Elevation changes of High Mountain Asia and the Gulf of Alaska, observed by CryoSat-2 swath altimetry between 2010 and 2019

We report the first application of a novel approach to retrieve spatially-resolved elevation change from radar altimetry over entire mountain glaciers areas. We apply interferometric swath altimetry to CryoSat-2 data acquired between July 2010 and July 2019 over High Mountain Asia (HMA) and in the Gulf of Alaska (GoA). We bin swath elevation data into 100 x 100 km bins, remove the topography with a reference DEM and generate linear rates of elevation changes for each bin individually using a weighted regression model. We exclude solutions that that did not fulfil a set of quality criteria based on elevation change uncertainties, temporal completeness, interannual changes and stability of regression results. To extrapolate missing data, hypsometric averaging is applied. We find that during the study period, HMA and GoA have lost an average of –28.0 ± 3.0 Gt yr–1 (–0.29 ± 0.03 m w.e. yr–1) and –76.3 ± 5.7 Gt yr–1 (–0.89 ± 0.07 m w.e. yr–1) respectively. Glacier thinning is ubiquitous except for the Karakoram-Kunlun region experiencing stable or slightly positive mass balance