The single-scattering properties of black carbon aggregates determined from the geometric-optics surface-wave approach and the T-matrix method
Artikel i vetenskaplig tidskrift, 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

Soot

Black carbon

Aggregated aerosol

T-matrix method

Geometric optics and surface wave

Författare

Y. Takano

University of California

K. N. Liou

University of California

Michael Kahnert

Chalmers, Rymd- och geovetenskap, Global miljömätteknik och modellering

P. Yang

Texas A&M University

Journal of Quantitative Spectroscopy and Radiative Transfer

0022-4073 (ISSN)

Vol. 125 51-56

Ämneskategorier

Astronomi, astrofysik och kosmologi

DOI

10.1016/j.jqsrt.2013.04.006

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Senast uppdaterat

2018-02-28