Index Geophysics

Significant increase of summertime ozone at Mount Tai in Central Eastern
China

Tropospheric ozone (O₃) is a trace gas playing important roles in atmospheric chemistry, air quality and climate change. In contrast to North America and Europe, long-term measurements of surface O₃ are very limited in China. We compile available O₃ observations at Mt. Tai – the highest mountain over the North China Plain – during 2003–2015 and analyze the decadal change of O₃ and its sources. A linear regression analysis shows that summertime O₃ measured at Mt. Tai has increased significantly by 1.7 ppbv yr⁻¹ for June and 2.1 ppbv yr⁻¹ for the July–August average. The observed increase is supported by a global chemistry-climate model hindcast (GFDL-AM3) with O₃ precursor emissions varying from year to year over 1980–2014. Analysis of satellite data indicates that the O₃ increase was mainly due to the increased emissions of O₃ precursors, in particular volatile organic compounds (VOCs). An important finding is that the emissions of nitrogen oxides (NO_<i>x</i>) have diminished since 2011, but the increase of VOCs appears to have enhanced the ozone production efficiency and contributed to the observed O₃ increase in central eastern China. We present evidence that controlling NO_<i>x</i> alone, in the absence of VOC controls, is not sufficient to reduce regional O₃ levels in North China in a short period.

Sun, Lei

Xue, Likun

Wang, Tao

Gao, Jian

Ding, Aijun

Cooper, Owen R.

Lin, Meiyun

Xu, Pengju

Wang, Zhe

Wang, Xinfeng

Wen, Liang

Zhu, Yanhong

Chen, Tianshu

Yang, Lingxiao

Wang, Yan

Chen, Jianmin

Wang, Wenxing

2018-09-19

Text

application/pdf

10.5194/acp-16-10637-2016

https://acp.copernicus.org/articles/16/10637/2016/

eISSN: 1680-7324

eng