The effects of surface roughness on the calculated, spectral, conical–conical reflectance factor as an alternative to the bidirectional reflectance distribution function of bare sea ice

Abstract. The conical–conical reflectance factor (CCRF) has been calculated as an alternative to the bidirectional distribution function (BRDF) for three types of bare sea ice with varying surface roughness (?= 0.1–10) and thicknesses (50–2000 cm) over incident solar irradiance wavelength range 300–1400 nm. comprehensive study CCRF presented here is paramount interpreting measurements from satellite imagery inter-calibrating space-borne sensors that derive albedo multiple multi-angular measurements. calculations performed by a radiative-transfer code (PlanarRad) show sensitive realistic values roughness. results cannot be considered independently thickness, zenith angle wavelength. A typical quasi-isotropic hemisphere, associated strong forward-scattering peak photons. Surface crucial location, size intensity peak. As increases, spreading observed. hemisphere was split in 216 quadrangular regions or quads. remains specular smaller roughnesses (?=0.001 ?=0.01), whereas larger features (above ?=0.05), spreads out quads lower than features, highest value displaced further on principal plane. Different have similar pattern wavelength: increases 30 % first-year multi-year at 400 nm up 631 1100 nm, 32 melting maximum 98 900 11 86 800 this form first set complete approximation BRDF wide configurations.