Estimates of Snow Accumulation Rates Over the Greenland Ice Sheet Using Airborne Radar
Hans Peter Marshall
Accurate estimates of ice sheet properties are important in climate studies. Of these properties, accumulation rates for the Greenland Ice Sheet are essential in calculating mass balance models for use in many climate models. Due to the small number of point measurements of snow and ice properties, accumulation rates over the entire ice sheet are poorly understood. It is hoped that through the use of airborne radar imaging of the ice sheet provided by NASA's IceBridge project, ice core information from the GISP2 ice core, and other ground truth measurements, that more accurate estimates for accumulation rates can be obtained. Reflections of layers present over the entire ice sheet were picked from all radar images and then were used to generate a stratigraphic profile in time for the ice sheet. The profile was then converted to depth through the estimates of density and electrical properties of snow and ice. Individual layers are then dated through the use of average accumulation rates which then allowed us to estimate accumulation rates over the entire sheet coupled with the spatial variation of layer thicknesses and depths.