New particle formation (NPF) events have been recognized as an important process contributing to the cloud condensation nuclei (CCN) formation. In this study, measurement of NPF and predicted number concentrations of CCN using 冔-Kohler theory were analyzed to assess the contribution of NPF to CCN. The enhancement ratios (the ratio of CCN concentrations after to before NPF) were higher under high supersaturation (S). For example, it is about 30-50％ higher under S=0.86％ than under S=0.07％. The enhancement ratios were higher during the sulfur-poor NPF events with larger growth rates and exhibited similar seasonal variation as the growth rates with a larger value in summer than other seasons. Our results suggest that NPF events increase the CCN number concentrations by 0.4-6 times in the Megacity area of Beijing, growth rate is the key factor in the conversion of NPF to possible CCN, and organic species are implicated as the dominant contributor in facilitating the conversion of newly formed particles to possible CCN.
New particle formation Particle growth CCN
D.L. Yue Y. G. Gong A. Wiedensohler M. Hu R.Y. Zhang Z.J. Wu H. Su Z.B. Wang J.F. Peng L.Y.He X.F. Huang
State Key Joint Laboratory of Environmental Simulation and Pollution Control,College of Environmenta Research Institute of Chemical Defence,Beijing 102205,China Leibniz Institute for Tropospheric Research,Permoserstrasse 15,Leipzig 04318,Germany State Key Joint Laboratory of Environmental Simulation and Pollution Control,College of Environmenta State Key Joint Laboratory of Environmental Simulation and Pollution Control,College of Environmenta Biogeochemistry Department,Max Planck Institute for Chemistry,Becherweg 27,Mainz 55128,Germany Key Laboratory for Urban Habitat Environmental Science and Technology,Shenzhen Graduate School of Pe