Change monitoring of Antarctic sea ice using NSCAT dual-polarized backscatter measurements

Polar sea ice characteristics and the timing of seasonal transitions are important parameters in the study of polar processes and climate changes. NSCAT Ku-band active microwave observations of the Antarctic sea ice cover are described in this article with emphasis on the monitoring of ice covers through the change of Ku-band backscatter signatures. A simple backscatter and polarization ratio threshold algorithm was used to discriminate sea ice and open water with NSCAT dual-polarized backscatter data. The estimated backscatter of classified sea ice pixels is illustrated. The new first year (FY) and pancake ice have a backscatter level similar to those of corresponding ice types in the Arctic, although the ice growth mechanisms are quite different. The significant changes of ice backscatter in the Weddell Sea correlates well the timing of fall freeze-up. This should provide a useful large-scale estimate of the dates of freeze-up. A more extensive validation of the potential of this dataset is definitely suggested.