TY - JOUR
T1 - Effects of vertical inhomogeneity on snow spectral albedo and its implication for optical remote sensing of snow
AU - Zhou, Xiaobing
AU - Li, Shusun
AU - Stamnes, Knut
PY - 2003/12/16
Y1 - 2003/12/16
N2 - The spectral albedo of dry, vertically heterogeneous snow is simulated using a multilayer discrete ordinate method radiative transfer code, with single snow grainscattering parameters calculated either from Mie theory for small grains or from a geometric optics code for large grains. In the near-infrared wavelengths the snowpack is effectively semi-infinite at a depth of around 5 cm; that is, the reflectance is the same as for a deep snowpack. In the visible wavelengths, however, the snow critical depth is more than 50 cm for coarse-grained snow, but the top 5-10 cm layer is the most important one. Two heterogeneous snowpacks with the same average grain size in the topmost layer but with different vertical distributions of grain sizes can have quite different spectral albedos because of greater penetration by visible than by near-infrared radiation. The spectral albedo computed from the multilayer model agrees better with measured albedo when the vertical variability of grain size and the measured composite grain size rather than the measured single grain size are considered.
AB - The spectral albedo of dry, vertically heterogeneous snow is simulated using a multilayer discrete ordinate method radiative transfer code, with single snow grainscattering parameters calculated either from Mie theory for small grains or from a geometric optics code for large grains. In the near-infrared wavelengths the snowpack is effectively semi-infinite at a depth of around 5 cm; that is, the reflectance is the same as for a deep snowpack. In the visible wavelengths, however, the snow critical depth is more than 50 cm for coarse-grained snow, but the top 5-10 cm layer is the most important one. Two heterogeneous snowpacks with the same average grain size in the topmost layer but with different vertical distributions of grain sizes can have quite different spectral albedos because of greater penetration by visible than by near-infrared radiation. The spectral albedo computed from the multilayer model agrees better with measured albedo when the vertical variability of grain size and the measured composite grain size rather than the measured single grain size are considered.
KW - Inhomogeneity
KW - Optical remote sensing
KW - Radiative transfer
KW - Snow and ice
KW - Spectral albedo
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U2 - 10.1029/2003jd003859
DO - 10.1029/2003jd003859
M3 - Article
AN - SCOPUS:1342291004
SN - 0148-0227
VL - 108
SP - ACL 11-1 - ACL 11-15
JO - Journal of Geophysical Research
JF - Journal of Geophysical Research
IS - 23
ER -