Estimating spatiotemporal variations of albedo in the Olivares glaciers, central Chile

Abstract

This study derived albedo measurements from the Olivares Alfa, Beta and Gama glaciers, placed on the central Chilean Andes, by processing Landsat-8 satellite images acquired in January 1990, 1996 and 2017. The aim was to estimate spatiotemporal variations of such a variable. Between 1990 and 2017, the average albedo of the Olivares Alfa glacier decreased by 0.17 (0.43-0.26), which translated into an annual rate of decrease of 1.78%. On the same period, the average albedo of Olivares Beta glacier decreased by 0.09 (0.48-0.39), which translated into an annual rate of decrease of 1.33%, while the average albedo of the Olivares Gama glacier decreased by 0.12 (0.45-0.33), translating into an annual rate of decrease of 1.1%. The mapping of the albedo differential of each glacier, resulting from subtracting the 1990 albedo from the 2017 albedo, enabled to appreciate the spatial variations of the variable, which evidenced its largest decreases on both, accumulation and ablation glacier zones. The remote sensing-derived albedo could be included in the mass balance of these and other glaciers of the country. This would enable to assess the impact of the decreasing of this variable on the ice loss and its relationship with the climatic variability induced by the global warming and climate change.