Cross-Comparison of Albedo Products for Glacier Surfaces Derived from Airborne and Satellite (Sentinel-2 and Landsat 8) Optical Data

Cross-Comparison of Albedo Products for Glacier Surfaces Derived from Airborne and Satellite (Sentinel-2 and Landsat 8) Optical Data

Blog Article

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 joico lumishine 10n 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 deity deftrap 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.