Multi-annual changes in microwave backscatter over the Greenland ice sheet

Changes in the location of key ice facies/zones on the Greenland ice sheet are considered key indicators of global climate change. Microwave scatterometers are effective tools for monitoring these changes. Measurements for three Ku-band scatterometers, SASS (1978), NSCAT (1996), and SeaWinds (1999-present), span a 23-year period. While the ERS scatterometer (C-band) offers a continuous 9-year dataset (1992-2000). Using the SIR algorithm to produce /spl sigma//sup 0/ images, the measurements made by these sensors over Greenland are compared. We find an increase in /spl sigma//sup 0/ along the southern border between the dry snow zone and percolation zone, and a decrease for C-band measurements along the northern portions of this boundary.