SIR-C polarimetric radar results from the Weddell Sea, Antarctica

Polarimetric radar data acquired by SIR-C in the Eastern Weddell Sea have been analyzed to investigate techniques for discriminating thin, recently formed sea-ice from thicker first year ice and open water. Several different parameters from both the L-band and the C-band have been studied to understand the scattering processes for different forms of ice. Results indicate that it is possible to differentiate between all the primary ice types appearing in the area (except between brash ice and deformed first year ice) by comparing a combination of two or three of the studied parameters. Several different combinations can be used, but the best results are found when the L-band VV-polarized backscatter and HH- and VV-pol correlation coefficient, and the co-pol ratio HH/VV in C-band are combined. Thanks to the high quality of the SIR-C data, small differences are observed which make it possible to discriminate at least two distinctive thin ice sub-groups. This increases the possibility to use these data to study how new ice evolves under these unique Southern Ocean conditions.