DEM Generation with ICESat-2 Altimetry Data for the Three Antarctic Ice Shelves: Ross, Filchner–Ronne and Amery

Tong Geng,Jiaxing Li,Feng Xiao,Yue Xuan,Shengkai Zhang,Fei Li,Xiao Li

doi:10.3390/rs13245137

Abstract

The ice shelf is an important component of the Antarctic system, and the interaction between the ice sheet and the ocean often proceeds through mass variations of the ice shelf. The digital elevation model (DEM) of the ice shelf is particularly important for ice shelf elevation change and mass balance estimation. With the development of satellite altimetry technology, it became an important data source for DEM research of Antarctica. The National Aeronautics and Space Administration (NASA) Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) launched in 2018 is a significant improvement in along-track sampling rate and measurement accuracy compared with previous altimetry satellites. This study uses ordinary kriging interpolation to present new DEMs (ICESat-2 DEM hereinafter) for the three ice shelves (Ross, Filchner–Ronne and Amery) in Antarctica with ICESat-2 altimetry data. Two variogram models (linear and spherical) of ordinary kriging interpolation are compared in this paper. The result shows that the spherical model generally shows better performance and lower standard deviation (STD) than the linear models. The precision of the ultimate DEM was evaluated by NASA Operation IceBridge (OIB) data and compared with five previously published Antarctic DEM products (REMA, TanDEM-X PolarDEM, Slater DEM, Helm DEM, and Bamber DEM). The comparison reveals that the mean difference between ICESat-2 DEM of the Ross ice shelf and OIB is −0.016 m with a STD of 0.918 m, and the mean difference between ICESat-2 DEM of the Filchner–Ronne ice shelf and OIB is −0.533 m with a STD of 0.718 m. The three ICESat-2 DEMs show higher spatial resolution and elevation accuracy than five previously published Antarctic DEMs.

Highlights

The ice shelf is the part of land ice that extends over the ocean and floats on it.There are many major or minor ice shelves surrounding the Antarctic coastline, and glaciers on the ice sheet drain into the ocean across the ice shelves
To choose the optimal variogram of ordinary kriging for ice shelf digital elevation model (DEM), experimental areas are selected in each of Ross ice shelf (RIS), Filchner–Ronne ice shelf (FRIS), and AIF, and the linear and spherical models in kriging interpolation are compared and analyzed
The spherical model of the variogram of ordinary kriging is used in DEM processing

Summary

Introduction

The ice shelf is the part of land ice that extends over the ocean and floats on it. There are many major or minor ice shelves surrounding the Antarctic coastline, and glaciers on the ice sheet drain into the ocean across the ice shelves. Iceberg calving from the ice shelf is a major process of Antarctic mass loss, and it has been regarded as a crucial variable in precisely evaluating the mass balance of ice shelves. Ice shelf collapse will lead to accelerated glacier flow and retreating coastlines [6,7,8]

Methods

Findings

Discussion

Conclusion