Seasonal and interannual variations in Antarctic backscatter signature from 2000 to 2006 as observed by QuikSCAT

Time-series analysis of Antarctic QuikSCAT data reveals several trends. An annual seasonal cycle in which backscatter power increases during the Austral winter and decreases during the Austral summer, is observed over most of the continent, with varying magnitude. Several areas also show a large ( ∼ 10dB) decrease in average backscatter during the Austral summer, suggesting melt events. As expected, seasonal variations are strongly dependent on latitude; the southernmost observable portion of the continent is much less seasonably variable than the coasts. Interanual trends show strong long-term trends superimposed on seasonal cycles in much of the continent. Along the coast of most of the continent, backscatter has consistently increased, on the order of 0.5 dB/year, during the seven-year study period. Other regions, mostly in the West-Antarctic interior show the opposite trend, with average backscatter decreasing on the order of 0.5 dB/year.