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DOI	10.5194/acp-15-12159-2015
	What is the real role of iron oxides in the optical properties of dust aerosols?
	Zhang, X. L.; Wu, G. J.; Zhang, C. L.; Xu, T. L.; Zhou, Q. Q.
通讯作者	Zhang, XL (通讯作者)
发表日期	2015
ISSN	1680-7316
EISSN	1680-7324
起始页码	12159
结束页码	12177
卷号	15 期号:21
英文摘要	Iron oxide compounds constitute an important component of mineral dust aerosols. Several previous studies have shown that these minerals are strong absorbers at visible wavelengths and thus that they play a critical role in the overall climate perturbation caused by dust aerosols. When compiling a database of complex refractive indices of possible mineral species of iron oxides to study their optical properties, we found that uniformly continuous optical constants for a single type of iron oxide in the wavelength range between 0.2 and 50 mu m are very scarce, and that the use of hematite to represent all molecular or mineral iron-oxides types is a popular hypothesis. However, the crucial problem is that three continuous data sets for complex refractive indices of hematite are employed in climate models, but there are significant differences between them. Thus, the real role of iron oxides in the optical properties of dust aerosols becomes a key scientific question, and we address this problem by considering different refractive indices, size distributions and more logical weight fractions and mixing states of hematite. Based on the microscopic observations, a semi-external mixture that employs an external mixture between Fe aggregates and other minerals and partly internal mixing between iron oxides and aluminosilicate particles is advised as the optimal approximation. The simulations demonstrate that hematite with a spectral refractive index from Longtin et al. (1988) shows approximately equal absorbing capacity to the mineral illite over the whole wavelength region from 0.55 to 2.5 mu m, and only enhances the optical absorption of aerosol mixture at lambda < 0.55 mu m. Using the data set from Querry (1985) may overestimate the optical absorption of hematite at both visible and near-infrared wavelengths. More laboratory measurements of the refractive index of iron oxides, especially for hematite and goethite in the visible spectrum, should therefore be taken into account when assessing the effect of mineral dust on climate forcing.
关键词	SAHARAN-MINERAL-DUST COMPLEX REFRACTIVE-INDEX IN-SITU MEASUREMENTS ATMOSPHERIC DUST LIGHT-SCATTERING BLACK CARBON DESERT DUST CHEMICAL-COMPOSITION RADIATIVE PROPERTIES SIZE DISTRIBUTIONS
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS类目	Environmental Sciences ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000365329000003
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/258509
推荐引用方式 GB/T 7714	Zhang, X. L.,Wu, G. J.,Zhang, C. L.,et al. What is the real role of iron oxides in the optical properties of dust aerosols?[J]. 中国科学院青藏高原研究所,2015,15(21).
APA	Zhang, X. L.,Wu, G. J.,Zhang, C. L.,Xu, T. L.,&Zhou, Q. Q..(2015).What is the real role of iron oxides in the optical properties of dust aerosols?.ATMOSPHERIC CHEMISTRY AND PHYSICS,15(21).
MLA	Zhang, X. L.,et al."What is the real role of iron oxides in the optical properties of dust aerosols?".ATMOSPHERIC CHEMISTRY AND PHYSICS 15.21(2015).