A new digital elevation model (DEM) dataset of the entire Antarctic continent derived from ICESat-2

[摘要] Antarctic digital elevation models (DEMs) are essentialfor fieldwork, ice motion tracking and the numerical modelling of the ice sheet.In the past 30 years, several Antarctic DEMs derived from satellite datahave been published. However, these DEMs either have coarse spatialresolution or aggregate observations spanning several years, whichlimit their further scientific applications. In this study, thenew generation satellite laser altimeter Ice, Cloud, and Land ElevationSatellite-2 (ICESat-2) is used to generate a new Antarctic DEM for both theice sheet and ice shelves. Approximately 4.69  ×  10 9 ICESat-2measurement points from November 2018 to November 2019 are used to estimatesurface elevations at resolutions of 500 m and 1 km based on aspatiotemporal fitting method. Approximately 74 % of Antarctica isobserved and the remaining observation gaps are interpolated using thenormal kriging method. The DEM is formed from the estimated elevations in500 m and 1 km grid cells, and is finally posted at the resolution of 500 m.National Aeronautics and Space Administration (NASA) Operation IceBridge (OIB)airborne data are used to evaluate the generated Antarctic DEM (hereaftercalled the ICESat-2 DEM) in individual Antarctic regions and surface types.Overall, a median bias of − 0.19 m and a root-mean-square deviation of 10.83m result from approximately 5.2  ×  10 6 OIB measurementpoints. The accuracy and uncertainty of the ICESat-2 DEM vary in relation tothe surface slope and roughness, and more reliable estimates are found inthe flat ice sheet interior. The ICESat-2 DEM is comparable to other DEMsderived from altimetry, stereophotogrammetry and interferometry. Similarresults are found when comparing to elevation measurements from kinematic Global Navigation Satellite System(GNSS) (GPS and the Russian GLONASS) transects. The elevations of highaccuracy and ability of annual updates make the ICESat-2 DEM an addition tothe existing Antarctic DEM groups, and it can be further used for otherscientific applications. The generated ICESat-2 DEM (including the map ofuncertainty) can be downloaded from National Tibetan Plateau Data Center,Institute of Tibetan Plateau Research, Chinese Academy of Sciences at https://data.tpdc.ac.cn/en/disallow/9427069c-117e-4ff8-96e0-4b18eb7782cb/ (last access: 27 June 2022)(Shen et al., 2021a, https://doi.org/10.11888/Geogra.tpdc.271448 ).

[学科分类] 眼科学