Ice-sheet elevation changes caused by variations of the firn compaction rate induced by satellite-observed temperature variations (1982-2003)

Abstract

Changes in the surface elevation of the Greenland and Antarctic ice sheets and ice shelves caused by variations in the rate of firn compaction are calculated with a time-dependent firn densification model driven by two decades (1982-2003) of satellite-observed monthly surface temperatures. The model includes the effects of melting and refreezing, both the direct changes in density and the subsequent effects on the densification rate. As previously shown, the temperature-dependent rate of densification is largest in summer, but changes in winter temperatures also have a significant effect. Over the last decade, climate warming has enhanced the rate of compaction and lowered the average surface elevation of Greenland by 1.8 cma-1 and most of West Antarctica by 1.9 cm a-1. In East Antarctica, a small cooling raised the average surface elevation by 0.14 cm a-l.