An observational study of atmospheric aerosol in Shijiazhuang area

Number concentration and size-distributions of aerosol particles were continuously measured at two locations in Shijiazhuang area (an urban site in Shijiazhuang and Zhaoxian, a suburb site), northern China, from May 11 to June 5, 2010, with an aerodynamic particle sizer spectrometer (APS). The spatial and temporal variations of aerosol properties were analyzed. The results show that fine-mode particles with diameters smaller than 1 μm dominate the number concentration at both sites, and the ratio of the concentration of particles in the size of 0.5-1μm account for 89.21% and 91.06%, respectively, of the total particles, which mainly came from polluted air emitted by industry and vehicle. However, the concentration of particles in the size of 2.5-20μm is higher in Shijiazhuang city than Zhaoxian. In addition, the diurnal variations of aerosol particles show multi peaks in Shijiazhuang, and a single peak in Zhaoxian. The variation of aerosol particle concentration may be related to the source and formation mechanism of fine particles.