{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,8]],"date-time":"2026-02-08T18:34:07Z","timestamp":1770575647701,"version":"3.49.0"},"reference-count":44,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2022,9,17]],"date-time":"2022-09-17T00:00:00Z","timestamp":1663372800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The study evaluates the impacts of India\u2019s COVID-19 lockdown and unlocking periods on the country\u2019s ambient air quality. India experienced three strictly enforced lockdowns followed by unlocking periods where economic and social restrictions were gradually lifted. We have examined the in situ and satellite data of NO2 emissions for several Indian cities to assess the impacts of the lockdowns in India. Additionally, we analyzed NO2 data acquired from the Sentinel-5P TROPOMI sensor over a few districts of the Punjab state, as well as the National Capital Region. The comparisons between the in situ and satellite NO2 emissions were performed for the years 2019, 2020 and up to July 2021. Further analysis was conducted on the satellite data to map the NO2 emissions over India during March to July for the years of 2019, 2020 and 2021. Based on the in situ and satellite observations, we observed that the NO2 emissions significantly decreased by 45\u201355% in the first wave and 30% in the second wave, especially over the Northern Indian cities during the lockdown periods. The improved air quality over India is indicative of reduced pollution in the atmosphere due to the lockdown process, which slowed down the industrial and commercial activities, including the migration of humans from one place to another. Overall, the present study contributes to the understanding of the trends of the ambient air quality over large geographical areas using the Sentinel-5P satellite data and provides valuable information for regulatory bodies to design a better decision support system to improve air quality.<\/jats:p>","DOI":"10.3390\/rs14184650","type":"journal-article","created":{"date-parts":[[2022,9,19]],"date-time":"2022-09-19T04:49:22Z","timestamp":1663562962000},"page":"4650","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Geospatial Technology-Based Analysis of Air Quality in India during the COVID-19 Pandemic"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9593-4508","authenticated-orcid":false,"given":"Ajay Kumar","family":"Taloor","sequence":"first","affiliation":[{"name":"Department of Remote Sensing and GIS, University of Jammu, Jammu 180006, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4452-9729","authenticated-orcid":false,"given":"Anil Kumar","family":"Singh","sequence":"additional","affiliation":[{"name":"Department of Earth & Planetary Sciences, University of Allahabad, Prayagraj 211002, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7099-7297","authenticated-orcid":false,"given":"Pankaj","family":"Kumar","sequence":"additional","affiliation":[{"name":"Institute for Global Environmental Strategies, Hayama 240-0115, Kanagawa, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1832-5754","authenticated-orcid":false,"given":"Amit","family":"Kumar","sequence":"additional","affiliation":[{"name":"India Meteorological Department, Ministry of Earth Sciences, New Delhi 110003, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0529-5437","authenticated-orcid":false,"given":"Jayant Nath","family":"Tripathi","sequence":"additional","affiliation":[{"name":"Department of Earth & Planetary Sciences, University of Allahabad, Prayagraj 211002, India"},{"name":"Centre for Disaster Management, University of Allahabad, Prayagraj 211002, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7479-2803","authenticated-orcid":false,"given":"Maya","family":"Kumari","sequence":"additional","affiliation":[{"name":"Amity School of Natural Resources and Sustainable Development, Amity University, Sector 125, Noida 201303, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bahadur Singh","family":"Kotlia","sequence":"additional","affiliation":[{"name":"Centre of Advanced Study in Geology, Kumaun University, Nainital 263001, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Girish Ch","family":"Kothyari","sequence":"additional","affiliation":[{"name":"Department of Petroleum Engineering and Earth Sciences, University of Petroleum and Energy Studies, Dehradun 248007, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8833-132X","authenticated-orcid":false,"given":"Surya Prakash","family":"Tiwari","sequence":"additional","affiliation":[{"name":"Centre for Environment and Water, The Research Institute, King Fahd University of Petroleum & Minerals (K.F.U.P.M.), Dhahran 31261, Saudi Arabia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1911-3585","authenticated-orcid":false,"given":"Brian Alan","family":"Johnson","sequence":"additional","affiliation":[{"name":"Institute for Global Environmental Strategies, Hayama 240-0115, Kanagawa, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,9,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"38","DOI":"10.1038\/s41612-020-00142-x","article-title":"Exploring dependence of COVID-19 on environmental factors and spread prediction in India","volume":"3","author":"Bherwani","year":"2020","journal-title":"NPJ Clim. 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