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Scattering of light by roughened Gaussian random particles
| Title: | Scattering of light by roughened Gaussian random particles |
| Authors: | Zubko, Evgenij Browse this author | | Muinonen, Karri Browse this author | | Shkuratov, Yuriy Browse this author | | Videen, Gorden Browse this author | | Nousiainen, Timo Browse this author |
| Issue Date: | 2007 |
| Publisher: | Elsevier |
| Journal Title: | Journal of Quantitative Spectroscopy and Radiative Transfer |
| Volume: | 106 |
| Issue: | 1-3 |
| Start Page: | 604 |
| End Page: | 615 |
| Publisher DOI: | 10.1016/j.jqsrt.2007.01.050 |
| Abstract: | We study the influence of surface roughness on light scattering by Gaussian-random-rough particles. Altogether, we consider four kinds of roughened surfaces: small-scale or large-scale roughening of the particle surface layers that are either thin or thick. We have performed computations for two realistic values of refractive indices corresponding to water ice (m=1.313+0i) and silicates (m=1.6+0.0005i). We vary the circumscribing-sphere size parameter xcs from 2 up to 12 in the case of silicate particles and up to 14 in the case of icy particles. For all sets of parameters, scattering of light by roughened particles is noticeably different from scattering by unroughened Gaussian particles. The parameter most sensitive to roughening is the degree of linear polarization of the scattered light when illuminated by unpolarized incident light. Except for the backscattering regime, roughening of particles increases the degree of polarization. Near backscattering, the dependence is more complicated. In the case of icy particles, roughening typically decreases the amplitude of the negative polarization surge; whereas, in the case of silicate particles, the dependence is non-monotonic: for xcs<10, roughening neutralizes the surge; whereas, for xcs=10 and 12, it makes the surge more pronounced. Particles with large spatial scale roughness produce less negative polarization than those with small-scale roughness. Particles with thin roughened surface layers generally produce larger negative polarization surges than those with thick layers. The intensity of scattered light is sensitive to roughening mostly near the backscattering although, for silicate particles with thick layers of roughened surface, we detect its influence also near forward scattering. In the case of icy particles, for xcs=12 and 14, thick-layer roughness amplifies the intensity of backscattering; whereas, for other cases, roughening results in decreased backscattering. Particles with thick roughened layers produce typically more gentle angular profiles of intensity near backscattering than the unroughened particles or particles with thin roughened layers. |
| Relation: | http://www.sciencedirect.com/science/journal/00224073 |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/28212 |
| Appears in Collections: | 低温科学研究所 (Institute of Low Temperature Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: Zubko, Evgenij S.
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