HR: 17:20h
AN: C42C-06    [PDF]
TI: Comparison of simulated spectral bidirectional reflectance function of snow-covered austral summer sea ice with measurements
AU: * Li, S
EM: sli@asf.alaska.edu
AF: University of Alaska Fairbanks, 903 Koyukuk Drive, P.O. Box 757320, Fairbanks, AK 99775-7320 United States
AU: Zhou, X
EM: xzhou@nmt.edu
AF: New Mexico Tech, 801 Leroy Place, Socorro, NM 87801 United States
AB: The bidirectional reflectance distribution function (BRDF) is an important geophysical variable that provides patterns of surface directional reflectance due to direct beam incidence. Information of BRF is required to derive surface albedo from remote sensing data sets. Also, albedo under various conditions can be evaluated by integration of BRFs. Knowledge of BRF of snow covered sea ice surface is especially important because sea ice exerts a strong positive feedback effect on the surface energy budget, and snow covered sea ice exhibits a strong anisotropic pattern when the solar incidence angle is large. However, it is difficult to obtain a complete data set of snow-covered sea ice surface BRDF through field measurement because of the general paucity of clear sky conditions and the narrow range of solar incidence angles that occur during measurement. The information gap can be filled through validation of the modeled results from radiative transfer simulations. We performed a simulation of snow covered sea ice surface BRF using a multi-layered azimuth- and zenith-dependent plane parallel radiative transfer code. Combined with Mie scattering algorithm, the code takes the measured snow grain sizes, densities and thicknesses of individual layers as input, and generates snow-covered sea ice surface spectral BRF as output. The simulated surface spectral BRF is then compared with measurements. The discrepancies between the model simulation and measurements are analyzed and causes inferred.
UR: http://www.asf.alaska.edu/~sli
DE: 1640 Remote sensing
DE: 1863 Snow and ice (1827)
DE: 3359 Radiative processes
DE: 4540 Ice mechanics and air/sea/ice exchange processes
SC: Cryosphere [C]
MN: 2003 Fall Meeting