Tags

Type your tag names separated by a space and hit enter

Improvement in air quality and its impact on land surface temperature in major urban areas across India during the first lockdown of the pandemic.
Environ Res. 2021 08; 199:111280.ER

Abstract

The SARS CoV-2 (COVID-19) pandemic and the enforced lockdown have reduced the use of surface and air transportation. This study investigates the impact of the lockdown restrictions in India on atmospheric composition, using Sentinel-5Ps retrievals of tropospheric NO2 concentration and ground-station measurements of NO2 and PM2.5 between March-May in 2019 and 2020. Detailed analysis of the changes to atmospheric composition are carried out over six major urban areas (i.e. Delhi, Mumbai, Kolkata, Chennai, Bangalore, and Hyderabad) by comparing Moderate Resolution Imaging Spectroradiometer (MODIS) Aerosol Optical Depth (AOD) and land surface temperature (LST) measurements in the lockdown year 2020 and pre-lockdown (2015-2019). Satellite-based data showed that NO2 concentration reduced by 18% (Kolkata), 29% (Hyderabad), 32-34% (Chennai, Mumbai, and Bangalore), and 43% (Delhi). Surface-based concentrations of NO2, PM2.5, and AOD also substantially dropped by 32-74%, 10-42%, and 8-34%, respectively over these major cities during the lockdown period and co-located with the intensity of anthropogenic activity. Only a smaller fraction of the reduction of pollutants was associated with meteorological variability. A substantial negative anomaly was found for LST both in the day (-0.16 °C to -1 °C) and night (-0.63 °C to -2.1 °C) across select all cities, which was also consistent with air temperature measurements. The decreases in LST could be associated with a reduction in pollutants, greenhouse gases and water vapor content. Improvement in air quality with lower urban temperatures due to lockdown may be a temporary effect, but it provides a crucial connection among human activities, air pollution, aerosols, radiative flux, and temperature. The lockdown for a shorter-period showed a significant improvement in environmental quality and provides a strong evidence base for larger scale policy implementation to improve air quality.

Authors+Show Affiliations

Department of Geoinformatics, School of Natural Resource Management, Central University of Jharkhand, Ranchi, 835222, India. Electronic address: bikashrp@gmail.com.Department of Geoinformatics, School of Natural Resource Management, Central University of Jharkhand, Ranchi, 835222, India.Geography and Environmental Science, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom.Department of Geoinformatics, School of Natural Resource Management, Central University of Jharkhand, Ranchi, 835222, India.Department of Geoinformatics, School of Natural Resource Management, Central University of Jharkhand, Ranchi, 835222, India.Department of Environmental Sciences, School of Natural Resource Management, Central University of Jharkhand, Ranchi, 835222, India.Geography and Environmental Science, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

34029544

Citation

Parida, Bikash Ranjan, et al. "Improvement in Air Quality and Its Impact On Land Surface Temperature in Major Urban Areas Across India During the First Lockdown of the Pandemic." Environmental Research, vol. 199, 2021, p. 111280.
Parida BR, Bar S, Roberts G, et al. Improvement in air quality and its impact on land surface temperature in major urban areas across India during the first lockdown of the pandemic. Environ Res. 2021;199:111280.
Parida, B. R., Bar, S., Roberts, G., Mandal, S. P., Pandey, A. C., Kumar, M., & Dash, J. (2021). Improvement in air quality and its impact on land surface temperature in major urban areas across India during the first lockdown of the pandemic. Environmental Research, 199, 111280. https://doi.org/10.1016/j.envres.2021.111280
Parida BR, et al. Improvement in Air Quality and Its Impact On Land Surface Temperature in Major Urban Areas Across India During the First Lockdown of the Pandemic. Environ Res. 2021;199:111280. PubMed PMID: 34029544.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Improvement in air quality and its impact on land surface temperature in major urban areas across India during the first lockdown of the pandemic. AU - Parida,Bikash Ranjan, AU - Bar,Somnath, AU - Roberts,Gareth, AU - Mandal,Shyama Prasad, AU - Pandey,Arvind Chandra, AU - Kumar,Manoj, AU - Dash,Jadunandan, Y1 - 2021/05/21/ PY - 2020/09/24/received PY - 2021/02/12/revised PY - 2021/04/30/accepted PY - 2021/5/25/pubmed PY - 2021/6/16/medline PY - 2021/5/24/entrez KW - AOD KW - Atmospheric pollutants KW - LST KW - Net radiative flux KW - Water vapor SP - 111280 EP - 111280 JF - Environmental research JO - Environ Res VL - 199 N2 - The SARS CoV-2 (COVID-19) pandemic and the enforced lockdown have reduced the use of surface and air transportation. This study investigates the impact of the lockdown restrictions in India on atmospheric composition, using Sentinel-5Ps retrievals of tropospheric NO2 concentration and ground-station measurements of NO2 and PM2.5 between March-May in 2019 and 2020. Detailed analysis of the changes to atmospheric composition are carried out over six major urban areas (i.e. Delhi, Mumbai, Kolkata, Chennai, Bangalore, and Hyderabad) by comparing Moderate Resolution Imaging Spectroradiometer (MODIS) Aerosol Optical Depth (AOD) and land surface temperature (LST) measurements in the lockdown year 2020 and pre-lockdown (2015-2019). Satellite-based data showed that NO2 concentration reduced by 18% (Kolkata), 29% (Hyderabad), 32-34% (Chennai, Mumbai, and Bangalore), and 43% (Delhi). Surface-based concentrations of NO2, PM2.5, and AOD also substantially dropped by 32-74%, 10-42%, and 8-34%, respectively over these major cities during the lockdown period and co-located with the intensity of anthropogenic activity. Only a smaller fraction of the reduction of pollutants was associated with meteorological variability. A substantial negative anomaly was found for LST both in the day (-0.16 °C to -1 °C) and night (-0.63 °C to -2.1 °C) across select all cities, which was also consistent with air temperature measurements. The decreases in LST could be associated with a reduction in pollutants, greenhouse gases and water vapor content. Improvement in air quality with lower urban temperatures due to lockdown may be a temporary effect, but it provides a crucial connection among human activities, air pollution, aerosols, radiative flux, and temperature. The lockdown for a shorter-period showed a significant improvement in environmental quality and provides a strong evidence base for larger scale policy implementation to improve air quality. SN - 1096-0953 UR - https://www.unboundmedicine.com/medline/citation/34029544/Improvement_in_air_quality_and_its_impact_on_land_surface_temperature_in_major_urban_areas_across_India_during_the_first_lockdown_of_the_pandemic_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0013-9351(21)00574-0 DB - PRIME DP - Unbound Medicine ER -