{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,24]],"date-time":"2026-07-24T01:21:36Z","timestamp":1784856096395,"version":"3.55.0"},"reference-count":53,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2021,2,26]],"date-time":"2021-02-26T00:00:00Z","timestamp":1614297600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2016YFC1400901"],"award-info":[{"award-number":["2016YFC1400901"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"name":"the Special Project of Jiangsu Distinguished Professor","award":["1421061901001"],"award-info":[{"award-number":["1421061901001"]}]},{"DOI":"10.13039\/501100001809","name":"the National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["41976165"],"award-info":[{"award-number":["41976165"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"the Startup Foundation for Introduction Talent of NUIST","award":["2017r107"],"award-info":[{"award-number":["2017r107"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>This study investigates spatiotemporal changes in air pollution (particulate as well as gases) during the COVID-19 lockdown period over major cities of Bangladesh. The study investigated the aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard Terra and Aqua satellites, PM2.5 and PM10 from Copernicus Atmosphere Monitoring Service (CAMS), and NO2 and O3 from TROPOMI-5P, from March to June 2019\u20132020. Additionally, aerosol subtypes from the Cloud-Aerosol Lidar and Infrared Pathfinder (CALIPSO) were used to explore the aerosol types. The strict lockdown (26 March\u201330 May 2020) led to a significant reduction in AOD (up to 47%) in all major cities, while the partial lockdown (June 2020) led to increased and decreased AOD over the study area. Significant reductions in PM2.5 (37\u201377%) and PM10 (33\u201370%) were also observed throughout the country during the strict lockdown and partial lockdown. The NO2 levels decreased by 3\u201325% in March 2020 in the cities of Rajshahi, Chattogram, Sylhet, Khulna, Barisal, and Mymensingh, in April by 3\u201343% in Dhaka, Chattogram, Khulna, Barisal, Bhola, and Mymensingh, and May by 12\u201342% in Rajshahi, Sylhet, Mymensingh, and Rangpur. During the partial lockdown in June, NO2 decreased (9\u201335%) in Dhaka, Chattogram, Sylhet, Khulna, Barisal, and Rangpur compared to 2019. On the other hand, increases were observed in ozone (O3) levels, with an average increase of 3\u201312% throughout the country during the strict lockdown and only a slight reduction of 1\u20133% in O3 during the partial lockdown. In terms of aerosol types, CALIPSO observed high levels of polluted dust followed by dust, smoke, polluted continental, and clean marine-type aerosols over the country in 2019, but all types were decreased during the lockdown. The study concludes that the strict lockdown measures were able to significantly improve air quality conditions over Bangladesh due to the shutdown of industries, vehicles, and movement of people.<\/jats:p>","DOI":"10.3390\/rs13050877","type":"journal-article","created":{"date-parts":[[2021,2,26]],"date-time":"2021-02-26T06:47:20Z","timestamp":1614322040000},"page":"877","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":45,"title":["Spatiotemporal Investigations of Multi-Sensor Air Pollution Data over Bangladesh during COVID-19 Lockdown"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1167-3991","authenticated-orcid":false,"given":"Zhongfeng","family":"Qiu","sequence":"first","affiliation":[{"name":"Lab of Environmental Remote Sensing (LERS), School of Marine Sciences (SMS), Nanjing University of Information Science and Technology (NUIST), Nanjing 210044, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9002-3625","authenticated-orcid":false,"given":"Md. Arfan","family":"Ali","sequence":"additional","affiliation":[{"name":"Lab of Environmental Remote Sensing (LERS), School of Marine Sciences (SMS), Nanjing University of Information Science and Technology (NUIST), Nanjing 210044, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4015-893X","authenticated-orcid":false,"given":"Janet E.","family":"Nichol","sequence":"additional","affiliation":[{"name":"Department of Geography, School of Global Studies, University of Sussex, Brighton BN1 9RH, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1022-3999","authenticated-orcid":false,"given":"Muhammad","family":"Bilal","sequence":"additional","affiliation":[{"name":"Lab of Environmental Remote Sensing (LERS), School of Marine Sciences (SMS), Nanjing University of Information Science and Technology (NUIST), Nanjing 210044, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4770-4526","authenticated-orcid":false,"given":"Pravash","family":"Tiwari","sequence":"additional","affiliation":[{"name":"Kathmandu Institute of Applied Sciences, Bagdol, Kathmandu 44600, Nepal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Birhanu Asmerom","family":"Habtemicheal","sequence":"additional","affiliation":[{"name":"Collaborative Innovation Centre on Forecast and Evaluation of Meteorological Disasters, Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), International Joint Laboratory on Climate and Environment Change (ILCEC), Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, China"},{"name":"Department of Physics, Wollo University, Dessie P.O. Box 1145, Ethiopia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3962-4588","authenticated-orcid":false,"given":"Mansour","family":"Almazroui","sequence":"additional","affiliation":[{"name":"Center of Excellence for Climate Change Research, Department of Meteorology, King Abdulaziz University, Jeddah 21589, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sanjit Kumar","family":"Mondal","sequence":"additional","affiliation":[{"name":"Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disaster, Institute for Disaster Risk Management, School of Geographical Science, Nanjing University of Information Science and Technology, Nanjing 210044, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2238-0908","authenticated-orcid":false,"given":"Usman","family":"Mazhar","sequence":"additional","affiliation":[{"name":"School of Remote Sensing and Geomatics Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu","family":"Wang","sequence":"additional","affiliation":[{"name":"Lab of Environmental Remote Sensing (LERS), School of Marine Sciences (SMS), Nanjing University of Information Science and Technology (NUIST), Nanjing 210044, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5889-7103","authenticated-orcid":false,"given":"Sajib","family":"Sarker","sequence":"additional","affiliation":[{"name":"School of Computer and Software, Nanjing University of Information Science and Technology, Nanjing 210044, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8827-7308","authenticated-orcid":false,"given":"Farhan","family":"Mustafa","sequence":"additional","affiliation":[{"name":"Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Key Laboratory of Meteorological Disasters, Ministry of Education, Nanjing University of Information Science and Technology, Nanjing 210044, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Muhammad Ashfaqur","family":"Rahman","sequence":"additional","affiliation":[{"name":"Weather and Climate Model Earth Science Technology and Policy Services Ltd. (ESTEPS), Dhaka 1000, Bangladesh"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,2,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"809","DOI":"10.1016\/S0140-6736(20)30360-3","article-title":"Clinical Characteristics and Intrauterine Vertical Transmission Potential of COVID-19 Infection in Nine Pregnant Women: A Retrospective Review of Medical Records","volume":"395","author":"Chen","year":"2020","journal-title":"Lancet"},{"key":"ref_2","unstructured":"World Health Organization (WHO) (2020, August 15). WHO Announces COVID-19 Outbreak a Pandemic. Available online: http:\/\/www.euro.who.int\/en\/health-topics\/health-emergencies\/coronavirus-covid-%0A19\/news\/news\/2020\/3\/who-announces-covid-19-outbreak-a-pandemic."},{"key":"ref_3","unstructured":"(2020, December 16). Worldometer. 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