应用T矩阵法对大气灰霾简单非球形粒子散射特性的计算与分析

Abstract

Scattering characteristics of atmospheric haze particles, main ingredients particles of PM2.5 were studied, ammonium sulfate and carbonaceous aerosol particles were taken as typical example. By the T matrix algorithm, the non-spherical particles of ammonium sulfate and carbonaceous aerosol particles were analyzed, including the ellipsoid particles(major to minor axis ratio, a/b=1/2,1/3,2/1), cylindrical particles(diameter to length ratio, D/L=1/2,1/3,1/1,2/1) and chebyshev particles(polynomial n=2,deformation parameter =-0.1,0.1). Corresponding scattering, absorption and extinction efficiency factor changing with the shape and the size parameter were given. Study results show that, for ammonium sulfate particles, if size parameter was less than 1, efficiency factor tendencies of different shape particles were similar, if size parameter was greater than 1, scattering and extinction efficiency factor increased with the size parameter and then decreased with oscillation, and absorption of ammonium sulfate particles were weak. For carbonaceous aerosol particles, if size parameter was less than 2, efficiency factor tendencies of different shape particles were similar, if size parameter was greater than 2, efficiency factor increased with the size parameter and soon decreased slowly and smoothly, and carbonaceous aerosol particles had strong absorption of light. The analyzing results can be used for optical monitoring and detection of haze particle,improve the ability of science and technology supported environmental pollution prevention.