Surface velocities for selected key regions in Greenland and Antarctica

Surface velocities for the onset of the North East Greenland Ice Stream (NEGIS) are based on SAR interferometry using ascending and descending satellite tracks and the assumption of surface parallel ice flow. Data for the high resolution field (30 m res) in the vicinity of the EGRIP drill site were acquired by TerraSAR-X between 2016 and 2018. TerraSAR-X raw data were made available through DLR proposal HYD2059. Another velocity field at the onset of NEGIS is a mosaic of Sentinel-1 estimates acquired in early 2019, following a similar interferometric processing scheme as for the TerraSAR-X velocity field. The third velocity mosaic covers large parts of NE Greenland and was derived by intensity offset tracking on Sentinel-1 winter acquisitions between 2016 and 2018. Surface velocities in the region of the Filchner-Ronne Ice Shelf (Antarctica) were derived from Sentinel-1 and TerraSAR-X intensity offset tracking and filled with Landsat 8 velocity estimates downloaded from the Global Land Ice Velocity Extraction from the Landsat 8 (GoLIVE) database (Scambos et al., 2016). The higher resolved velocity field of Support Force Glacier (50 m res) is only based on TerraSAR-X intensity offset tracking and GoLIVE velocity estimates. TerraSAR-X raw data were made available through DLR proposal HYD2059.