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标题：A method to retrieve the spectral complex refractive index and single scattering optical properties of dust deposited in mountain snow
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作者：S. McKENZIE SKILES ; THOMAS PAINTER ; GREGORY S. OKIN 等
期刊名称：Journal of Glaciology
印刷版ISSN：0022-1430
电子版ISSN：1727-5652
出版年度：2017
卷号：63
期号：237
页码：133-147
DOI：10.1017/jog.2016.126
出版社：Cambridge University Press
摘要：ABSTRACT Dust deposition to snow can have regionally important climatic and hydrologic impacts resulting from direct reduction of surface albedo and indirectly from the initiation of snow albedo feedbacks. Modeling the radiative impacts of dust deposited in snow requires knowledge of the optical properties of both components. Here we present an inversion technique to retrieve the effective optical properties of dust deposited in mountain snow cover from measurements of hemispherical dust reflectance and particle size distributions using radiative transfer modeling. First, modeled reflectance is produced from single scattering properties modeled with Mie theory for a specified grain size distribution over a range of values for the imaginary part of the complex refractive index ( k = 0.00001–0.1). Then, a multi-step look-up table process is employed to retrieve k λ and single scattering optical properties by matching measured to modeled reflectance across the shortwave and near infrared. The real part of the complex refractive index, n , for dust aerosols ranges between 1.5 and 1.6 and a sensitivity analysis shows the method is relatively insensitive to the choice of n within this range, 1.525 was used here. Using the values retrieved by this method to update dust optical properties in a snow + aerosol radiative transfer model reduces errors in springtime albedo modeling by 50–70%.
关键词：energy balance; ice/atmosphere interactions; snow/ice surface processes; snow