铜绿微囊藻吸收和散射特性两层球形模型模拟

Simulating the Light Absorption and Scattering Properties of Microcystis Aeruginosa Using a Two-Layered Spherical Geometry

铜绿微囊藻是我国内陆富营养化湖泊蓝藻水华的主要藻种。将铜绿微囊藻抽象为由细胞质和叶绿体构成的两层球形模型,通过循环迭代的方式确定两层球形模型中叶绿体的体积比例及其折射率的中心值,结合Kramers-Kronig关系最终确定两层球形模型细胞质及叶绿体的复折射率,通过Aden-Kerker理论结合粒径分布情况模拟出其吸收和散射效率光谱。对比模拟结果与实验结果发现:该模型估算得到的散射光谱与实验的散射光谱之间误差为3.4%,吸收效率误差为4.3%,在后向散射模拟实验中,相比均匀球形模型,两层球形模型表现出较好的优越性。

Microcystis aeruginosa is the main species during alga bloom in inland eutrophic lakes. We consider that Microcystis aeruginosa consists of cytoplasm and chloroplast for simulating optical characteristics based on the two-layered spherical geometry. The central real refractive index value and volume ratio of chloroplast are calculated through the method of loop iterations. Meanwhile, based on the Kramers-Kronig relationship, the refractive index value of cytoplasm and chloroplast could be obtained. Finally, the absorption and scattering properties of Microcystis aeruginosa are simulated using the Aden-Kerker theory and particle size distribution. The results show that the relative errors between modeled and measured scattering and absorption efficiency factors are 3.4% and 4.3%, respectively. In comparison with the simulation based on Mie theory, the two-layered spherical model shows a better simulation accuracy of the backscattering properties.