Polar and cold regions research at the German Aerospace Center (DLR)

Kurzfassung

The polar and cold regions play a significant role in the context of climate change, sea level rise, and water availability. Earth observation (EO) based applications are essential to monitor and understand climate change impacts on the cryosphere. At the German Aerospace Center (DLR), strong efforts are made to gain a better understanding of cold and polar regions by exploiting high-volumes of multi-sensor satellite data with high performance computing and artificial intelligence. This offers the opportunity to compute long time series of land surface dynamics to track and quantify ongoing changes. We will present these efforts through four different EO applications developed at DLR: (1) The Global SnowPack monitors daily global snow cover based on MODIS and VIIRS since the year 2000. The 23-year time series revealed a global decrease in snow cover duration by 4.4 days/decade. (2) Snow line elevation monitoring in the Alps with Landsat satellite data revealed snow lines moving to higher elevations. Since 1985, the snow line of the Central and Western Alps moved upwards with highest rates of 50-80 m/decade. (3) In Antarctica, we implemented an automatic supraglacial lake mapping by fusing Sentinel-1 and -2 data over six Antarctic ice shelves. This allows bi-weekly mapping of maximum lake extents and revealed highest meltwater coverage reached ~805 km2 over George VI Ice Shelf in late January 2020. (4) Additionally, we monitor Antarctic ice shelf fronts based on Sentinel-1 data. The automatically extracted fronts (>19.000) are available at the EOC GeoService and are updated on a monthly basis to provide a continuous and ongoing time series of Antarctic ice shelf front change. The advance rate of Pine Island Glacier was identified as the highest advance rate with 4.72 km/yr in 2021. Overall, our developments demonstrate that automated EO applications generate valuable time series of cryospheric change to analyze trends and sudden change. This allows us to find answers how climate change is affecting the polar and cold regions and which consequences these processes might entail nature and society.