Towards ice-thickness inversion: an evaluation of global digital elevation models (DEMs) in the glacierized Tibetan Plateau

Abstract. Accurate estimates of regional ice thickness, which are generally produced by ice-thickness inversion models, crucial for assessments available freshwater resources and sea level rise. A digital elevation model (DEM) derived from surface topography glaciers is a primary data source such models. However, the scarce in situ measurements glacier limit evaluation DEM uncertainty. Hence influence uncertainty on modeling remains unclear over glacierized area Tibetan Plateau (TP). Here, we examine performance six widely used mainly global-scale DEMs: AW3D30 (ALOS – Advanced Land Observing Satellite World 3D 30 m; m), SRTM-GL1 (Shuttle Radar Topography Mission Global 1 arc second; NASADEM (NASA Digital Elevation Model; TanDEM-X (TerraSAR-X add-on Measurement, synthetic-aperture radar; 90 SRTM v4.1 Mission; MERIT (Multi-Error-Removed Improved-Terrain; m) TP comparison with ICESat-2 (Ice, Cloud land Satellite) laser altimetry while considering effects dynamics, terrain factors, misregistration. The results reveal to be best performer vertical accuracy, small mean error (ME) 0.9 m root squared (RMSE) 12.6 m, followed (2.6 ME 11.3 RMSE). also performs well (0.1 15.1 RMSE) but suffers serious errors outliers steep slopes. SRTM-based DEMs (SRTM-GL1, v4.1, MERIT) (13.5–17.0 had an inferior NASADEM. Errors increase south-facing north-facing aspect become larger increasing slope. Misregistration relative footprint most areas (less than one grid spacing). In next step, four models GlabTop2 (Glacier bed Topography), Open Glacier Model (OGGM), Huss–Farinotti (HF), Ice Thickness Inversion Based Velocity (ITIBOV) intercompared. show that sensitive accuracy both slope, OGGM HF less quality resolution, ITIBOV slope accuracy. choice whole TP.