Preprints
https://doi.org/10.5194/egusphere-2024-3298
https://doi.org/10.5194/egusphere-2024-3298
25 Nov 2024
 | 25 Nov 2024

Measurement report: size-resolved particle effective density measured by the AAC-SMPS and implications for chemical composition

Yao Song, Jing Wei, Wenlong Zhao, Jinmei Ding, Xiangyu Pei, Fei Zhang, Zhengning Xu, Ruifang Shi, Ya Wei, Lu Zhang, Lingling Jin, and Zhibin Wang

Abstract. The effective density (ρeff) is closely associated with the aging process and can serve as a tracer for chemical composition. Recently, studies investigating the effect of particle size on density have been limited. In this study, size-resolved ρeff was characterized with a tandem of an aerodynamic aerosol classifier (AAC) and a scanning mobility particle sizer (SMPS) system during one month of observation in Hangzhou. The results indicate that the ρeff values of the particles exhibit a unimodal distribution, with average values ranging from 1.47 g/cm3 to 1.63 g/cm3, increasing as the particle diameter increases. The diurnal variation is more pronounced for small particles (dae <350 nm), which generally exhibit lower density during the day and higher density at night. The relationship between ρeff and particle diameter varies under different pollution conditions due to differences in the chemical composition of the particles. additive explanations (SHAPs) revealed good relationships between ρeff and the bulk composition of particles with diameters smaller than 350 nm. Since the size-resolved chemical composition of particles is still challenging, a new method to investigate the size-resolved chemical composition was proposed, in which the size-resolved composition can be derived from the ρeff and fixed material density of secondary inorganic aerosols (SIAs), organic aerosols (OAs) and black carbon (BC).

Competing interests: At least one of the (co-)authors is a member of the editorial board of Atmospheric Chemistry and Physics.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
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This study investigates the size-resolved effective density (ρeff) of aerosol particles in...
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