气候变化领域集成服务门户(CCPortal): Modeling Optical Properties of Non-Cubical Sea-Salt Particles

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DOI	10.1029/2020JD033674
	Modeling Optical Properties of Non-Cubical Sea-Salt Particles
	Kanngießer F.; Kahnert M.
发表日期	2021
ISSN	2169897X
卷号	126 期号:4
英文摘要	Dry sodium chloride forms cubic crystals, while marine aerosol particles often display more or less irregular deviations from this ideal form. In this study, three non-ideal cuboidal and octahedral model geometries are investigated. Superellipsoids are tested as a model to simulate the linear backscatter depolarization ratio and the extinction-to-backscatter ratio. Gaussian random cubes as well as convex polyhedra are investigated as possible model candidates to quantify the error introduced by simplified model geometries, such as superellipsoids. Uncertainties in the real and imaginary part of the refractive index are studied, and their effect on the optical properties is compared to that caused by morphological variations. Optical calculations were performed at a wavelength of 532 nm using the discrete dipole approximation and the T-matrix method. The considered size range is representative for marine aerosol generated at low to moderate wind speeds. It is found that cuboidal superellipsoids predict depolarization and extinction-to-backscatter ratios that are consistent with observations. On the other hand, octahedral superellipsoids strongly overestimate the depolarization ratio. Gaussian random surface perturbations result in a positive shift of the depolarization ratio compared to cuboidal superellipsoids. By contrast, convex polyhedra yield results that more or less randomly scatter about those of regular cubes. Thus, convex polyhedra are a promising candidate for modeling random errors, while Gaussian random cubes are not. Uncertainties in the refractive index result in perturbations of the depolarization and extinction-to-backscatter ratio that are of comparable magnitude as those caused by perturbations of the geometry. © 2021. The Authors.
英文关键词	Aerosols; depolarization; light scattering; sea salt
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185496
作者单位	Department of Space, Earth and Environment, Chalmers University of Technology, Gothenburg, Sweden; Research Department, Swedish Meteorological and Hydrological Institute, Norrköping, Sweden
推荐引用方式 GB/T 7714	Kanngießer F.,Kahnert M.. Modeling Optical Properties of Non-Cubical Sea-Salt Particles[J],2021,126(4).
APA	Kanngießer F.,&Kahnert M..(2021).Modeling Optical Properties of Non-Cubical Sea-Salt Particles.Journal of Geophysical Research: Atmospheres,126(4).
MLA	Kanngießer F.,et al."Modeling Optical Properties of Non-Cubical Sea-Salt Particles".Journal of Geophysical Research: Atmospheres 126.4(2021).