作者:Wu, Y (Wu, Yu)[ 1 ] ; Cheng, TH (Cheng, Tianhai)[ 1 ] ; Zheng, LJ (Zheng, Lijuan)[ 1 ] ; Chen, H (Chen, Hao)[ 1 ]

JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER

卷: 179  页: 139-148

DOI: 10.1016/j.jqsrt.2016.03.012

出版年: AUG 2016

摘要

The effects of soot aggregate quantities on the optical properties of their semi-external mixture with sulfate host particle were investigated. In this study, the individual soot containing mixtures were simulated as sulfate host point-contact attached to a specified amount of soot aggregates with the same monomer numbers and fractal parameters. The total numbers and volumes of soot monomers were also constant. Optical properties of this type of aerosol mixture were calculated using the numerically exact superposition T-matrix method (STM). The random-orientation averaging results indicated that the optical properties of the soot-containing mixtures may be influenced by the soot aggregate quantities. In these simulations, the absorption Angstrom exponent (AAE) values ranged from 0.9 to 1.1, which agree with the observations. The relative deviations of scattering Angstrom exponent (SAE) values between different numbers of soot aggregates attached to the surface of a sulfate host were upwards of similar to 11%. The results showed that the greater number of attached soot aggregates may lead to smaller SAE values in the soot-containing mixtures. For most cases of simulated mixtures, a more compact morphology of soot aggregates, larger soot monomer radii and smaller soot volume fractions (F-soot) may also generate smaller SAE values. Moreover, in the visible range, the simulated scattering cross sections of soot containing mixtures with two, three, four, and six soot aggregates (D-f=1.8) were similar to 5%, similar to 10%, similar to 15%, and similar to 30% larger than those with only one soot aggregate, respectively, on the condition that volumes of soot and sulfate are comparable. However, these relative deviations between different numbers of attached soot aggregates on the scattering cross sections of mixtures may be weakened for larger volume of non-absorbing sulfate particle (<5% for the cases of F-soot=1/10, sulfate volume is 9 times of soot). (C) 2016 Elsevier Ltd. All rights reserved.

通讯作者地址: Cheng, TH (通讯作者)

Chinese Acad Sci, State Key Lab Remote Sensing Sci, Inst Remote Sensing & Digital Earth, Beijing 100864, Peoples R China.

地址:

[ 1 ] Chinese Acad Sci, State Key Lab Remote Sensing Sci, Inst Remote Sensing & Digital Earth, Beijing 100864, Peoples R China