First long-term study of particle number size distributions and new particle formation events of regional aerosol in the North China Plain 1Key Laboratory for Atmospheric Chemistry of CMA, Center for Atmosphere Watch and Services, Chinese Academy of Meteorological Sciences, Beijing 100081, China
18 Feb 2011
2Graduate University of Chinese Academy of Sciences, Beijing 100049, China
3Leibniz Institute for Tropospheric Research, 04318 Leipzig, Germany
4Shangdianzi Regional GAW station, Research Institute of Urban Meteorology, Beijing Meteorological Bureau, Beijing 100089, China
Received: 08 Oct 2010 – Published in Atmos. Chem. Phys. Discuss.: 28 Oct 2010 Abstract. Atmospheric particle number size distributions (size range 0.003–10 μm)
were measured between March 2008 and August 2009 at Shangdianzi (SDZ), a
rural research station in the North China Plain. These measurements were
made in an attempt to better characterize the tropospheric background
aerosol in Northern China. The mean particle number concentrations of the
total particle, as well as the nucleation, Aitken, accumulation and coarse
mode were determined to be 1.2 ± 0.9 × 104, 3.6 ± 7.9 × 103,
4.4 ± 3.4 × 103, 3.5 ± 2.8 × 103 and 2 ± 3 cm−3, respectively. A general finding was that
the particle number concentration was higher during spring compared to the
other seasons. The air mass origin had an important effect on the particle
number concentration and new particle formation events. Air masses from
northwest (i.e. inner Asia) favored the new particle formation events, while
air masses from southeast showed the highest particle mass concentration.
Significant diurnal variations in particle number were observed, which could
be linked to new particle formation events, i.e. gas-to-particle conversion.
During particle formation events, the number concentration of the nucleation
mode rose up to maximum value of 104 cm−3. New particle formation
events were observed on 36% of the effective measurement days. The
formation rate ranged from 0.7 to 72.7 cm−3 s−1, with a mean value
of 8.0 cm−3 s−1. The value of the nucleation mode growth rate was
in the range of 0.3–14.5 nm h−1, with a mean value of 4.3 nm h−1.
It was an essential observation that on many occasions the nucleation mode
was able to grow into the size of cloud condensation nuclei (CCN) within a
matter of several hours. Furthermore, the new particle formation was
regularly followed by a measurable increase in particle mass concentration
and extinction coefficient, indicative of a high abundance of condensable
vapors in the atmosphere under study.
Revised: 31 Jan 2011 – Accepted: 01 Feb 2011 – Published: 18 Feb 2011
Citation: Shen, X. J., Sun, J. Y., Zhang, Y. M., Wehner, B., Nowak, A., Tuch, T., Zhang, X. C., Wang, T. T., Zhou, H. G., Zhang, X. L., Dong, F., Birmili, W., and Wiedensohler, A.: First long-term study of particle number size distributions and new particle formation events of regional aerosol in the North China Plain, Atmos. Chem. Phys., 11, 1565-1580, doi:10.5194/acp-11-1565-2011, 2011.