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

• Main Authors: Jonas Kvist Andersen, Nicholas Rathmann, Christine Hvidberg, Aslak Grinsted, Anders Kusk, John Peter Merryman Boncori, Jeremie P Mouginot
• Format: Dataset
• Language: unknown
• Published: 2023
• Subjects: Glaciology; subglacial drainage; Greenland; DInSAR measurements; sentinel-1
• Online Access: https://doi.org/10.11583/dtu.22060061.v1; https://figshare.com/articles/dataset/Ice_displacement_anomalies_documented_in_Episodic_Subglacial_Drainage_Outbursts_Below_the_Northeast_Greenland_Ice_Stream_/22060061

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). ...