灰霾天气对大气气溶胶光学特征的影响

Effect of Haze Weather on the Optical Characteristics of Atmospheric Aerosol

大气污染是我国当前最严峻的环境问题之一。近几年,城市灰霾天气发生频率急剧增加,灰霾天气在导致能见度降低的同时,对气溶胶的光学特征也有比较明显的影响。通过对灰霾期间气溶胶的光学特征的综述,介绍了灰霾天气时气溶胶光学厚度、Angstrom波长指数、单次散射反照率、散射系数等特征变化与研究进展。研究指出:灰霾天气多发生在冬季,从气溶胶质量谱中可以表明气溶胶中细颗粒物占的比重较大;同时气溶胶吸收与散射系数与PM2.5质量浓度有较好的相关性。灰霾天气发生时稳定的天气形势十分有利于颗粒物积累,使得气溶胶光学厚度增大,Angstrom波长增大,气溶胶粒子的单次反照率达到最大值,从而说明灰霾天气使得散射更强烈。

Air pollution is one of the most severe environmental problems in China. The frequency of urban hazy weather had a sharp increased in recent years. Haze weather not only reduced visibility but also had obvious influence on optical characteristics of atmospheric aerosol. Thorough the review of the optical characteristics in aerosol during haze weather, this article introduced the research progress and optical characteristic changes on aerosol, such as aerosol optical depth （AOD） , wavelength exponent of Angstrom, single scattering albedo （SSA） and scattering coefficient. The results indicated that haze usually occurred in winter, and fine particles in aerosol had larger proportion in mass spectra of aerosol, meanwhile, the absorption and scattering coefficient of aerosol presented good correlation with the mass concentration of PM2. 5- Stable weather was conducive to the accumulation of particles when hazy weather occurred, which resulted in the increase of AOD, wavelength exponent of Angstrom and the maximizing of SSA. Thus, the haze weather made the scattering more intense.