The Study of UV Scattering Polarization Properties of Spherical Particles of Haze

With the rapid development of economy and society in our country, atmospheric haze has become a prominent environmental issue. Measuring haze particles is also important. Polarized ultraviolet light is scattered by atmospheric haze particles, the changes of scattered light polarization state(Stokes vector and the degree of polarization) in atmospheric haze can reflect the physical properties of the particles (particle size and the complex refractive index, etc.). Based on Mie scattering theory, line-of-sight and non-line-of-sight of a single UV scattering model is established. On one hand, the effects of the physical properties of the single and chain-structure spherical particles for the UV light polarization properties are studied. On the other hand, based on Monte Carlo Simulation, the impacts of haze particle concentration on polarization state at a fixed particle size distribution are discussed. The simulation results show that: with the particle size of single spherical increasing, the scattered light intensity in Stokes vector (Is) is significantly enhanced. Is shows a trend of first increase then decrease with the increase of the complex refractive index’s imaginary part. The degree of polarization is constantly increasing with the increase of the complex refractive index’s imaginary part and the imaginary part of the complex refractive index is small, the degree of polarization trend of fast increase. With the concentration of particles in haze increasing when the distribution of particle size is a fixed value, haze particles scattering coefficient, extinction coefficient and absorption coefficient showed a linear increase, while Is is reduced after the first increases. For chain-structure spherical particles, with the increase of the number of particles, Is shows a tendency to increase. As the same time, degrees of polarization distinguish whether the chain-structure spherical particles are made up by the same spherical particle. In the chain-structure consisted of same spherical particles, Is increases linearly with the increase of the number of particles and the degree of polarization does not change. The Is under the chain-structure consisted of different spherical particles can distinguish particles’ physical properties according to the changing trend of scattering light polarization state.