Integral light-scattering and absorption characteristics of large, nonspherical particles

被引:27
作者
Kokhanovsky, AA
Macke, A
机构
[1] NATL SPACE DEV AGCY JAPAN,EARTH OBSERVAT RES CTR,MINATO KU,TOKYO 106,JAPAN
[2] NASA,GODDARD INST SPACE STUDIES,NEW YORK,NY 10025
来源
APPLIED OPTICS | 1997年 / 36卷 / 33期
关键词
D O I
10.1364/AO.36.008785
中图分类号
O43 [光学];
学科分类号
070207 ; 0803 ;
摘要
We obtain and analyze simple analytical formulas for asymmetry parameters and absorption cross sections of large, nonspherical particles. The formulas are based on the asymptotic properties of these characteristics at strong and weak absorption of radiation inside particles. The absorption cross section depends on parameter phi, which determines the value of the light-absorption cross section for weakly absorbing particles. It is larger for nonspherical scatterers. The asymmetry parameter depends on two parameters. The first is the asymmetry parameter g(0) of a nonspherical, transparent particle with the same shape as an absorbing one. The second parameter, beta, determines the strength of the influence of light absorption on the value of the asymmetry parameter. Parameter beta is larger for nonspherical particles. One can find these three parameters (phi, g(0), and beta) using a ray-tracing code (RTC) for nonabsorbing and weakly absorbing particles. The RTC can then be used to check the accuracy of the equations at any absorption for hexagonal cylinders and spheroids. It is found that the error of computing the absorption cross section and 1 - g (g is the asymmetry parameter) is less than 20% at the refractive index of particles n = 1.333. Values for asymmetry parameters of large, nonabsorbing, spheroidal particles with different aspect ratios are tabulated for the first time to our knowledge. They do not depend on the size of particles and can serve as an independent check of the accuracy of T-matrix codes for large parameters. (C) 1997 Optical Society of America.
引用
收藏
页码:8785 / 8790
页数:6
相关论文
共 21 条
[1]  
BROWN DJ, 1985, CHEM ENG RES DES, V63, P125
[2]   OPTICAL EFFICIENCIES OF LARGE PARTICLES OF ARBITRARY SHAPE AND ORIENTATION [J].
BRYANT, FD ;
LATIMER, P .
JOURNAL OF COLLOID AND INTERFACE SCIENCE, 1969, 30 (03) :291-&
[3]   LOCAL OPTICAL-PARAMETERS OF SPHERICAL POLYDISPERSIONS - SIMPLE APPROXIMATIONS [J].
KOKHANOVSKY, AA ;
ZEGE, EP .
APPLIED OPTICS, 1995, 34 (24) :5513-5519
[4]   SCATTERING OF LIGHT BY LARGE NONSPHERICAL PARTICLES - APPROXIMATION VERSUS T-MATRIX METHOD [J].
MACKE, A ;
MISHCHENKO, MI ;
MUINONEN, K ;
CARLSON, BE .
OPTICS LETTERS, 1995, 20 (19) :1934-1936
[5]   Applicability of regular particle shapes in light scattering calculations for atmospheric ice particles [J].
Macke, A ;
Mishchenko, MI .
APPLIED OPTICS, 1996, 35 (21) :4291-4296
[6]  
Macke A, 1996, J ATMOS SCI, V53, P2813, DOI 10.1175/1520-0469(1996)053<2813:SSPOAI>2.0.CO
[7]  
2
[8]   T-MATRIX COMPUTATIONS OF LIGHT-SCATTERING BY LARGE SPHEROIDAL PARTICLES [J].
MISHCHENKO, MI ;
TRAVIS, LD .
OPTICS COMMUNICATIONS, 1994, 109 (1-2) :16-21
[9]   LIGHT-SCATTERING BY POLYDISPERSE ROTATIONALLY SYMMETRICAL NONSPHERICAL PARTICLES - LINEAR-POLARIZATION [J].
MISHCHENKO, MI ;
TRAVIS, LD .
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER, 1994, 51 (05) :759-778
[10]   T-MATRIX COMPUTATIONS OF LIGHT SCATTERING BY NONSPHERICAL PARTICLES: A REVIEW (Reprinted from vol 55, pg 535-575, 1996) [J].
Mishchenko, Michael I. ;
Travis, Larry D. ;
Mackowski, Daniel W. .
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER, 2010, 111 (11) :1704-1744