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

Open access
Author
Show all
Date
2017-02Type
- Journal Article
Citations
Cited 39 times in
Web of Science
Cited 42 times in
Scopus
ETH Bibliography
yes
Altmetrics
Abstract
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. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000191190Publication status
publishedExternal links
Journal / series
Remote SensingVolume
Pages / Article No.
Publisher
MDPISubject
Sentinel-2; Light-absorbing impurities; Albedo; APEX; glacier; narrow-to-broadband; LandsatOrganisational unit
08726 - Funk, Martin (Tit.-Prof.)
More
Show all metadata
Citations
Cited 39 times in
Web of Science
Cited 42 times in
Scopus
ETH Bibliography
yes
Altmetrics