Hemispherical-directional reflectance factor measurements of snow on the Greenland Ice Sheet during the Radiation, Snow Characteristics and Albedo at Summit (RASCALS) campaign

Abstract

During the summer of 2010 a snow measurement campaign was carried out at Greenland Environmental Observatory, on Greenland Ice Sheet. Broadband snow albedo (bihemispherical reflectance), spectral hemispherical conical reflectance factor, temperature, density and other physical parameters were measured. Especially, the Hemispherical Directional Reflectance Factor (HDRF) of 46 snow samples was measured using the Finnish Geodetic Institute Field Goniospectrometer (FIGIFIGO). Additionally, linear polarization (Stokes parameters I, Q, and U), or Muller matrix elements R11, R12, and R13, were measured from some samples. Albedo was also calculated from the HDRF and these values were compared to those from the albedometer. Values were found to be within 3% of each other, which is within the accuracy limits of the instruments. We also compared our results to previous measurements at the Summit (by Bourgeois et al. during 2005 and Carmagnola et al. during 2011) and found our results to be in agreement with their measurements. Compared to previous studies, our measurements have full solar spectrum spectral coverage and linear polarization.