In a moist atmosphere, the ageing process of aerosol can make the agglomerated soot particles compact, and cause them to be covered by a water coating. Based on the cluster‒cluster aggregation (CCA) algorithm, the models of chain-like soot with water coatings (Models A to E) were generated in this study. The superposition T-matrix method was employed to calculate their optical properties at 337, 550, 860, and 1060 nm wavelengths, with a focus on the impact of the soot inclusion morphology and water coating. Our results indicate that for particles with a looser soot-inclusion structure, there is a larger difference in the scattering phase function between them and the corresponding particles with a spherical soot core. The largest relative difference reached 51.8% at 337 nm. Impacted by the size parameter, the extinction cross section (C_ext), absorption cross section (C_abs), scattering cross section (C_sca), and single scattering albedo (SSA) increased as the water coating radius (R_water) increased and incidence wavelength decreased. The traditional assumption of a spherical soot core can cause the C_ext, C_abs, and C_sca to be overestimated, and cause the SSA to be underestimated when the incident wavelength is 337 nm. At 1060 nm, the assumption can cause the C_ext, C_abs, and C_sca to be underestimated, and lead the SSA to be overestimated. When the fractal dimension (D_f) of chain-like soot inclusion increased from 1.8 to 2.6, the SSA of the particles with a R_water of 0.20 μm significantly decreased from 0.784 to 0.764 at 1060 nm. Moreover, the thickness of the water coating had a stronger effect on the particles with chain-like soot inclusion at 337 nm than that at 1060 nm. For the 337 nm wavelength, the difference between the C_ext and C_sca in Model B when R_water = 0.30 and 0.20 μm was 0.588 and 0.587 μm², respectively. The differences were only 0.096 and 0.095 μm², respectively, for the 1060 nm wavelength. Based on the results calculated by the superposition T-matrix method, the ratios of P₂₂(Θ)/P₁₁(Θ) for chain-like soot with water coatings are not absolutely equal to 100%. When the D_f value of aggregated soot inclusion is a constant, P₂₂(Θ)/P₁₁(Θ) decreased as the volume ratio of soot inclusion to the water droplet increased. Therefore, the ratio of P₂₂(Θ)/P₁₁(Θ) can be potentially used as an optical indicator to describe the morphology of non-spherical and/or inhomogeneous particles (or inclusion) for internal aerosol, fog, or cloud particles. Generally, although the thickness of the water coating, to a large extent, dominates the optical properties of the internal mixtures, the morphology of aggregated soot inclusion is a key factor for causing uncertainties in optical parameters. This is especially so when the volume ratio of the soot inclusion and water droplet is large, and the structure of the soot inclusion is loose.

在潮湿的气氛中，气溶胶的老化过程会使团聚的烟尘颗粒致密，并使其被水涂层覆盖。基于簇簇聚集（CCA）算法，本研究建立了带有水涂层的链状烟灰模型（模型A至E）。叠加T矩阵法用于计算它们在337、550、860和1060 nm波长处的光学性能，重点是烟inclusion夹杂物形态和水涂层的影响。我们的结果表明，对于具有较松散的烟灰夹杂物结构的粒子，它们与具有球形烟灰芯的相应粒子之间的散射相位函数之间存在较大的差异。最大的相对差异在337 nm处达到51.8％。受尺寸参数影响，消光截面（C _ext），吸收截面（C _abs），散射截面（C _sca）和单散射反照率（SSA）随着水涂层半径（R _water）的增加和入射波长的减小而增加。传统的球形烟灰芯假设会导致C _ext，C _abs和C _sca被高估，而当入射波长为337 nm时，SSA被低估。在1060 nm处，该假设可能导致C _ext，C _abs和C _sca被低估，并导致SSA被高估。当链状烟灰夹杂物的分形维数（D _f）从1.8增加到2.6时，R_水为0.20μm的颗粒的SSA在1060 nm处从0.784显着降低到0.764。而且，水涂层的厚度对具有链状烟灰夹杂物的颗粒在337nm处的影响大于在1060nm处的影响。对于337nm的波长，所述的区别Ç _EXT和Ç _SCA在模型B时ř_水 = 0.30和0.20微米为0.588和0.587微米²， 分别。的差异是仅为0.096 0.095和微米²分别，对于1060nm的波长。基于通过叠加T矩阵法计算的结果，具有水涂层的链状烟灰的P ₂₂（Θ）/ P ₁₁（Θ）之比并非绝对等于100％。当聚集的烟灰夹杂物的D _f值恒定时，随着烟灰夹杂物与水滴的体积比增加，P ₂₂（Θ）/ P ₁₁（Θ）降低。因此，P ₂₂（Θ）/ P ₁₁（Θ）可潜在地用作光学指示器来描述非球形和/或不均匀的颗粒（或包含）用于内部气雾剂，雾，或云颗粒的形态。通常，尽管水涂层的厚度在很大程度上决定了内部混合物的光学性能，但聚集的烟inclusion夹杂物的形态是导致光学参数不确定的关键因素。当烟灰夹杂物与水滴的体积比大且烟灰夹杂物的结构疏松时，尤其如此。