沙尘气溶胶粒子模型的线退偏比特性

发布时间：2018-05-22 13:18

  本文选题：散射 + 沙尘气溶胶　； 参考：《光学学报》2016年08期

【摘要】：利用离散偶极子近似法研究了旋转椭球体沙尘气溶胶粒子模型在尺度参数变化范围为0.1~23时(波长0.55μm对应有效半径为0.01~2μm)的线退偏比特性。通过分析比较不同轴半径比时线退偏比特性的差别,研究了粒子非球形性程度对单分散和多分散沙尘气溶胶粒子退偏比特性的影响。对单分散系,旋转椭球体沙尘气溶胶的线退偏比在瑞利散射区和米散射区随散射角的变化有不同的分布特征;在瑞利散射区,散射角分别为0°和180°的前后向散射方向,线退偏比较小,其值在1%的量级,而在散射角为90°附近的侧向,线退偏比有最大值,可达100%;在米散射区,线退偏比则无明显的极值分布,但有明显的后向增强;单分散沙尘粒子明显的非球形性特征,会增加在瑞利散射区的线退偏比,但却不会明显增加米散射区的线退偏比。而对多分散系,除了出现线退偏比最大值的侧向附近(80°~100°)之外,沙尘粒子非球形性特征越明显,其线退偏比越大。
[Abstract]:Using the discrete dipole approximation method, the linear depolarization ratio of the rotating ellipsoid dust aerosol particle model is studied in the range of 0.1 ~ 23:00 (the effective radius of 0.55 渭 m is 0.01g ~ 2 渭 m). By analyzing and comparing the characteristics of depolarization ratio of different axial radius ratio, the influence of particle non-sphericity on the depolarization ratio of monodisperse aerosol and polydisperse aerosol was studied. For monodisperse system, the linear depolarization ratio of rotating ellipsoid dust aerosol varies with the scattering angle in the Rayleigh scattering region and the meter scattering region, and in the Rayleigh scattering region, the scattering angle is 0 掳and 180 掳, respectively. The line depolarization ratio is small, its value is in the order of 1%, but in the lateral direction near 90 掳, the line depolarization ratio has the maximum value (up to 100), and in the meter scattering area, the line depolarization ratio has no obvious extreme value distribution, but has obvious backward enhancement. The obvious non-spherical character of monodisperse dust particles will increase the line depolarization ratio in Rayleigh scattering region, but it will not obviously increase the line depolarization ratio in rice scattering region. For the polydisperse system, the more obvious the non-spherical character of dust particles is, the larger the line depolarization ratio is, except the lateral direction near the maximum line depolarization ratio (80 掳/ 100 掳).
【作者单位】： 南京信息工程大学大气物理学院中国气象局气溶胶与云降水重点开放实验室;
【基金】：国家自然科学基金(41505127,21406189) 江苏省自然科学基金(BK20150901) 江苏省高校自然科学研究面上项目(15KJB170009) 南京信息工程大学人才启动经费项目(2015r002,2014r011)
【分类号】：X513;O436
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本文编号：1922221