1 Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
2 Key Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
3 The College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
Cite this article: Zhao, S., Yu, Y., Yin, D. and He, J. (2017). Effective Density of Submicron Aerosol Particles in a Typical Valley City, Western China.
Aerosol Air Qual. Res.
17: 1-13. https://doi.org/10.4209/aaqr.2015.11.0641
Effects of weather conditions on particle density were evaluated.
Density for submicron particles ranged from 1.3 g cm–3 to 1.6 g cm–3 in Lanzhou.
Particle density increased by 0.1 g cm–3 due to rain.
Mean particle density was 1.19 g cm–3 during firework displays.
Evolution of effective density of submicron aerosol particles and effects of firework displays and weather conditions on particle effective density in a typical valley city in northwestern China were evaluated by fitting the APS data to the SMPS data in the overlapping size region of the two instruments during September 2012 to August 2013. The monthly mean effective densities for submicron aerosol particles were found to vary from 1.3 g cm–3 to 1.6 g cm–3 depending on the month of year. In addition, the ranges of average submicron particle effective density were different on workdays, Saturdays, Sundays and holidays in different seasons with minimums in the morning and afternoon, especially observed in morning rush hours of weekdays, and a maximum during midday. The precipitation and strong wind resulted in particle effective densities increased by 0.1 g cm–3 and 0.08 g cm–3, respectively, while effective densities of submicron aerosol particles decreased by 0.21 g cm–3 due to the effect of dust. During the periods mainly affected by firework displays, the effective densities of submicron aerosol particles were 1.19 g cm–3, which was much lower than those for firework-unaffected days, and the submicron particle effective densities decreased by 0.29 g cm–3 due to firework displays.
Keywords: Submicron particle; Effective density; Valley city; Lanzhou