High-resolution monitoring of internal layers at NGRIP

A key variable in assessing the mass balance of an ice sheet is accumulation rate. Currently, accumulation rate is determined from sparsely distributed ice cores and pits. There are uncertainties in existing accumulation rates derived from these cores and pits. The authors developed an ultra wideband frequency modulated continuous wave (FMCW) radar for mapping internal layers, from known volcanic events, in the ice for estimating accumulation rate from high-resolution radar data. The authors tested the radar system during the 1998 surface experiment at the North Greenland Ice core Project (NGRIP) ice camp. Their results show that internal layers were mapped with high resolution down to 200 m. In this paper, they present the results of the 1998 NGRIP surface experiment.