Ice displacement anomalies documented in "Episodic Subglacial Drainage Outbursts Below the Northeast Greenland Ice Stream"

This repository contains data documenting ice displacements resulting from a cascade of subglacial drainage outbursts below the Northeast Greenland Ice Stream (NEGIS). The data is presented and analyzed in the manuscript: "Andersen et al. (2023) Episodic Subglacial Drainage Outbursts Below the Northeast Greenland Ice Stream" (submitted to Geophysical Research Letters).

The repository contains the following:

- UpliftEvents_vlosDiff_T112D.zip a collection of GeoTIFF files, each containing measurements of ice displacement anomalies for a local inferred uplift event. The displacements are measured with the DInSAR (Differential Synthetic Aperture Radar Interferometry) method using Sentinel-1 satellite data. The displacement anomalies are projected to the slanted satellite line-of-sight vector, and are given as a velocity anomaly (in units of meters/year), as this is the output of the applied DInSAR algorithm. Converting the observed line-of-sight anomaly, v_LoS, to a vertical displacement, d_vert, is then done through:

               d_vert = v_LoS / cos(a) * T      (1)

where a is the local incidence angle of the satellite line-of-sight and T is the temporal baseline (6 days for all measurements). All measurements are from the descending Sentinel-1 track 112. Filenames follow the format "vlosDiff__YYYYMMDD_YYYYMMDD_X.tif", where the two dates reflect the first and second acquisition dates used to make the measurement and X refers to the event number/index (some retrievals contain multiple individual uplift events). Measurements are provided on a 50x50 m grid (EPSG:3413).

- T112D_incidence_angle.tif GeoTIFF file containing the incidence angle for Sentinel-1 track 112 over the entire study area (can be used to convert line-of-sight anomaly measurements to vertical displacements, as per eq. (1) above). Provided in 50x50 m grid (EPSG:3413) in units of degrees.

- InferredDrainagePathways.zip Subglacial drainage propagation pathways inferred from all DInSAR measurements carried out in the study (cf. Figure 1 of the manuscript). 

Corresponding author: Jonas Kvist Andersen (jkvand@space.dtu.dk)