Theoretical study of solar light reflectance from vertical snow surfaces

摘要

The influence of horizontal and vertical inhomogeneity of snow surfaces onsolar light reflectance is studied using the radiative transfer theory (RTT).We compared 1-D RTT and 2-D RTT and found that large errors are produced ifthe 1-D RTT is used for the calculation of the snow reflection function (and,therefore, also in the retrievals of the snow grain radii) in 2-D measurementgeometries. Such 2-D geometries are common in the procedures for thedetermination of the effective snow grain radii using near-infraredphotography and spectroscopy of vertical snow walls. In particular, we haveconsidered three cases for the numerical calculations: (1) the case with noblack film; (2) the case with a black film at the pit's bottom; (3) the casewith a black film at the pit's bottom and also at one of the vertical snowwalls.