Seasonal to interannual variability in Antarctic sea-ice surface melt

Satellite remote sensing time-series images are used to illustrate the spatial and temporal variability in Antarctic-wide seaice surface melting during the austral summer. Combinations of collocated data from the Active Microwave Instrument on board the ERS-1/2 spacecraft, RadarSat Synthetic Aperture Radar (SAR) and SSM/I passive microwave radiometer are used in characterization of the effects of surface melting on measured values of the normalized backscatter cross-section and brightness temperature, respectively. An algorithm is developed from observed signatures to map interannual variations in summer season melt onset and the cumulative number of melt days throughout each austral summer from 19921998. Results indicate that Antarctic sea-ice surface melting is sparse and relatively shortlived, in contrast to the protracted Arctic summer melt season. Regions consistently experiencing melt periods of 15 days or longer duration are focused around the Antarctic Peninsula, primarily in the northwest Weddell and Bellingshausen Seas.