TY - JOUR
T1 - The impact of surface roughness on scattering by realistically shaped wavelength-scale dust particles
AU - Kemppinen, Osku
AU - Nousiainen, Timo
AU - Lindqvist, Hannakaisa
PY - 2015/1/1
Y1 - 2015/1/1
N2 - The impact of dust particles surface roughness on scattering is investigated using model particles with realistic shapes based on stereogrammetry, up to size parameter 10. The surface roughness is introduced at the particle surfaces by randomly adding or subtracting volume elements in random surface locations with a Monte Carlo method, in such a way that the total number of volume elements comprising the particle is approximately conserved. Assuming an ensemble of randomly oriented particles, roughening seems to decrease the backscattered intensity, reduce the horizontal and vertical polarization, especially in the backscattering hemisphere, and increase diagonal and circular polarization at all scattering angles. The asymmetry parameter and single-scattering albedo are virtually unaffected, while lidar ratio and linear depolarization ratio are increased significantly, especially for large size parameters. These results are qualitatively similar for all particles and the impact of roughness on scattering is clearly related to the amount of roughening.
AB - The impact of dust particles surface roughness on scattering is investigated using model particles with realistic shapes based on stereogrammetry, up to size parameter 10. The surface roughness is introduced at the particle surfaces by randomly adding or subtracting volume elements in random surface locations with a Monte Carlo method, in such a way that the total number of volume elements comprising the particle is approximately conserved. Assuming an ensemble of randomly oriented particles, roughening seems to decrease the backscattered intensity, reduce the horizontal and vertical polarization, especially in the backscattering hemisphere, and increase diagonal and circular polarization at all scattering angles. The asymmetry parameter and single-scattering albedo are virtually unaffected, while lidar ratio and linear depolarization ratio are increased significantly, especially for large size parameters. These results are qualitatively similar for all particles and the impact of roughness on scattering is clearly related to the amount of roughening.
KW - Light scattering
KW - Mineral dust
KW - Surface roughness
UR - http://www.scopus.com/inward/record.url?scp=84908338750&partnerID=8YFLogxK
U2 - 10.1016/j.jqsrt.2014.05.024
DO - 10.1016/j.jqsrt.2014.05.024
M3 - Article
AN - SCOPUS:84908338750
SN - 0022-4073
VL - 150
SP - 55
EP - 67
JO - Journal of Quantitative Spectroscopy and Radiative Transfer
JF - Journal of Quantitative Spectroscopy and Radiative Transfer
ER -