A new digital elevation model of Antarctica derived from CryoSat-2 altimetry

• Published in: The cryosphere 2018-05, Vol.12 (4), p.1551-1562
• Main Authors: Slater, Thomas, Shepherd, Andrew, McMillan, Malcolm, Muir, Alan, Gilbert, Lin, Hogg, Anna E, Konrad, Hannes, Parrinello, Tommaso
• Format: Article
• Language: English
• Subjects: Airborne lasers; Airborne sensing; Altimeters; Altimetry; Analysis; Antarctic ice sheet; Arctic research; Cells; Digital Elevation Models; Elevation; Floating ice; Glaciation; Ice; Ice sheets; Ice shelves; Kriging interpolation; Land ice; Laser altimeters; Lasers; Radar; Radar altimeters; Radio altimeters; Resolution; Satellite altimetry; Satellite observation; Satellite radar; Satellites; Sea level; Statistical methods
• ISSN: 1994-0424; 1994-0416; 1994-0424; 1994-0416
• DOI: 10.5194/tc-12-1551-2018

We present a new digital elevation model (DEM) of the Antarctic ice sheet and ice shelves based on 2.5×108 observations recorded by the CryoSat-2 satellite radar altimeter between July 2010 and July 2016. The DEM is formed from spatio-temporal fits to elevation measurements accumulated within 1, 2, and 5 km grid cells, and is posted at the modal resolution of 1 km. Altogether, 94 % of the grounded ice sheet and 98 % of the floating ice shelves are observed, and the remaining grid cells north of 88∘ S are interpolated using ordinary kriging. The median and root mean square difference between the DEM and 2.3×107 airborne laser altimeter measurements acquired during NASA Operation IceBridge campaigns are −0.30 and 13.50 m, respectively. The DEM uncertainty rises in regions of high slope, especially where elevation measurements were acquired in low-resolution mode; taking this into account, we estimate the average accuracy to be 9.5 m – a value that is comparable to or better than that of other models derived from satellite radar and laser altimetry.