Measurements and analysis of urban aerosol

Atmospheric aerosol particles absorb and scatter both the incoming solar radiation and the emitted infrared energy from the Earth. They are also involved in the formation processes of cloud, fog and haze. An increase in the concentration of aerosol in some urban regions caused by human activity has a significant impact on the environmental quality of the cities, which makes the air turbid with lower visibility and the atmospheric opto-chemistry reaction faster. To increase understanding of the urban aerosol a measurement program was conducted in Beijing and Hefei in 1998, in which a lidar of MPL, optical particle counter of model DLJ-92, and an 8-wavelength sun-photometer of model DFT-3 were operated. This paper introduces the measurement methods and analyzes the characteristics of urban aerosol in Beijing and Hefei, China.