Decadal Changes in Greenland Ice Sheet Firn Aquifers from Radar Scatterometer

Surface meltwater runoff is believed to be the main cause of alarming mass loss in Greenland Ice Sheet (GrIS); however, recent research has shown that a large amount not directly drained or refrozen but stored form firn aquifers (FAs) interior GrIS. Monitoring changes FAs over GrIS great importance evaluate stability and balance ice sheet. This challenging because are visible on surface direct measurements lacking. A new method proposed map during 2010–2020 period by using C-band Advanced Scatterometer (ASCAT) data based Random Forests classification algorithm with aid from NASA Operation IceBridge (OIB) program. Melt days (MD), melt intensity (MI), winter mean backscatter (WM) parameters derived ASCAT used as input vectors for algorithm. The accuracy model assessed ten-fold cross-validation, overall Kappa coefficient 97.49% 0.72 respectively. results show reached maximum 2015, accumulative area 2010 2020 56,477 km2, which 3.3% area. study provides way investigate long-term dynamics have significance understanding state subsurface subglacial hydrological systems.