Remote sensing reveals shrinking Greenland ice sheet



Since sea level rise over the past century can be only partially explained by ocean warming and melting of non-polar ice, we can safely assume that the volume of the Greenland and Antarctic ice sheets probably is decreasing. However, many decades of glaciological observations have yet to yield even a good estimate of the collective mass balance of these two ice sheets. Until recently this uncertainty applied equally to both ice sheets. Then NASA's Program for Arctic Regional Climate Assessment (PARCA) researched the mass balance of the Greenland ice sheet by measuring changes in icesheet volume through different approaches, by analyzing satellite and aircraft data to investigate various characteristics of the ice sheet, and by conducting in situ measurements aimed at understanding observed changes.