Effects of humidity and temperature on the optical properties of wet sand

Abstract

Prediction method for the effect of air humidity and temperature on the optical properties of wet aerosol particles is a key research point on the atmospheric science, earth science, and so on. This paper firstly discussed the effect of moisture, salinity, and temperature on the particle's dielectric constant, and then analyzed the effect of these parameters on the electromagnetic scattering properties of wet sand. The results showed that with the increasing of the temperature, the real part of the permittivity of sand decreased, but its imaginary part increased, and the variation on the real part was much smaller than the imaginary part. With the increasing of the humidity, the equivalent permittivity of wet sand increased, and the difference of permittivity between the sand covered by pure water and the saline sand became obvious. In addition, the extinction efficiency, the scattering efficiency, the back-scattering efficiency and the asymmetry factor of dry sand particle are smaller than those of the wet sand, and with the increasing of the wavelength of electromagnetic wave, the scattering efficiency, the back-scattering efficiency and the asymmetry factor of the dry and wet sand particle are all exponential increased, but the extinction efficiency showed a different changing rule.