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[Size distribution properties of atmospheric aerosol particles during summer and autumn in Lanzhou]. | LitMetric

[Size distribution properties of atmospheric aerosol particles during summer and autumn in Lanzhou].

Huan Jing Ke Xue

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.

Published: March 2012

AI Article Synopsis

  • Atmospheric particle size distributions were measured in Lanzhou from August to October using an aerodynamic particle sizer, focusing on the range of 0.5 to 20 micrometers.
  • The study aimed to identify factors affecting these particle size distributions, revealing that fine particles (0.5-2.5 microm) make up the majority of the total concentrations.
  • Different particle size distributions were found, with coarse particles predominating on dusty days, while motor vehicle emissions influenced bimodal peaks in the distribution.

Article Abstract

Atmospheric particle size distributions (size range 0.5-20 microm) were measured using aerodynamic particle sizer (APS-3321) from August 1st to October 31st in Lanzhou. Variations of particle concentrations and properties of volume concentration distributions were analyzed through cluster analysis. The main objective of this study was to identify factors affecting the particle size distributions in Lanzhou. The hourly averaged particle number, surface area and volume concentrations are (108.1 +/- 92.2) cm(-3), (282.9 +/- 267.9) microm2 x cm(-3) and (92.2 +/- 127.3) microm3 x cm(-3), respectively. The number, surface area and volume concentrations of fine particles (0.5-2.5 microm) account for 98.7%, 73.8% and 52.9% of the total particle concentrations in 0.5-20 microm, respectively. The size distribution of number concentrations is unimodal with a peak at accumulation mode. The size distributions of surface area and volume concentrations are bimodal with peaks at accumulation mode and coarse mode, respectively. The size distributions of particle volume concentrations mainly have 7 clusters, indicating the effect of different sources and meteorological conditions. Coarse mode particles are dominant in particle volume size distributions affected by wind-borne dust and on dust days, while that affected by motor vehicle combustion emissions and traffic resuspended dust are characterized by bimodal with peaks at accumulation mode and coarse mode, respectively.

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