Impacts of Meteorology and Emissions on O3 Pollution during 2013–2018 and Corresponding Control Strategy for a Typical Industrial City of China

Abstract

The air quality of Handan, a typical industrial city in China, has been significantly improved through atmospheric pollution control, except for ozone (O₃) pollution. We found that, in summer, emissions of anthropogenic volatile organic compounds (VOCs) and NO_x decreased yearly in Handan, but the O₃ concentration significantly declined yearly during 2013–2015, whereas it experienced worsening O₃ pollution after 2015. Therefore, we used the Weather Research and Forecasting Community Multiscale Air Quality (WRF–CMAQ) modeling system to simulate the influence of the meteorological conditions and emission changes in Handan during the typical period (June) of O₃ pollution in 2013–2018. For benchmarked June 2013, the results showed that the reduction of the O₃ concentration in June of 2014–2016 was mainly caused by emission reduction, while in June of 2017–2018, the combined effect of changes in emissions and meteorological conditions led to aggravated O₃ pollution. Sensitivity analysis indicated that combined VOCs and NO_x emission controls would effectively reduce incremental O₃ formation when the abatement ratio of VOCs/NO_x should be no less than 0.84, and we found that VOCs reduction would continusouly bring about O₃ decreases under various NO_x reductions, but its positive sensitivity to O₃ would become smaller with NO_x reduction. However, the positive influence of NO_x reduction on O₃ would happen until NO_x reduction exceeding 45–60%. The findings will be helpful in formulating emission control strategies for coping with O₃ pollution in an industrial city.