Investigating the spatiotemporal features of glacier elevation changes over the southeastern Tibetan Plateau using multisource satellite data
Abstract. Glaciers in the southeastern Tibetan Plateau (SETP) feature the largest maritime glaciers on the Tibetan Plateau (TP) and have experienced accelerated melting in recent decades. Investigating the spatiotemporal features of glacier elevation changes in the SETP remains a challenging task since this region is highly heterogeneous and high spatiotemporal resolution observations for region-wide glacier change measurements are still insufficient. To better understand the spatiotemporal variations in glacier elevation changes in the SETP, multisource satellite observations, including ASTER DEM, ICESat, ICESat-2 and CryoSat-2, are integrated in this study. We derive the spatially resolved glacier change for each year based on the 0.5° × 0.5° geographical tiles, and the obtained glacier elevation change rate of the entire SETP is −0.710 ± 0.046 m/yr during 2000–2022. We divided the study period into a recent decade and the previous decade and found that glacier thinning accelerated at a rate of 31.2 % in the recent decade. We evaluated the correlation between the elevation measurements of different satellites and found that the elevation measurement of ICESat-2 had a slight negative bias relative to the measurements of the other satellites. The ICESat-2 elevation measurements of the strong beam and weak beam were also compared, and no significant difference was observed. We also compared the CryoSat-2 swath measurements with the Level-2 (L2) measurements, and we found that the CyroSat-2 swath data agreed significantly more with the other satellite data than with the L2 measurements. A comprehensive comparison is carried out for the glacier elevation changes obtained in existing studies. Our estimates are highly consistent with those of new published studies and have a finer temporal scale and less estimation uncertainty.
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