The choice of optical properties of soot particles for description of solar radiation absorption in the atmosphere and on the Earth's surface
E.V. Gurentsov, A.V. Eremin, R.N. Kolotushkin
Joint Institute for High Temperatures of Russian Academy of Sciences, Moscow, Russia
Keywords: soot particles, absorption of solar radiation, refractive index function, average size of soot particles
Abstract
New data are presented on the dependence of the function of the refractive index of soot particles on their average size in the visible and near-IR spectral regions found by the method of laser-induced incandescence. The sunlight absorption by soot aerosols is currently calculated with a value of the refractive index function of about 0.2 at a wavelength of 550 nm regardless of the origin of soot particles and their variability. The new data confirm the dependence of the optical properties of soot on the size of particles and conditions of their formation, which is related to the degree of their graphitization. It is shown that the solar radiation absorption by soot aerosol can double as compared to the commonly accepted values if taking into account the particle size distribution.
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