Light scattering by particles with small-scale surface roughness: comparison of four classes of model geometries
Artikel i vetenskaplig tidskrift, 2012

We compare four different model geometries for particles with small-scale surface roughness. The geometries are based on regular and stochastic surface perturbations, as well as on 2D- and 3D-roughness models. We further compare T-matrix and discrete dipole computations. Particle size parameters of 5 and 50 are considered, as well as refractive indices of 1.6 + 0.0005i and 3 +0.1i. The effect of small-scale surface roughness on the intensity and polarisation of the scattered light strongly depends on the size parameter and refractive index. In general, 2D surface roughness models predict stronger effects than 3D models. Stochastic surface roughness models tend to predict the strongest depolarising effects, while regular surface roughness models can have a stronger effect on the angular distribution of the scattered intensity. Computations with the discrete dipole approximation only cover a limited range of size parameters. T-matrix computations allow us to significantly extend that range, but at the price of restricting the model particles to symmetric surface perturbations with small amplitudes.

Lidar

Surface roughness

T-matrix

Scattering

Aerosols

Mineral dust

Författare

Michael Kahnert

Chalmers, Rymd- och geovetenskap, Global miljömätteknik och modellering

T. Nousiainen

Helsingin Yliopisto

Manu Anna Thomas

SMHI

Jani Tyynelä

Helsingin Yliopisto

Journal of Quantitative Spectroscopy and Radiative Transfer

0022-4073 (ISSN)

Vol. 113 18 2356-2367

Ämneskategorier

Meteorologi och atmosfärforskning

Astronomi, astrofysik och kosmologi

Atom- och molekylfysik och optik

Fundament

Grundläggande vetenskaper

DOI

10.1016/j.jqsrt.2012.03.017

Mer information

Senast uppdaterat

2018-07-04