Glacier specific ablation rate derived by remote sensing measurements

The specific ablation rate in a transect of Storstrømmen, a large outlet glacier from the Northeast Greenland ice sheet, is derived by combining airborne laser altimetry measurements with emergence/submergence velocities derived from satellite synthetic aperture radar interferometry (InSAR) and airborne ice-sounding radar measurement of ice thickness. The results are compared with in situ point observations of ablation measured at poles drilled into the glacier. Considering the different measurement periods for the different data sets, the agreement between derived and observed ablation rates is satisfactory. The new method of deriving specific mass balance, particularly ablation rate, by remote sensing measurements alone has the potential to substantially increase the density of observational based ablation rates on ice sheet and ice cap margins.