Impact of COVID-19 Control Measures on Trace Gases (NO2, HCHO and SO2) and Aerosols over India during Pre-monsoon of 2020

Abstract To prevent the transmission of COVID-19, India implemented country-wide restrictions on socio-economic activities. Using satellite observations for the pre-monsoon (March–April–May) season, we explore the effect of the extended lockdown, on nitrogen dioxide (NO2), formaldehyde (HCHO), sulfu...

Full description

Saved in:
Bibliographic Details
Main Authors: Mriganka Sekhar Biswas, D. C. Ayantika
Format: Article
Language:English
Published: Springer 2020-10-01
Series:Aerosol and Air Quality Research
Subjects:
Online Access:https://doi.org/10.4209/aaqr.2020.06.0306
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1823862921243918336
author Mriganka Sekhar Biswas
D. C. Ayantika
author_facet Mriganka Sekhar Biswas
D. C. Ayantika
author_sort Mriganka Sekhar Biswas
collection DOAJ
description Abstract To prevent the transmission of COVID-19, India implemented country-wide restrictions on socio-economic activities. Using satellite observations for the pre-monsoon (March–April–May) season, we explore the effect of the extended lockdown, on nitrogen dioxide (NO2), formaldehyde (HCHO), sulfur dioxide (SO2) and aerosol optical depth (AOD) over India. In this present study we evaluate and quantify the changes in pollutants across six different geographical zones along with the six most populous cities in the country. During April–May the lockdown have resulted in a net decrease in NO2 column density over India in 2020 compared to 2017–2019 average for the same months. Maximum average seasonal reduction of both NO2 (−5.6%) and HCHO (−1.3%) occurred over southern India (SI). Compared to March and April, anomalous HCHO for all the regions decreased in May. Anomalous surface cooling induced lower volatile organic carbons (VOCs) emission and slower VOC oxidation due to absence of high nitric oxide led to decrease in HCHO. A reduction in NO2 was also seen over the top six populous Indian cities, with Mumbai recording the highest decrease (−33.7%). But only Chennai showed a substantial decrease (−6.8%) in HCHO. A significant seasonal reduction in SO2 was noted over western India (WI) and SI. Additionally, widespread decline covering all the zones was found in the pre-monsoon AOD. In April, the decrease occurred primarily over the Indo-Gangetic-Plains (IGP) and eastern India, while in May a marked homogeneous reduction was noted over entire India. Aerosol induced attenuation of incident solar radiation leads to concurrent changes in MERRA2 insolation during pre-monsoon of 2020. Furthermore, reduced anthropogenic aerosols resulted in reduction of availed cloud condensation nuclei (CCN) leading to larger cloud droplet size and hence increased precipitation during pre-monsoon, 2020.
format Article
id doaj-art-b4abb42d6bce4c19a649b95ed37ed38b
institution Kabale University
issn 1680-8584
2071-1409
language English
publishDate 2020-10-01
publisher Springer
record_format Article
series Aerosol and Air Quality Research
spelling doaj-art-b4abb42d6bce4c19a649b95ed37ed38b2025-02-09T12:20:50ZengSpringerAerosol and Air Quality Research1680-85842071-14092020-10-0121112010.4209/aaqr.2020.06.0306Impact of COVID-19 Control Measures on Trace Gases (NO2, HCHO and SO2) and Aerosols over India during Pre-monsoon of 2020Mriganka Sekhar Biswas0D. C. Ayantika1Centre for Climate Change Research, Indian Institute of Tropical Meteorology, Ministry of Earth SciencesCentre for Climate Change Research, Indian Institute of Tropical Meteorology, Ministry of Earth SciencesAbstract To prevent the transmission of COVID-19, India implemented country-wide restrictions on socio-economic activities. Using satellite observations for the pre-monsoon (March–April–May) season, we explore the effect of the extended lockdown, on nitrogen dioxide (NO2), formaldehyde (HCHO), sulfur dioxide (SO2) and aerosol optical depth (AOD) over India. In this present study we evaluate and quantify the changes in pollutants across six different geographical zones along with the six most populous cities in the country. During April–May the lockdown have resulted in a net decrease in NO2 column density over India in 2020 compared to 2017–2019 average for the same months. Maximum average seasonal reduction of both NO2 (−5.6%) and HCHO (−1.3%) occurred over southern India (SI). Compared to March and April, anomalous HCHO for all the regions decreased in May. Anomalous surface cooling induced lower volatile organic carbons (VOCs) emission and slower VOC oxidation due to absence of high nitric oxide led to decrease in HCHO. A reduction in NO2 was also seen over the top six populous Indian cities, with Mumbai recording the highest decrease (−33.7%). But only Chennai showed a substantial decrease (−6.8%) in HCHO. A significant seasonal reduction in SO2 was noted over western India (WI) and SI. Additionally, widespread decline covering all the zones was found in the pre-monsoon AOD. In April, the decrease occurred primarily over the Indo-Gangetic-Plains (IGP) and eastern India, while in May a marked homogeneous reduction was noted over entire India. Aerosol induced attenuation of incident solar radiation leads to concurrent changes in MERRA2 insolation during pre-monsoon of 2020. Furthermore, reduced anthropogenic aerosols resulted in reduction of availed cloud condensation nuclei (CCN) leading to larger cloud droplet size and hence increased precipitation during pre-monsoon, 2020.https://doi.org/10.4209/aaqr.2020.06.0306COVID-19Nitrogen dioxide (NO2)Formaldehyde (HCHO)Aerosol Optical Depth (AOD)Surface solar radiation
spellingShingle Mriganka Sekhar Biswas
D. C. Ayantika
Impact of COVID-19 Control Measures on Trace Gases (NO2, HCHO and SO2) and Aerosols over India during Pre-monsoon of 2020
Aerosol and Air Quality Research
COVID-19
Nitrogen dioxide (NO2)
Formaldehyde (HCHO)
Aerosol Optical Depth (AOD)
Surface solar radiation
title Impact of COVID-19 Control Measures on Trace Gases (NO2, HCHO and SO2) and Aerosols over India during Pre-monsoon of 2020
title_full Impact of COVID-19 Control Measures on Trace Gases (NO2, HCHO and SO2) and Aerosols over India during Pre-monsoon of 2020
title_fullStr Impact of COVID-19 Control Measures on Trace Gases (NO2, HCHO and SO2) and Aerosols over India during Pre-monsoon of 2020
title_full_unstemmed Impact of COVID-19 Control Measures on Trace Gases (NO2, HCHO and SO2) and Aerosols over India during Pre-monsoon of 2020
title_short Impact of COVID-19 Control Measures on Trace Gases (NO2, HCHO and SO2) and Aerosols over India during Pre-monsoon of 2020
title_sort impact of covid 19 control measures on trace gases no2 hcho and so2 and aerosols over india during pre monsoon of 2020
topic COVID-19
Nitrogen dioxide (NO2)
Formaldehyde (HCHO)
Aerosol Optical Depth (AOD)
Surface solar radiation
url https://doi.org/10.4209/aaqr.2020.06.0306
work_keys_str_mv AT mrigankasekharbiswas impactofcovid19controlmeasuresontracegasesno2hchoandso2andaerosolsoverindiaduringpremonsoonof2020
AT dcayantika impactofcovid19controlmeasuresontracegasesno2hchoandso2andaerosolsoverindiaduringpremonsoonof2020