Spatial and Temporal Distribution Characteristics of Ozone Concentration and Source Analysis during the COVID-19 Lockdown Period in Shanghai
In March 2022, a new wave of COVID-19 outbreak occurred in Shanghai due to the widespread transmission of the Omicron variant. A two-month citywide lockdown was implemented from April 1st to May 31st, adopting measures such as zone-based classification and grid management. This unique social event p...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-10-01
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| Series: | Atmosphere |
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| Online Access: | https://www.mdpi.com/2073-4433/14/10/1563 |
| _version_ | 1797574739787513856 |
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| author | Shinan Shen Li He Wanqi Chen Shuang Chen Weichun Ma |
| author_facet | Shinan Shen Li He Wanqi Chen Shuang Chen Weichun Ma |
| author_sort | Shinan Shen |
| collection | DOAJ |
| description | In March 2022, a new wave of COVID-19 outbreak occurred in Shanghai due to the widespread transmission of the Omicron variant. A two-month citywide lockdown was implemented from April 1st to May 31st, adopting measures such as zone-based classification and grid management. This unique social event provided an “ideal air quality experiment” for pollution research. The rapid reduction in economic activities during the lockdown had many positive impacts on the environment, leading to overall improvements in air quality. Particularly, the concentration of NOx, one of the precursors to O<sub>3</sub>, significantly decreased. However, O<sub>3</sub>, as a typical secondary pollutant, showed a noticeable increase. This study uses the WRF-CAMx-OSAT air quality model method to analyze the source of O<sub>3</sub> pollution in Shanghai from April to May 2022. The impact of O<sub>3</sub> precursor control, sector sources, and regional contributions on the formation of O<sub>3</sub> pollution in Shanghai is analyzed in depth. During the pandemic lockdown period, it was found that, in Shanghai, the overall O<sub>3</sub> levels were controlled by VOCs (Volatile Organic Compounds), and controlling VOCs proved to be an effective measure in reducing O<sub>3</sub> concentrations in Shanghai. Compared with the same period in 2021, the proportion of road traffic sources contributing to ozone concentration has significantly decreased from 70.61% to 64.3%, but they are still the largest contributor. The contribution of industrial emissions to the ozone concentration has significantly risen from 20.71% to 26.36%, making them still the second largest contributor. Industrial and traffic sources are emission sources that require particular attention. The contribution ratio of local sources to external transport is about 7:3, which is higher than the ratio of local sources to external transport in the same period of 2021, which is about 6:4. The local ozone is the main source of ozone concentration in Shanghai, and controlling local source emissions is the key to controlling ozone concentration in the Shanghai area. When excluding the impact of long-range transport, the main areas contributing to O<sub>3</sub> formation from local sources are Baoshan District, Jiading District, Qingpu District, and Chongming District, accounting for approximately 41.12% of the total absolute contribution. Different source regions exhibit significant spatial variations in their contributions to the ozone concentration. Through these studies, we aim to provide scientific support and control suggestions for the precise prevention and control of O<sub>3</sub> pollution in Shanghai. |
| first_indexed | 2024-03-10T21:27:37Z |
| format | Article |
| id | doaj.art-97c10195c795439daecd1bb439ad5bfc |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-10T21:27:37Z |
| publishDate | 2023-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-97c10195c795439daecd1bb439ad5bfc2023-11-19T15:36:48ZengMDPI AGAtmosphere2073-44332023-10-011410156310.3390/atmos14101563Spatial and Temporal Distribution Characteristics of Ozone Concentration and Source Analysis during the COVID-19 Lockdown Period in ShanghaiShinan Shen0Li He1Wanqi Chen2Shuang Chen3Weichun Ma4Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, ChinaEnvironment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, ChinaDepartment of Environmental Science and Engineering, Fudan University, Shanghai 200433, ChinaDepartment of Environmental Science and Engineering, Fudan University, Shanghai 200433, ChinaDepartment of Environmental Science and Engineering, Fudan University, Shanghai 200433, ChinaIn March 2022, a new wave of COVID-19 outbreak occurred in Shanghai due to the widespread transmission of the Omicron variant. A two-month citywide lockdown was implemented from April 1st to May 31st, adopting measures such as zone-based classification and grid management. This unique social event provided an “ideal air quality experiment” for pollution research. The rapid reduction in economic activities during the lockdown had many positive impacts on the environment, leading to overall improvements in air quality. Particularly, the concentration of NOx, one of the precursors to O<sub>3</sub>, significantly decreased. However, O<sub>3</sub>, as a typical secondary pollutant, showed a noticeable increase. This study uses the WRF-CAMx-OSAT air quality model method to analyze the source of O<sub>3</sub> pollution in Shanghai from April to May 2022. The impact of O<sub>3</sub> precursor control, sector sources, and regional contributions on the formation of O<sub>3</sub> pollution in Shanghai is analyzed in depth. During the pandemic lockdown period, it was found that, in Shanghai, the overall O<sub>3</sub> levels were controlled by VOCs (Volatile Organic Compounds), and controlling VOCs proved to be an effective measure in reducing O<sub>3</sub> concentrations in Shanghai. Compared with the same period in 2021, the proportion of road traffic sources contributing to ozone concentration has significantly decreased from 70.61% to 64.3%, but they are still the largest contributor. The contribution of industrial emissions to the ozone concentration has significantly risen from 20.71% to 26.36%, making them still the second largest contributor. Industrial and traffic sources are emission sources that require particular attention. The contribution ratio of local sources to external transport is about 7:3, which is higher than the ratio of local sources to external transport in the same period of 2021, which is about 6:4. The local ozone is the main source of ozone concentration in Shanghai, and controlling local source emissions is the key to controlling ozone concentration in the Shanghai area. When excluding the impact of long-range transport, the main areas contributing to O<sub>3</sub> formation from local sources are Baoshan District, Jiading District, Qingpu District, and Chongming District, accounting for approximately 41.12% of the total absolute contribution. Different source regions exhibit significant spatial variations in their contributions to the ozone concentration. Through these studies, we aim to provide scientific support and control suggestions for the precise prevention and control of O<sub>3</sub> pollution in Shanghai.https://www.mdpi.com/2073-4433/14/10/1563COVID-19CAMx-OSATsource analysisozoneShanghai |
| spellingShingle | Shinan Shen Li He Wanqi Chen Shuang Chen Weichun Ma Spatial and Temporal Distribution Characteristics of Ozone Concentration and Source Analysis during the COVID-19 Lockdown Period in Shanghai Atmosphere COVID-19 CAMx-OSAT source analysis ozone Shanghai |
| title | Spatial and Temporal Distribution Characteristics of Ozone Concentration and Source Analysis during the COVID-19 Lockdown Period in Shanghai |
| title_full | Spatial and Temporal Distribution Characteristics of Ozone Concentration and Source Analysis during the COVID-19 Lockdown Period in Shanghai |
| title_fullStr | Spatial and Temporal Distribution Characteristics of Ozone Concentration and Source Analysis during the COVID-19 Lockdown Period in Shanghai |
| title_full_unstemmed | Spatial and Temporal Distribution Characteristics of Ozone Concentration and Source Analysis during the COVID-19 Lockdown Period in Shanghai |
| title_short | Spatial and Temporal Distribution Characteristics of Ozone Concentration and Source Analysis during the COVID-19 Lockdown Period in Shanghai |
| title_sort | spatial and temporal distribution characteristics of ozone concentration and source analysis during the covid 19 lockdown period in shanghai |
| topic | COVID-19 CAMx-OSAT source analysis ozone Shanghai |
| url | https://www.mdpi.com/2073-4433/14/10/1563 |
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