Brief Communication: Contending estimates of 2003–2008 glacier mass balance over the Pamir–Karakoram–Himalaya

We present glacier thickness changes over the entire Pamir–Karakoram–Himalaya arc based on ICESat satellite altimetry data for 2003–2008. We highlight the importance of C-band penetration for studies based on the SRTM elevation model. This penetration seems to be of potentially larger magnitude and variability than previously assumed. The most negative rate of region-wide glacier elevation change (<−1 m yr) is observed for the eastern Nyainqêntanglha Shan. Conversely, glaciers of the western Kunlun Shan are slightly gaining volume, and Pamir and Karakoram seem to be on the western edge of this massgain anomaly rather than its centre. For the Ganges, Indus and Brahmaputra basins, the glacier mass change reaches −24± 2 Gt yr, about 10 % of the current glacier contribution to sea-level rise. For selected catchments, we estimate glacier imbalance contributions to river run-off from a few percent to greater than 10 %.