The single-scattering properties of black carbon aggregates determined from the geometric-optics surface-wave approach and the T-matrix method
Journal article, 2013

The single-scattering properties of eight black carbon (BC, soot) fractal aggregates, composed of primary spheres from 7 to 600, computed by the geometric-optics surface-wave (GOS) approach coupled with the Rayleigh-Gans-Debye (RGD) adjustment for size parameters smaller than approximately 2, are compared with those determined from the superposition T-matrix method. We show that under the condition of random orientation, the results from GOS/RGD are in general agreement with those from T-matrix in terms of the extinction and absorption cross-sections, the single-scattering co-albedo, and the asymmetry factor. When compared with the specific absorption (m(2)/g) measured in the laboratory, we illustrate that using the observed radii of primary spheres ranging from 3.3 to 25 nm, the theoretical values determined from GOS/RGD for primary sphere numbers of 100-600 are within the range of measured values. The GOS approach can be effectively applied to aggregates composed of a large number of primary spheres (e.g., > 6000) and large size parameters (>> 2) in terms of computational efforts.

Rayleigh-Gans-Debye scattering


Black carbon

Aggregated aerosol

T-matrix method

Geometric optics and surface wave


Y. Takano

University of California

K. N. Liou

University of California

Michael Kahnert

Chalmers, Earth and Space Sciences, Global Environmental Measurements and Modelling

P. Yang

Texas A&M University

Journal of Quantitative Spectroscopy and Radiative Transfer

0022-4073 (ISSN)

Vol. 125 51-56

Subject Categories

Astronomy, Astrophysics and Cosmology



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