Key drivers to heterogeneity evolution of black carbon-containing particles in real atmosphere

Yan Peng; Li-Ming Cao; Jing Wei; Yong Cheng; Kuangyou Yu; Ke Du; Xiao-Feng Huang

doi:10.1016/j.scitotenv.2023.166394

Key drivers to heterogeneity evolution of black carbon-containing particles in real atmosphere

Sci Total Environ. 2023 Nov 1:897:166394. doi: 10.1016/j.scitotenv.2023.166394. Epub 2023 Aug 18.

Authors

Yan Peng¹, Li-Ming Cao², Jing Wei¹, Yong Cheng¹, Kuangyou Yu³, Ke Du⁴, Xiao-Feng Huang⁵

Affiliations

¹ Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
² Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China; Environmental Laboratory, PKU-HKUST Shenzhen-Hong Kong Institution, Shenzhen 518057, China.
³ Environmental Laboratory, PKU-HKUST Shenzhen-Hong Kong Institution, Shenzhen 518057, China; Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Canada. Electronic address: ykyoujoey@gmail.com.
⁴ Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Canada.
⁵ Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China. Electronic address: huangxf@pku.edu.cn.

PMID: 37597544
DOI: 10.1016/j.scitotenv.2023.166394

Abstract

The evolution of black carbon (BC) particles during atmospheric aging led to the complexity of their environmental and climate effect assessment. This study simultaneously measured the heterogeneous distribution of multi-level microphysical properties of BC-containing particles (i.e., BC mass concentration, coating amounts, and morphology) by a suite of state-of-the-art instruments, and investigated how atmospheric processing influence these heterogeneities. Our field measurements show that the mixing states of atmospheric BC-containing particles exhibit a clear dependence on BC core diameters. The particles with small BC core sizes (80-160 nm) are coated and reshaped more rapidly in real atmosphere, with coating-to-BC mass ratios (M_R) and non-spherical fractions of 5.1 ± 1.2 and 61 ± 19 %, respectively. Conversely, the particles with large core sizes (240-320 nm) are thinly coated and fractal, with M_R and non-spherical fractions of 4.0 ± 0.3 and 74 ± 15 %, respectively. Furthermore, primary emissions result in low heterogeneity in coating amount but great heterogeneity in morphology between BC-containing particles of different sizes, while photochemical processing would enhance heterogeneity in coating amount but weaken the heterogeneity in morphology. Overall, our field measurement of multi-level microphysical properties highlights that BC core size and atmospheric processing are the key factors that drive the heterogeneity evolution of BC-containing particles in real atmosphere.

Keywords: Aerosol microphysical properties; Atmospheric processes; BC-containing particles; Heterogeneity.