Greenland Ice Mapping Project: Ice Flow Velocity Variation at sub-monthly to decadal time scales

Area of Science:

• Glaciology
• Remote Sensing
• Climate Science

Background:

• The Greenland Ice Mapping Project (GIMP) has been instrumental in monitoring ice sheet dynamics.
• Understanding ice velocity is crucial for predicting sea-level rise.

Purpose of the Study:

• To present new ice velocity maps for Greenland using Landsat 8 and Copernicus Sentinel 1A/B data.
• To analyze changes in ice flow at specific sites and across broader regions of Greenland since 2000.

Main Methods:

• Utilized Landsat 8 and Copernicus Sentinel 1A/B satellite data to create ice velocity maps.
• Compared new velocity data with historical GIMP data dating back to 2000.
• Analyzed regional speedup trends and winter flow speed changes across Greenland's ice sheet.

Main Results:

• Jakobshavn Isbrae exhibited a substantial slowdown starting in 2017.
• Koge Bugt experienced two major slowdown events coinciding with terminus advances.
• Glaciers in northwest and southwest Greenland collectively continue to accelerate, with regional variations in peak speedup timing.
• Little statistically significant change was found in winter flow speeds along much of the southwest margin.

Conclusions:

• Ice velocity in Greenland shows complex behaviors, including localized slowdowns and regional accelerations.
• Satellite data consistency is generally good, but sensor resolution impacts accuracy in high strain rate areas.
• Users of GIMP data should consider sensor resolution effects for applications like model inversions.