Modeling interpretation of scattering from snow-covered sea ice

Radar scattering measurements of saline ice at 5.3 and 13.4 GHz were collected during the 1990 and 1992 winter seasons at the US Army Cold Regions Research and Engineering Laboratory (CRREL). Both like and cross polarizations were obtained from saline ice with and with out snow cover. The results of these measurements were examined with a radiative transfer model applied to inhomogeneous layers with densely populated discrete scatterers. It is found that bare saline ice has a low albedo and hence its like polarized backscattering is dominated by the irregular air-ice interface over 10 to 50 degrees. The effect of volume scattering is observable between 50 to 60 degrees. For cross polarized scattering, volume scattering effect is also small compared with surface scattering. When there is snow cover, there is a general increase in scattering along nonspecular directions. This is attributed to the brine wicking effect which causes a higher concentration of brine along the interface region and a possible roughening of the snow-ice interface