Evaluating the Spatial Variability of Ablation Area Albedo from In Situ and Cross-Platform Satellite Sensors Over the Greenland Ice Sheet

Surface albedo is a critical component of the Greenland ice sheet energy balance. Albedo can be measured in situ or estimated with remote sensing, but comparison between in situ methods and remote observations proves challenging over spatially complex surface types. Here, albedo measurements at high spatial and temporal resolution from the Programme for Monitoring of the Greenland Ice Sheet (PROMICE) automated weather station network are compared with the MODIS MOD10A1 (500m) albedo product. Semivariogram analysis using an independent dataset of high-resolution (3.125m) Planet Labs imagery provided a metric of spatial heterogeneity at each PROMICE location. By relating spatial variability to discrepancies in albedo measurements between different platforms, this study gives insight into the ability of in situ measurements to constrain remotely sensed albedo estimates. These findings will inform current and future parameterization of remotely sensed albedo in regional climate models.