Black carbon aggregates: A database for optical properties
Black carbon aggregates: A database for optical properties
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黑碳聚集体：光学特性数据库
DOI：
10.1016/j.jqsrt.2018.10.021
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发表时间：
2019-01-01
影响因子：
2.3
通讯作者：
Yung, Yuk L.
中科院分区：
文献类型：
--
作者：
Liu, Chao;Xu, Xiaofeng;Yung, Yuk L.
黑碳（BC）气溶胶作为太阳辐射的吸收剂在大气中发挥着重要作用，并且对全球变暖有重大贡献。 BC 的光学特性是直接辐射效应研究和 BC 特性遥感的基础。然而，由于BC颗粒复杂的聚集结构，对其光学性质的精确模拟受到限制且计算成本昂贵，而等效球形模型或近似方法很容易引入高达30%的相对误差。这项研究生成了一个综合数据库，可以有效、准确地计算聚合光学特性。该数据库涵盖了广泛的BC属性，包括聚集结构、折射率和颗粒尺寸（单体尺寸和单体数量）。精确的数值模型，即多球T矩阵方法，用于计算分形聚集体形式的BC簇的单散射特性。通过插值，数据库可以给出单体数量为1至3000、单体尺寸参数为0.05至0.5、折射率实部为1.2至2.0、虚部为0.2至1.0的聚集体的散射特性。对于单一散射特性，插值引起的相对误差远小于 1%。对BC气溶胶遥感和执行辐射效应计算感兴趣的用户可以公开使用预先计算的数据库和用于计算所需聚合光学特性的实现。 (C) 2018 Elsevier Ltd. 保留所有权利。
Black carbon (BC) aerosol plays an important role in the atmosphere as an absorber of solar radiation and contributes significantly to global warming. The optical properties of BC are fundamental for both direct radiative effect studies and remote sensing of BC properties. However, due to the complex aggregation structures of BC particles, accurate simulations of their optical properties are limited and computationally expensive, while equivalent spherical models or approximate methods could easily introduce relative errors up to 30%. This study generates a comprehensive database to calculate aggregate optical properties efficiently and accurately. The database covers a wide range of BC properties including aggregation structure, refractive index, and particle size (both monomer size and number of monomers). An accurate numerical model, i.e. the multiple-sphere T-matrix method, is used to calculate the single-scattering properties of BC clusters in the form of fractal aggregates. By interpolation, the database can be used to give the scattering properties of aggregates with monomer number from 1 up to 3000, monomer size parameter from 0.05 to 0.5, real part of refractive index from 1.2 to 2.0, and imaginary part from 0.2 to 1.0. The relative errors caused by the interpolation are much less than 1% for the single scattering properties. The pre-calculated database and the implementation used to calculate the required aggregate optical properties are publicly available for users interested in remote sensing of BC aerosols and performing radiative effect calculations. (C) 2018 Elsevier Ltd. All rights reserved.