Distinct Regimes of O<sub>3</sub> Response to COVID-19 Lockdown in China
Shanshan Liu,
Cheng Liu,
Qihou Hu,
Wenjing Su,
Xian Yang,
Jinan Lin,
Chengxin Zhang,
Chengzhi Xing,
Xiangguang Ji,
Wei Tan,
Haoran Liu,
Meng Gao
Affiliations
Shanshan Liu
School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China
Cheng Liu
Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
Qihou Hu
Key Laboratory of Environmental Optics & Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
Wenjing Su
School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China
Xian Yang
Department of Computer Science, Hong Kong Baptist University, Hong Kong, China
Jinan Lin
Key Laboratory of Environmental Optics & Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
Chengxin Zhang
Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230026, China
Chengzhi Xing
Key Laboratory of Environmental Optics & Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
Xiangguang Ji
Key Laboratory of Environmental Optics & Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
Wei Tan
Key Laboratory of Environmental Optics & Technology, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
Haoran Liu
Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
Meng Gao
Department of Geography, Hong Kong Baptist University, Hong Kong, China
Restrictions on human activities remarkably reduced emissions of air pollutants in China during the COVID-19 lockdown periods. However, distinct responses of O3 concentrations were observed across China. In the Beijing–Tianjin–Hebei (BTH) and Yangtze River Delta (YRD) regions, O3 concentrations were enhanced by 90.21 and 71.79% from pre-lockdown to lockdown periods in 2020, significantly greater than the equivalent concentrations for the same periods over 2015–2019 (69.99 and 43.62%, p 2) was the major driver of enhanced O3 in the BTH region as it is a NOx-saturated region. In the YRD region, season-shift induced changes in the temperature/shortwave radiative flux, while lockdown induced declines in NO2, attributable to the rise in O3. In the PRD region, the slight drop in O3 is attributed to the decreased intensity of radiation. The distinct regimes of the O3 response to the COVID-19 lockdown in China offer important insights into different O3 control strategies across China.
