Estimating surface mass balance patterns from unoccupied aerial vehicle measurements in the ablation area of the Morteratsch–Pers glacier complex (Switzerland)

Abstract. The surface mass balance (SMB) of a glacier provides the link between and local climate. For this reason, it is intensively studied monitored. However, major efforts are required to determine point SMB at sufficient number locations capture heterogeneity pattern. Furthermore, because time-consuming costly nature these measurements, detailed measurements carried out on only limited glaciers. In study, we investigate how accurately in ablation zone Vadret da Morteratsch Pers (Engadin, Switzerland) using continuity equation method, based expression conservation for flow with constant density. An elaborate dataset (spanning 2017–2020 period) high-resolution data derived from unoccupied aerial vehicle (UAV) (surface elevation changes velocities) combined reconstructed ice thickness fields (based radar measurements). To performance compare modelled measured values position stakes. Our results indicate that annual UAV surveys, possible obtain estimates mean absolute error smaller than 0.5 m equivalent per year. Yet, our study demonstrates accuracies, necessary consider over spatial scales several times thickness, accomplished by applying an exponential decay filter. highlights crucial importance which must be sufficiently well known order apply method. latter currently seems complicate application method derive patterns regional global scales.