Potential of Sentinel-1a for Grounding Line Measurements

Abstract:

The grounding line, the boundary between grounded and floating ice plays a crucial role for mass balance assessment, ice sheet modeling and the analysis of ice shelf melting. Interferometric Synthetic Aperture Radar data are the most accurate means to data to determine the grounding line on a large scale. The analysis of InSAR data from 1996 and 2011 shows a significant retreat of the grounding line in the Amundsen Sea Sector of West Antarctica along a retrograde bed. A new generation of spaceborne SAR sensors (Sentinel-1a, ALOS2) was launched in 2014 and has begun operational data collection since. Sentinel-1a collects data over ice sheets in a novel TOPSAR mode to provide large area coverage at relatively high resolution. Working closely with the ice sheet science community, ESA has implemented a data acquisition plan that ensures at least one ice sheet wide coverage per year and ongoing coverage in key coastal regions. The new mode, however does lead to some challenges in data processing.

With focus on glaciers in West Antarctica (in particular we look at Smith, Pope and Kohler Glaciers), we show the potential of Sentinel-1a for grounding line mapping. Combining data from several currently available missions, we provide a 2015 update for the grounding line in the region.