Mapping Surface Albedo from the Complete Landsat Archive since the 1980S and Its Cryospheric Application

摘要

Surface albedo is one of the essential climate variables. There is an increasing need for albedo data to be available for use in applications that require a medium to fine spatial resolution. In our earlier study, the direct estimation approach, previously used with coarser resolution data, was refined and applied to the Landsat data archive, including MSS, TM, ETM+, and OLI. Extensive validations made against ground measurements showed that the albedo estimation algorithm could achieve low root-mean-squared-errors (RMSEs) not more than 0.031 over both snow-free and snow-covered surfaces. In this study, the algorithm was used with Landsat data to map the surface albedo changes in the ablation zone over west Greenland since 1980s, where massive melting events occurred during the past few decades. As a case study, an analysis of surface albedo change over Greenland combining four satellite albedo datasets, namely MODIS, GLASS, CLARA, and Landsat was conducted to better understand the magnitude and timing of albedo changes in the ablation zone.