-SAR-SYSTEM

This study analyses the basal sliding and the hydrological drainage of Baltoro Glacier, Pakistan. The surface velocity was characterized by a spring speed-up, summer peak, and fall speed-up. Snowmelt has the largest impact to the spring speed-up, summer velocity peak, and to the transition from inefficient to efficient drainage. Drainage from supraglacial lakes contributed to the fall speed-up. Increased summer temperatures will intensify the magnitude of melt water and thus surface velocities.

Changes in the state of the snowpack in the context of observed global warming must be considered to improve our understanding of the processes within the cryosphere. This study aims to characterize an arctic snowpack using the TerraSAR-X satellite. Using a high-spatial-resolution vegetation classification, we were able to quantify the variability in snow depth, as well as the topographic soil wetness index, which provided a better understanding of the electromagnetic wave–ground interaction.

We present a new digital elevation model (DEM) of Antarctica derived from the TanDEM-X DEM, with new interferometric radar acquisitions incorporated and edited elevations, especially at the coast. A strength of this DEM is its homogeneity and completeness. Extensive validation work shows a vertical accuracy of just -0.3 m ± 2.5 m standard deviation on blue ice surfaces compared to ICESat laser altimeter heights. The new TanDEM-X PolarDEM 90 m of Antarctica is freely available.

Inuit have reported greater variability in seasonal sea ice conditions. For Deception Bay (Nunavik), an area prized for seal and caribou hunting, an increase in snow precipitation and a shorter snow cover period is expected in the near future. In this context, and considering ice-breaking transport in the fjord by mining companies, we combined satellite images and time-lapse photography to monitor sea ice in the area between 2015 and 2018.