Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 5.509 IF 5.509
  • IF 5-year value: 5.689 IF 5-year 5.689
  • CiteScore value: 5.44 CiteScore 5.44
  • SNIP value: 1.519 SNIP 1.519
  • SJR value: 3.032 SJR 3.032
  • IPP value: 5.37 IPP 5.37
  • h5-index value: 86 h5-index 86
  • Scimago H index value: 161 Scimago H index 161
Volume 16, issue 4
Atmos. Chem. Phys., 16, 2641-2657, 2016
https://doi.org/10.5194/acp-16-2641-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Atmos. Chem. Phys., 16, 2641-2657, 2016
https://doi.org/10.5194/acp-16-2641-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 03 Mar 2016

Research article | 03 Mar 2016

Nucleation and growth of sub-3 nm particles in the polluted urban atmosphere of a megacity in China

Huan Yu1,2,3, Luyu Zhou1, Liang Dai1, Wenchao Shen1, Wei Dai1, Jun Zheng1,2,3, Yan Ma1,2,3, and Mindong Chen1,2,3 Huan Yu et al.
  • 1School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, China
  • 2Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science and Technology, Nanjing, China
  • 3Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing, China

Abstract. Particle size distribution down to 1.4 nm was measured in the urban atmosphere of Nanjing, China, in spring, summer, and winter during 2014–2015. Sub-3 nm particle event, which is equivalent to nucleation event, occurred on 42 out of total 90 observation days, but new particles could grow to cloud condensation nuclei (CCN)-active sizes on only 9 days. In summer, infrequent nucleation was limited by both unfavorable meteorological conditions (high temperature and relative humidity – RH) and reduced anthropogenic precursor availability due to strict emission control measures during the 2014 Youth Olympic Games in Nanjing. The limiting factors for nucleation in winter and spring were meteorological conditions (radiation, temperature, and RH) and condensation sink, but for the further growth of sub-3 nm particles to CCN-active sizes, anthropogenic precursors again became limiting factors. Nucleation events were strong in the polluted urban atmosphere. Initial J1.4 at the onset and peak J1.4 at the noontime could be up to 2.1 × 102 and 2.5 × 103 cm−3 s−1, respectively, during the eight nucleation events selected from different seasons. Time-dependent J1.4 usually showed good linear correlations with a sulfuric acid proxy for every single event (R2 = 0.56–0.86, excluding a day with significant nocturnal nucleation), but the correlation among all eight events deteriorated (R2 = 0.17) due to temperature or season change. We observed that new particle growth rate (GR) did not increase monotonically with particle size, but had a local maximum up to 25 nm h−1 between 1 and 3 nm. The existence of local maxima GR in sub-3 nm size range, though sensitive to measurement uncertainties, gives new insight into cluster dynamics in polluted environments. In this study such growth rate behavior was interpreted as the solvation effect of organic activating vapor in newly formed inorganic nuclei.

Publications Copernicus
Download
Short summary
New particle formation is an important source of atmospheric aerosols. We conducted size- and time-dependent nucleation rate and growth rate measurements of sub-3 nm particles in the urban atmosphere. We observed that growth rate could be very high between 1 and 3 nm and did not increase monotonically with particle size. This was interpreted as the solvation effect of organic vapor in inorganic nuclei. The growth rate behavior gives new insight into cluster dynamics in polluted environments.
New particle formation is an important source of atmospheric aerosols. We conducted size- and...
Citation
Share