Volume 12, No. 6, December 2012, Pages 1362-1372 PDF(5.12 MB)
Aerosol Size Spectra and Particle Formation Events at Urban Shanghai in Eastern China
Jianfei Du1,2, Tiantao Cheng1, Min Zhang3, Jianmin Chen1, Qianshan He2, Xuemei Wang1, Renjian Zhang4, Jun Tao5, Guanghan Huang1, Xiang Li1, Shuping Zha1
1 Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China
2 Shanghai Meteorological Bureau, Shanghai 200030, China
3 Key Laboratory of Data Analysis and Applications, The First Institute of Oceanography, State Oceanic Administration, Qingdao, 266061, China
4 Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
5 South China Institute of Environmental Sciences, Guangzhou 510655, China
Aerosol number size distributions between 10 nm and 10 µm were measured from October 2008 to February 2009 in Shanghai, China. The average particle number, surface and volume concentrations were 1.3 × 104 1/cm3, 6.4 × 102 µm2/cm3 and 64 µm3/cm3, respectively. Aitken particles dominated the total number of particles, and accumulated particles were the greatest contributor to particle surface area. Particle number size distributions could be characterized by multi-lognormal functions. The average number size distributions of aerosols revealed a clear diurnal pattern of two peaks within 30–60 nm corresponding to the morning and afternoon traffic rush hours. All size particles had two peaks in mean number concentrations during the rush hours, and 10–20 nm and 20–50 nm particles had one additional peak in late morning. The new particle formation events were found on four days out of 73. The apparent formation rates varied from 0.2 to 0.5 cm3/s, and the growth rates of newly formed particles were 3.3–5.5 nm/h. Overall, the new particle formation events had a significant impact on particle size spectra in the nucleation and Atiken modes, but insignificant effects on particle surface and volume concentrations.
Aerosol size distribution; Number concentration; Particle formation event.