Circular-polarization radar properties of high-altitude ice: Western Kunlun Shan and central Andes

Full polarization synthetic aperture radar images of high-altitude glaciers and ice fields in the Western Kunlun Shan of Tibet and the central Andes n ear Santiago, Chile, made with the shuttle imaging radar, display regions w ith circular-polarization ratios, mu(c), in excess of unity. The mountainou s topography at both locales allows reconstruction of the angular scatterin g behavior. The behavior is very similar to that displayed by Greenland's p ercolation zone. Glaciologic evidence from the Tibetan site confirms ice pi pes and lenses embedded in the firn, which have been identified as the scat terers producing mu(c)>1 in Greenland. This demonstrates that the cold snow percolation facies radar signature exists outside of Greenland. The Greenl and radar behavior had been suggested as an analogue for that of the icy Ga lilean satellites. We, like previous workers, find that the near-nadir back scatter is too specular to be considered analogous to that of the Jovian mo ons. We also present a crevasse region in Tibet that exhibits mu(c)>1 and a possible detection of the ice substrate of a rock-covered glacier in the A ndes.