Naegeli, Kathrin Damm, Alexander Huss, Matthias Wulf, Hendrik Schaepman, Michael Hoelzle, Martin 2017-01-27 Surface albedo partitions the amount of energy received by glacier surfaces from shortwave fluxes and modulates the energy available for melt processes. The ice- albedo feedback, influenced by the contamination of bare-ice surfaces with light- absorbing impurities, plays a major role in the melting of mountain glaciers in a warming climate. However, little is known about the spatial and temporal distribution and variability of bare-ice glacier surface albedo under changing conditions. In this study, we focus on two mountain glaciers located in the western Swiss Alps and perform a cross-comparison of different albedo products. We take advantage of high spectral and spatial resolution (284 bands, 2 m) imaging spectrometer data from the Airborne Prism Experiment (APEX) and investigate the applicability and potential of Sentinel-2 and Landsat 8 data to derive broadband albedo products. The performance of shortwave broadband albedo retrievals is tested and we assess the reliability of published narrow-to-broadband conversion algorithms. The resulting albedo products from the three sensors and different algorithms are further cross-compared. Moreover, the impact of the anisotropy correction is analysed depending on different surface types. While degradation of the spectral resolution impacted glacier-wide mean albedo by about 5%, reducing the spatial resolution resulted in changes of less than 1%. However, in any case, coarser spatial resolution was no longer able to represent small-scale variability of albedo on glacier surfaces. We discuss the implications when using Sentinel-2 and Landsat 8 to map dynamic glaciological processes and to monitor glacier surface albedo on larger spatial and more frequent temporal scales. application/pdf https://folia.unifr.ch/global/documents/305210 https://folia.unifr.ch/documents/305210/files/nae_cca.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.3390/rs9020110 info:eu-repo/semantics/openAccess License undefined Remote Sensing. - 2017, vol. 9, no. 2, p. 110 glacier Albedo Light-absorbing impurities APEX Sentinel-2 Landsat narrow-to-broadband info:eu-repo/classification/udc/556 Cross-comparison of albedo products for glacier surfaces derived from airborne and satellite (sentinel-2 and landsat 8) optical data http://purl.org/coar/resource_type/c_6501