A 19-Year Radar Altimeter Elevation Change Time-Series of the East and West Antarctic Ice Sheets
Sundal, Aud1; Shepherd, Andrew1; Wingham, Duncan2; Muir, Alan2; McMillan, Malcolm1; Galin, Natalia2
1University of Leeds, UNITED KINGDOM; 2University College London, UNITED KINGDOM

We present 19 years of continuous radar altimeter observations of the East and West Antarctic ice sheets acquired by the ERS-1, ERS-2, and ENVISAT satellites between May 1992 and September 2010. Time-series of surface elevation change were developed at 39,375 crossing points of the satellite orbit ground tracks using the method of dual cycle crossovers (Zwally et al., 1989; Wingham et al., 1998). In total, 46.5 million individual measurements were included in the analysis, encompassing 74 and 76 % of the East and West Antarctic ice sheet, respectively. The satellites were cross-calibrated by calculating differences between elevation changes occurring during periods of mission overlap. We use the merged time-series to explore spatial and temporal patterns of elevation change and to characterise and quantify the signals of Antarctic ice sheet imbalance.

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