Effects of snow physical parameters on spectral albedo and bidirectional reflectance of snow surface

Teruo Aoki, Tadao Aoki, Masashi Fukabori, Akihiro Hachikubo, Yoshihiro Tachibana, Fumihiko Nishio

Research output: Contribution to journalArticle

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Abstract

Observations of spectral albedo and bidirectional reflectance in the wavelength region of λ = 0.35-2.5 μm were made together with snow pit work on a flat snowfield in eastern Hokkaido, Japan. The effects of snow impurities, density, layer structure, and grain size attained by in situ and laboratory measurements were taken into account in snow models for which spectral albedos were calculated using a multiple-scattering model for the atmosphere-snow system. Comparisons of these theoretical albedos with measured ones suggest that the snow impurities were concentrated at the snow surface by dry fallout of atmospheric aerosols. The optically equivalent snow grain size was found to be of the order of a branch width of dendrites or of a dimension of narrower portion of broken crystals. This size was smaller than both the mean grain size and the effective grain size obtained from micrographs by image processing. The observational results for the bidirectional reflection distribution function (BRDF) normalized by the radiance at the nadir showed that the anisotropic reflection was very significant in the near-infrared region, especially for λ > 1.4 μm, while the visible normalized BRDF (NBRDF) patterns were relatively flat. Comparison of this result with two kinds of theoretical NBRDFs, where one having been calculated using single-scattering parameters by Mie theory and the other using the same parameters except for Henyey-Greenstein (HG) phase function obtained from the same asymmetry factor as in the Mie theory, showed that the observed NBRDF agreed with the theoretical one using the HG phase function rather than with that using the Mie phase function, while the albedos calculated with both phase functions agreed well with each other.

Original languageEnglish
Article number1999JD901122
Pages (from-to)10219-10236
Number of pages18
JournalJournal of Geophysical Research
Volume105
Issue numberD8
Publication statusPublished - Apr 27 2000
Externally publishedYes

Fingerprint

bidirectional reflectance
snow
Snow
albedo
reflectance
grain size
Mie theory
Mie scattering
Distribution functions
distribution functions
scattering
Impurities
Fallout
Atmospheric aerosols
impurities
fallout
Multiple scattering
nadir
Scattering parameters
dendrites

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geophysics
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Atmospheric Science
  • Astronomy and Astrophysics
  • Oceanography

Cite this

Aoki, T., Aoki, T., Fukabori, M., Hachikubo, A., Tachibana, Y., & Nishio, F. (2000). Effects of snow physical parameters on spectral albedo and bidirectional reflectance of snow surface. Journal of Geophysical Research, 105(D8), 10219-10236. [1999JD901122].

Effects of snow physical parameters on spectral albedo and bidirectional reflectance of snow surface. / Aoki, Teruo; Aoki, Tadao; Fukabori, Masashi; Hachikubo, Akihiro; Tachibana, Yoshihiro; Nishio, Fumihiko.

In: Journal of Geophysical Research, Vol. 105, No. D8, 1999JD901122, 27.04.2000, p. 10219-10236.

Research output: Contribution to journalArticle

Aoki, T, Aoki, T, Fukabori, M, Hachikubo, A, Tachibana, Y & Nishio, F 2000, 'Effects of snow physical parameters on spectral albedo and bidirectional reflectance of snow surface', Journal of Geophysical Research, vol. 105, no. D8, 1999JD901122, pp. 10219-10236.
Aoki T, Aoki T, Fukabori M, Hachikubo A, Tachibana Y, Nishio F. Effects of snow physical parameters on spectral albedo and bidirectional reflectance of snow surface. Journal of Geophysical Research. 2000 Apr 27;105(D8):10219-10236. 1999JD901122.
Aoki, Teruo ; Aoki, Tadao ; Fukabori, Masashi ; Hachikubo, Akihiro ; Tachibana, Yoshihiro ; Nishio, Fumihiko. / Effects of snow physical parameters on spectral albedo and bidirectional reflectance of snow surface. In: Journal of Geophysical Research. 2000 ; Vol. 105, No. D8. pp. 10219-10236.
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