A decade of West Antarctic subglacial lake interactions from combined ICESat and CryoSat-2 altimetry

Abstract

We use CryoSat-2 interferometric satellite radar altimetry over the Mercer and Whillans ice streams, West Antarctica, to derive surface elevation changes due to subglacial lake activity at monthly resolution for the period 2010 to 2013. We validate CryoSat-2 elevation measurements, trends, and spatial patterns of change using satellite image differencing and in situ vertical movement from Global Positioning System (GPS) data. Two subglacial lake discharge events occur in the same subglacial-hydrological catchment within a 9 month period. Using GPS measurements that are spanning the gap between the Ice, Cloud, and land Elevation Satellite and Cryosat-2 missions, we cross-calibrate the two missions to establish the efficacy of CryoSat-2 altimetry to measure dynamic changes on the ice sheets. Key Points CryoSat-2 altimetry recovers subannual, dynamic ice surface elevation changes GPS data are critical for precise radar and laser altimetry cross-calibration Extended subglacial lake activity time series infers two new discharge events © 2014. American Geophysical Union. All Rights Reserved.