- 期刊
- OpenAccess
Impact of Nationwide COVID-19 Lockdown on Indian Air Quality in Terms of Aerosols as Observed from the Space
摘要
Air pollution in India, especially in cities located in Indo-Gangetic plain (IGP), has exceeded all standards in the recent past. The development of an effective pollution control strategy requires knowledge of the pollutant sources, their spatio-temporal variability, and the efficacy of control strategies. The Indian government has implemented nationwide lockdown (LD) during March and April 2020 to contain the infectious disease COVID-19. LD also provides an opportunity to evaluate the efficacy of restricting anthropogenic activities in controlling air pollution. In the present paper, using data from space-borne sensors, a detailed analysis of the impact of LD on aerosols in the Indian atmosphere is presented. The aerosol optical depth (AOD), fine mode fraction (FMF), absorbing aerosol index (AAI), active fire/thermal anomaly and the HYSPLIT model is used to study the instantaneous state and spatio-temporal transportation of aerosols. On average, an overall decrease in AOD with 60% of the Indian landmass showing an average decrease of 0.16 is observed. A significant decrease in FMF indorses decreased AOD solely due to restricted anthropogenic activities, especially in IGP, which confirms the positive impact of LD on air quality. However, central, northeast and partially western India show some contrasting results which are associated with smoke from active fires. An increase of 30% in fire spots is observed during LD in these regions. The city-level analysis shows improved air quality in most of the cities located in IGP during LD. The cities located in the west, north-west and east India have shown a small decrease in AOD during LD, while in central, north-east, and few in the southern region, the increased AOD is observed in spite of LD due to increase in biomass burning.
延伸閱讀
- Puttaswamy, N., Sreekanth, V., Pillarisetti, A., Upadhya, A. R., Saidam, S., Veerappan, B., Mukhopadhyay, K., Sambandam, S., Sutaria, R., & Balakrishnan, K. (2022). Indoor and Ambient Air Pollution in Chennai, India during COVID-19 Lockdown: An Affordable Sensors Study. Aerosol and Air Quality Research, 22(1), 1-12+ap1-14-005. https://doi.org/10.4209/aaqr.210170
- Assanov, D., Kerimray, A., Batkeyev, B., & Kapsalyamova, Z. (2021). The Effects of COVID-19-related Driving Restrictions on Air Quality in an Industrial City. Aerosol and Air Quality Research, 21(9), 1-13+ap1-4-002. https://doi.org/10.4209/aaqr.200663
- Du, W., & Wang, G. (2020). Indoor Air Pollution was Nonnegligible during COVID-19 Lockdown. Aerosol and Air Quality Research, 20(9), 1851-1855. https://doi.org/10.4209/aaqr.2020.06.0281
- Biswas, M. S. (2021). Impact of COVID-19 Control Measures on Trace Gases (NO_2, HCHO and SO_2) and Aerosols over India during Pre-monsoon of 2020. Aerosol and Air Quality Research, 21(1), 1-20. https://doi.org/10.4209/aaqr.2020.06.0306
- Soni, M., Verma, S., Jethava, H., Payra, S., Lamsal, L., Gupta, P., & Singh, J. (2021). Impact of COVID-19 on the Air Quality over China and India Using Long-term (2009-2020) Multi-satellite Data. Aerosol and Air Quality Research, 21(3), 1-23+ap1-5-005. https://doi.org/10.4209/aaqr.2020.06.0295