Impact of Snow Grain Shape and Black Carbon–Snow Internal Mixing on Snow Optical Properties: Parameterizations for Climate Models
Impact of Snow Grain Shape and Black Carbon–Snow Internal Mixing on Snow Optical Properties: Parameterizations for Climate Models
复制标题
DOI：
10.1175/jcli-d-17-0300.1
复制
发表时间：
2017-11
影响因子：
4.9
通讯作者：
C. He;Y. Takano;K. Liou;P. Yang;Qinbin Li;Fei Chen
中科院分区：
文献类型：
--
作者：
C. He;Y. Takano;K. Liou;P. Yang;Qinbin Li;Fei Chen
基于几何光学表面波(GOS)计算，建立了一套适用于清洁雪和黑碳(BC)污染雪的光谱单次散射特性的参数化集，显式地解决了BC-雪的内部混合和各种雪粒形状。计算结果表明，与非球形颗粒相比，体积当量雪球的前向散射比非球形颗粒大20%，前向散射较强，特别是在波长<；1μm。相反，雪颗粒大小对波长<；1μm的不对称因子影响较小，而尺寸效应在较长波长影响较大。雪不对称因子被参数化为有效尺寸、纵横比和形状因子的函数，并与GOS计算显示出很好的一致性。根据GOS的计算，纯雪的单次散射反照率主要受颗粒大小的影响，而不是颗粒形状，颗粒越大，其值越高。积雪散落的煤..。
AbstractA set of parameterizations is developed for spectral single-scattering properties of clean and black carbon (BC)-contaminated snow based on geometric-optics surface wave (GOS) computations, which explicitly resolves BC–snow internal mixing and various snow grain shapes. GOS calculations show that, compared with nonspherical grains, volume-equivalent snow spheres show up to 20% larger asymmetry factors and hence stronger forward scattering, particularly at wavelengths <1 μm. In contrast, snow grain sizes have a rather small impact on the asymmetry factor at wavelengths <1 μm, whereas size effects are important at longer wavelengths. The snow asymmetry factor is parameterized as a function of effective size, aspect ratio, and shape factor and shows excellent agreement with GOS calculations. According to GOS calculations, the single-scattering coalbedo of pure snow is predominantly affected by grain sizes, rather than grain shapes, with higher values for larger grains. The snow single-scattering coal...