Rapid basal channel growth beneath Greenland's longest floating ice shelf

This dataset contains ice surface elevation reconstructions, floating ice bottom elevation reconstructions, and Lagrangian surface elevation change estimates for the Northeast Greenland Ice Sheet outlet region, focused on Nioghalvfjerdsfjorden Glacier (N79); as well as elevation time series for select locations.

The surface elevation reconstructions (beginning with "dem_mosaic_") consist of mosaics of WorldView stereoimage DEMs from the ArcticDEM project that have been individually corrected using laser altimetry (ATM, ICESat, and ICESat-2). These elevations are referenced to the WGS84 datum, and include reconstruction for 2012, 2014-2017, and 2020.

The ice bottom reconstructions (beginning with "dem_ice_bottom_") apply a hydrostatic assumption to the surface elevation reconstruction to infer the bed elevation. These elevations are referenced to the Eigen-6c4 geoid, and include all the years above, as well as 1978, based on DEMs from aerial photographs.

The Lagrangian elevation change reconstruction (beginning with "lagrangian_elevation_change_") is derived from comparing elevation values in successive time periods, using velocity values to infer displacement over the interim and match pixels that represent the same ice parcel. Reported values correspond to the end point of this migration.

The time series file ("TimeSeriesTile26_partitioned_selected.txt") contains SERAC elevation time series for 6 locations near the N79 grounding line.