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Insights into vertical differences of particle number size distributions in winter in Beijing, China
- Source :
- SCIENCE OF THE TOTAL ENVIRONMENT
- Publication Year :
- 2022
-
Abstract
- Particle number size distribution (PNSD) is of importance for understanding the mechanisms of particle growth, haze formation and climate impacts. However, the measurements of PNSD aloft in megacities are very limited. Here we report the first simultaneous winter measurements of size-resolved particle number concentrations along with collocated gaseous species and aerosol composition at ground level and 260 m in Beijing. Our study showed that the vertical differences of particle number concentrations between ground level and aloft varied significantly as a function of particle size throughout the study. Further analysis illustrated the impacts of boundary dynamics and meteorological conditions on the vertical differences of PNSD. In particular, the temperature and relative humidity inversions were one of the most important factors by decoupling the boundary layer into different sources and processes. Positive matrix factorization analysis identified six sources of PNSD at both ground level and city aloft. The local source emissions dominantly contributed to Aitken-mode particles, and showed the largest vertical gradients in the city. Comparatively, the regional particles were highly correlated between ground level and city aloft, and the vertical differences were relatively stable throughout the day. Our results point to-wards a complex vertical evolution of PNSD due to the changes in boundary layer dynamics, meteorological con-ditions, sources, and processes in megacities. (c) 2021 Elsevier B.V. All rights reserved.
- Subjects :
- China
Environmental Engineering
Haze
010504 meteorology & atmospheric sciences
Particle number
010501 environmental sciences
Atmospheric sciences
01 natural sciences
114 Physical sciences
Beijing
Environmental Chemistry
Relative humidity
Particle Size
Waste Management and Disposal
0105 earth and related environmental sciences
Aerosols
Air Pollutants
Decoupling (cosmology)
Pollution
Boundary layer
13. Climate action
Particle growth
Environmental science
Particulate Matter
Particle size
Seasons
Environmental Monitoring
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- SCIENCE OF THE TOTAL ENVIRONMENT
- Accession number :
- edsair.doi.dedup.....92046b3742ab8a3db762ab97113818b6