Melt detection in Antarctic ice-sheets using spaceborne scatterometers and radiometers

Backscatter measurements from the Sea Winds on QuikSCAT scatterometer are used to determine periods of surface freeze and melt on Antarctic ice-shelves. A maximum likelihood method is used to infer the daily ice-surface conditions for various study points located on the Ronne, Ross, Larsen, Fimbul, Amery, and Shackleton ice-shelves. Criteria for determining the dates of melt-onset and freeze-up for each Austral summer are presented. Validation of the ice-state and melt-onset date estimates is performed by analyzing the corresponding brightness temperature (T_b) measurements from special sensor microwave/imager (SSM/I) radiometers. QuikSCAT σ° measurements from 1999 through 2003 are analyzed and found to be very useful for determining periods of melt in Antarctic ice-sheets and provide high temporal and spatial resolution ice-state estimates.