Anisotropy Parameterization Development and Evaluation for Glacier Surface Albedo Retrieval from Satellite Observations

Glacier albedo determines the net shortwave radiation absorbed at glacier surface and plays a crucial role in energy mass balance. Remote sensing techniques are efficient means to retrieve over large inaccessible areas study its variability. However, corrections of anisotropic reflectance have been established for specific bands only, such as Landsat 5 Thematic Mapper (L5/TM) band 2 4, which is major limitation current retrievals broadband albedo. In this study, we calibrated evaluated four anisotropy correction models snow ice, applicable visible, near-infrared shortwave-infrared wavelengths using airborne datasets Bidirectional Reflectance Distribution Function (BRDF). We then tested ability best-performing model, referred from here on ‘updated model’, L5/TM, 8 Operational Land Imager (L8/OLI) Moderate Resolution Imaging Spectroradiometer (MODIS) imagery, these results with field measurements collected eight glaciers around world. Our show that updated model: (1) can accurately estimate factors ice surfaces; (2) generally performs better than prior approaches L8/OLI retrieval but not appropriate L5/TM; (3) retrieves MODIS standard product (MCD43A3) both absolute values temporal evolution, i.e., exhibiting fewer gaps agreement observations. As model enables maximum 10 multispectral implemented Google Earth Engine (GEE), it promising observing analyzing spatial scales.