TY - JOUR
T1 - Distinct regimes of O3 response to covid-19 lockdown in China
AU - Liu, Shanshan
AU - Liu, Cheng
AU - Hu, Qihou
AU - Su, Wenjing
AU - Yang, Xian
AU - Lin, Jinan
AU - Zhang, Chengxin
AU - Xing, Chengzhi
AU - Ji, Xiangguang
AU - Tan, Wei
AU - Liu, Haoran
AU - Gao, Meng
N1 - Funding Information:
Funding: This research was funded by grants from the National Key Research and Development Program of China (No. 2018YFC0213104, 2017YFC0210002, 2016YFC0203302 and 2017YFC0212800), the National Natural Science Foundation of China (No. 41722501, 51778596, and 41977184), Anhui Science and Technology Major Project (No. 18030801111), the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDA23020301), the National Key Project for Causes and Control of Heavy Air Pollution (No. DQGG0102 and DQGG0205).
Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2021/2
Y1 - 2021/2
N2 - 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 < 0.001). In contrast, a decline was detected (−1.1%) in the Pearl River Delta (PRD) region. To better understand the underlying causes for these inconsistent responses across China, we adopted the least absolute shrinkage and selection operator (Lasso) and ordinary linear squares (OLS) methods in this study. Statistical analysis indicated that a sharp decline in nitrogen dioxide (NO2) 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.
AB - 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 < 0.001). In contrast, a decline was detected (−1.1%) in the Pearl River Delta (PRD) region. To better understand the underlying causes for these inconsistent responses across China, we adopted the least absolute shrinkage and selection operator (Lasso) and ordinary linear squares (OLS) methods in this study. Statistical analysis indicated that a sharp decline in nitrogen dioxide (NO2) 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.
KW - Control strategies
KW - COVID-19
KW - Lasso statistical analysis
KW - O3 response
UR - http://www.scopus.com/inward/record.url?scp=85101157888&partnerID=8YFLogxK
U2 - 10.3390/atmos12020184
DO - 10.3390/atmos12020184
M3 - Journal article
AN - SCOPUS:85101157888
SN - 2073-4433
VL - 12
JO - Atmosphere
JF - Atmosphere
IS - 2
M1 - 184
ER -