Articles | Volume 16, issue 6
Research article
24 Mar 2016
Research article |  | 24 Mar 2016

Significant increase of surface ozone at a rural site, north of eastern China

Zhiqiang Ma, Jing Xu, Weijun Quan, Ziyin Zhang, Weili Lin, and Xiaobin Xu

Abstract. Ozone pollution in eastern China has become one of the top environmental issues. Quantifying the temporal trend of surface ozone helps to assess the impacts of the anthropogenic precursor reductions and the likely effects of emission control strategies implemented. In this paper, ozone data collected at the Shangdianzi (SDZ) regional atmospheric background station from 2003 to 2015 are presented and analyzed to obtain the variation in the trend of surface ozone in the most polluted region of China, north of eastern China or the North China Plain. A modified Kolmogorov–Zurbenko (KZ) filter method was performed on the maximum daily average 8 h (MDA8) concentrations of ozone to separate the contributions of different factors from the variation of surface ozone and remove the influence of meteorological fluctuations on surface ozone. Results reveal that the short-term, seasonal and long-term components of ozone account for 36.4, 57.6 and 2.2 % of the total variance, respectively. The long-term trend indicates that the MDA8 has undergone a significant increase in the period of 2003–2015, with an average rate of 1.13 ± 0.01 ppb year−1 (R2 = 0.92). It is found that meteorological factors did not significantly influence the long-term variation of ozone and the increase may be completely attributed to changes in emissions. Furthermore, there is no significant correlation between the long-term O3 and NO2 trends. This study suggests that emission changes in VOCs might have played a more important role in the observed increase of surface ozone at SDZ.

Short summary
In this paper, we find that the daily maximum 8 h O3 in the eastern China has undergone a significant increase during 2003–2015, with a rate of 1.1 ppb per year. The increase of surface ozone was mainly induced by the emission changes and the meteorological factors just played a tiny negative influence. Our result also indicates that VOCs seem to play more important role in the ozone increase than the effect of NO titration.
Final-revised paper