The PM2.5 drops were decomposed into the impacts of routine emission reductions, meteorology and COVID-19 quarantines. Meteorological conditions caused a 30 % and 14 % increase of PM2.5 in North China and Hubei Province. PM2.5 dropped by 30–60 μg/m3 in North China and 0–30 μg/m3 in the south due to the COVID-19 quarantines.
The PM2.5 drops were decomposed into the impacts of routine emission reductions, meteorology and...
1Key Laboratory of Meteorological Disaster, Ministry of Education/Joint International Research Laboratory of Climate and Environment Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing, 210044, China
2Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519080, China
3Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
1Key Laboratory of Meteorological Disaster, Ministry of Education/Joint International Research Laboratory of Climate and Environment Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing, 210044, China
2Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519080, China
3Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
Received: 10 Jul 2020 – Accepted for review: 24 Aug 2020 – Discussion started: 31 Aug 2020
Abstract. The top-level emergency response to the COVID-19 pandemic involved an exhaustive quarantine in China. The impacts of COVID-19 quarantine on the decline in fine particulate matter (PM2.5) were quantitatively assessed based on numerical simulations and observations in February. The stable meteorological conditions in February 2020 caused considerable PM2.5 anomalies that were eliminated in advance. The contributions of routine emission reductions were also quantitatively extrapolated. The top-level emergency response substantially alleviated the level of haze pollution in the east of China. Although climate variability elevated the PM2.5 by 29 % (relative to 2020 observations), 59 % decline related to COVID-19 pandemic and 20 % decline from the expected pollution regulation dramatically exceeded the former in North China. The COVID-19 quarantine measures decreased the PM2.5 in Yangtze River Delta by 72 %. In Hubei Province where most pneumonia cases were confirmed, the impact of total emission reduction (72 %) evidently exceeded the rising percentage of PM2.5 driven by meteorology (13 %).
The PM2.5 drops were decomposed into the impacts of routine emission reductions, meteorology and COVID-19 quarantines. Meteorological conditions caused a 30 % and 14 % increase of PM2.5 in North China and Hubei Province. PM2.5 dropped by 30–60 μg/m3 in North China and 0–30 μg/m3 in the south due to the COVID-19 quarantines.
The PM2.5 drops were decomposed into the impacts of routine emission reductions, meteorology and...