Change of CO Concentration Due to the COVID-19 Lockdown in China Observed by Surface and Satellite Observations

Abstract

The nationwide lockdown due to the COVID-19 pandemic in 2020 reduced industrial and human activities in China. In this study, we investigate atmospheric carbon monoxide (CO) concentration changes during the lockdown from observations at the surface and from two satellites (TROPOspheric Monitoring Instrument (TROPOMI) and Infrared Atmospheric Sounding Interferometer (IASI)). It is found that the average CO surface concentration in 2020 was close to that in 2019 before the lockdown, and became 18.7% lower as compared to 2019 during the lockdown. The spatial variation of the change in the CO surface concentration is high, with an 8–27% reduction observed for Beijing, Shanghai, Chengdu, Zhengzhou, and Guangzhou, and almost no change in Wuhan. The TROPOMI and IASI satellite observations show that the CO columns decreased by 2–13% during the lockdown in most regions in China. However in South China, there was an 8.8% increase in the CO columns observed by TROPOMI and a 36.7% increase observed by IASI, which is contrary to the 23% decrease in the surface CO concentration. The enhancement of the CO column in South China is strongly affected by the fire emissions transported from Southeast Asia. This study provides an insight into the impact of COVID-19 on CO concentrations both at the surface and in the columns in China, and it can be extended to evaluate other areas using the same approach.

Declining carbon emission/concentration during COVID-19: A critical review on temporary relief

“…Zhou et al 25 studied the change in carbon monoxide (CO) concentration in 1375 sites of China during lockdown employing surface-based and satellite-based observations. They found that the average CO surface concentration was reduced by 18.7% with a spatial variation of 8-27%.…”

An Analysis of the Work Resumption in China under the COVID-19 Epidemic Based on Night Time Lights Data

“…Artificial night time skyglow as a supplement to night time light remote sensing data is affected by air quality [62,63]. Air pollution decreases due to COVID-19 city lockdown [64,65]. However, to our knowledge, the effect of air quality on artificial skyglow has not been quantified.…”

Declining Carbon Emission/Concentration during COVID-19: A critical review on temporary relief

“…In another study 23 , they have employed satellite-based data between January and April 2020 and estimated that China's CO2 emissions reduced by 11.5% in comparison to the same period in 2019. The study of Tohjima et al 24 Zhou et al 25 studied the change in carbon monoxide (CO) concentration in 1375 sites of China during lockdown employing surface-based and satellite-based observations. They found that the average CO surface concentration was reduced by 18.7% with a spatial variation of 8-27%.…”