| The rapid economic expansion, accelerating the urbanization process and increasing the number of cars has led to worsening aerosol pollution and increasing haze phenomena. Four especially serious haze pollution areas, Beijing and tianjin tang China, Sichuan basin, the Yangtze and the pearl river delta, haze pollutions increased rapidly. Such as Beijing, Shanghai, Guangzhou and other places, the haze days were more than a third of all the year round, some even more than half a year. The haze atmospheric turbidity phenomenon is difficult to get effective control, because of a fine aerosol particles sedimentation, small volume and light weight is not easily remove, which has a great impact on the survival of human and the earth's climate environment. Thus, the study of high concentration of aerosol, such as the haze and dust, is attracting great importance of scientists.Research progress on scattering of transfer properties of high concentration of aerosol are introduced, such as haze, dust. Such four aspects are emphasizes:(1) physical-optical properties of atmospheric aerosol;(2) effects of relative humidity on aerosol scattering;(3) the polarization reflection characteristic;(4) multiple scattering between ground and atmosphere, the vector radioactive transfer modeling in high concentration of aerosol. At the same time, extinction effect of atmospheric aerosol directly affects the atmospheric visibility by scattering and absorption of light, related scattering theory are: Rayleigh scattering and Mie scattering, the T matrix and DDA theory of non-spherical particles and so on.The concentration of water soluble ion SO42-?NO3- and NH4+ in fine particles(D< 2.5?m) in haze is more higher than the normal weather, which are the main chemical composition of PM2.5 and mainly exist in the form of ammonium sulfate and ammonium nitrate. These high concentrations of ammonium salt is helpful to generate secondary particles, worsen the atmospheric visibility and occur haze phenomena, and the haze particles are acid, in addition, elements and organic carbon made huge contributions in the formation of haze. And geographical and pollution source will make a big difference of PM2.5 chemical composition, now known as the main composition is sulfate, ammonium sulfate, ammonium nitrate and the carbon aerosols(including elements and organic carbon), etc.Therefore, based on the above four kinds of particles as the main research object, with Mie theory and the T matrix theory to study the corresponding components scattering phase function of a single spherical particle and non-spherical particle, the non- spherical particles mainly includes the ellipsoid particle(axle than 1/2, 1/3, 2/1), cylindrical particle(diameter and length ratio of 1/2, 1/3, 2/1) and chebyshev particle(n=2 chebyshev polynomials, deformation parameters of-0.1 and 0.1).The scattering, absorption and extinction efficiency factor change with the size parameter, and the scattering phase function change with the scattering angle of the above four components are analyzed and calculated. Result shows that ammonium sulfate, sulfuric acid and ammonium nitrate particles has strong-scattering effect, while the carbonaceous aerosol particles showed a greater absorption effect. Finally, by comparing scattering phase functions of different particles with the different radius, shows the phase function of particle is more sensitive to size and complex refractive index, The results of this thesis can be used for optical remote sensing monitoring of air pollution. |
PDF Full Text Request