Speaker: Michalea King, Senior Research Scientist,University of Washington, Polar Science Center

Title: Mapping ice motion beyond the Greenland ice sheet’s margins with SAR

Host: Ginny Catania

Abstract: Synthetic Aperture Radar (or SAR) imagery has enabled repeat mapping of the ice sheet surface and flow speeds at nearly regular, sub-monthly resolution since 2015 due to the launch of ESA’s Sentinel-1. These data have been widely utilized by the community to generate ice velocity maps throughout the year, as the C-band SAR imagery is not limited by cloud cover or available sunlight. Our project extends typical velocity mapping approaches used on grounded ice to the areas down-fjord of calving glacier termini around Greenland. Here, fjords are often filled with mélange, or the heterogeneous mixture of calved ice and sea ice that varies in strength, density, and coverage, and can potentially impact ice dynamics by impeding calving from the upstream glacier. We derive velocities of mélange within fjords around Greenland to discern its spatiotemporal variability, rigidity, and evaluate the role mélange can play in ice-ocean interactions and calving dynamics. This talk will also look to the near future and the advances expected with the recent launch of NASA’s NISAR, providing denser SAR coverage in places where high temporal resolution is critical for identifying triggering mechanisms of rapid fjord flushing and glacier calving events.

Learn more about Michalea’s work: michaleaking.github.io