Airborne laser altimetry mapping of the Greenland ice sheet: application to mass balance assessment

摘要: Abstract In 1998 and 1999, the Arctic Ice Mapping (AIM) program completed resurveys of flight lines occupied 5 years earlier revealing elevation changes Greenland ice sheet identifying areas significant thinning, thickening balance. planning these surveys, consideration had to be given spatial constraints associated with aircraft operation, nature behavior, limited resources, as well temporal issues, such seasonal interannual variability in context measurement accuracy. The surveys covered entire an average distance 21.4 km between each location on nearest line. For most sheet, show relatively little variability, their magnitudes are significantly smaller than observed change signal. As a result, we conclude that density sampling accuracy measurements sufficient draw meaningful conclusions state balance over 5-year survey period. Outlet glaciers, however, far more major ones is likely require individual order determine its