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Modeling Optical Properties of Mineral Aerosol Particles by Using Nonsymmetric HexahedraWe explore the use of nonsymmetric geometries to simulate the single-scattering properties of airborne dust particles with complicated morphologies. Specifically, the shapes of irregular dust particles are assumed to be nonsymmetric hexahedra defined by using the Monte Carlo method. A combination of the discrete dipole approximation method and an improved geometric optics method is employed to compute the single-scattering properties of dust particles for size parameters ranging from 0.5 to 3000. The primary optical effect of eliminating the geometric symmetry of regular hexahedra is to smooth the scattering features in the phase function and to decrease the backscatter. The optical properties of the nonsymmetric hexahedra are used to mimic the laboratory measurements. It is demonstrated that a relatively close agreement can be achieved by using only one shape of nonsymmetric hexahedra. The agreement between the theoretical results and their measurement counterparts can be further improved by using a mixture of nonsymmetric hexahedra. It is also shown that the hexahedron model is much more appropriate than the "equivalent sphere" model for simulating the optical properties of dust particles, particularly, in the case of the elements of the phase matrix that associated with the polarization state of scattered light.
Document ID
20110007296
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Bi, Lei
(Texas A&M Univ. College Station, TX, United States)
Yang, Ping
(Texas A&M Univ. College Station, TX, United States)
Kattawar, George W.
(Texas A&M Univ. College Station, TX, United States)
Kahn, Ralph
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 25, 2013
Publication Date
January 12, 2010
Publication Information
Publication: Applied Optics
Volume: 49
Issue: 3
Subject Category
Optics
Funding Number(s)
CONTRACT_GRANT: NSF AMT-0803779
CONTRACT_GRANT: ONR N00014-06-1-0069
Distribution Limits
Public
Copyright
Other

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