Laurie Padman
Earth & Space Research, 1910 Fairview Ave. East, Suite 210, Seattle, WA 98102, USA.

Helen A. Fricker
2Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093-0225, USA.




The Ice, Cloud and land Elevation Satellite (ICESat) provides the first opportunity for measurement of surface elevation h_i over the portions of the Antarctic ice shelves that are south of the European Remote Sensing satellite maximum latitude (81.5^oS). The dominant source of short-period variability in h_i is ocean tides. We use crossover elevation difference (Δh_i) data from the Ross Ice Shelf (RIS) to demonstrate ICESat's ability to detect the tidal signal, and to compare the accuracy of several tide models. The root-mean-square (rms) value of all RIS measurements of Δh_i is ≈0.74 m; after removing the tide using the most accurate model, the rms of the residual signal in regions of optimal model performance is ≈0.16±0.03 m. This value corresponds to an uncertainty in h_i of 0.11 ± 0.02 m. We postulate that the primary sources of the residual signal are tide model errors and the inverse barometer effect.