Spatial and Temporal Changes of Aerosol Optical Depth in Last Two Decades over Bangladesh

Spatial and Temporal Changes of Aerosol Optical Depth in Last Two Decades over Bangladesh | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Spatial and Temporal Changes of Aerosol Optical Depth in Last Two Decades over Bangladesh Md. Monirul Islam This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7809088/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 17 You are reading this latest preprint version Abstract Satellite-derived Aerosol Optical Depth (AOD) plays a crucial role in assessing both climate change and air quality impacts on human health at local to global scales. This study investigates the spatial and temporal variations of aerosol loading over Bangladesh during the last two decades (2002–2021) using AOD products retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard the Terra satellite. Aerosol distribution patterns were analyzed using three MODIS retrieval algorithms: Dark Target (DT), Deep Blue (DB) and their combined dataset (DTB). The results show consistently high AOD values (> 0.60) in western Bangladesh, with elevated aerosol regions gradually expanding towards the northeastern, eastern, and southeastern parts of the country. Seasonal analyses indicate the highest aerosol concentrations during the pre-monsoon season and the lowest during the post-monsoon period. Average AOD values for DT, DB and DTB products during pre-monsoon were 0.71, 0.61 and 0.71, respectively, whereas post-monsoon averages were 0.43, 0.40, and 0.44. Monthly trends show peak AOD in July and a minimum in October. To assess the accuracy of MODIS retrievals, AOD values were validated using ground-based observations from the Aerosol Robotic Network (AERONET) at two stations located at Dhaka University and Bhola sites in Bangladesh. The validation showed that the DB algorithm performed better in urban conditions, whereas DTB provided more reliable estimates in coastal regions. The findings from this study offer valuable insights into the long-term aerosol distribution patterns over Bangladesh and their implications for regional climate and environmental research. MODIS AOD DT DB DTB Bangladesh Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 02 Mar, 2026 Reviews received at journal 02 Mar, 2026 Reviews received at journal 23 Feb, 2026 Reviewers agreed at journal 21 Feb, 2026 Reviewers agreed at journal 21 Feb, 2026 Reviewers agreed at journal 21 Feb, 2026 Reviewers agreed at journal 20 Feb, 2026 Reviewers agreed at journal 20 Feb, 2026 Reviewers agreed at journal 20 Feb, 2026 Reviews received at journal 19 Feb, 2026 Reviewers agreed at journal 19 Feb, 2026 Reviewers agreed at journal 19 Feb, 2026 Reviewers agreed at journal 19 Feb, 2026 Reviewers invited by journal 19 Feb, 2026 Editor assigned by journal 17 Oct, 2025 Submission checks completed at journal 16 Oct, 2025 First submitted to journal 08 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7809088","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":595477641,"identity":"aaa2c0cc-dbda-4669-84ab-65c42e3afe85","order_by":0,"name":"Md. 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This study investigates the spatial and temporal variations of aerosol loading over Bangladesh during the last two decades (2002\u0026ndash;2021) using AOD products retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard the Terra satellite. Aerosol distribution patterns were analyzed using three MODIS retrieval algorithms: Dark Target (DT), Deep Blue (DB) and their combined dataset (DTB). The results show consistently high AOD values (\u0026gt;\u0026thinsp;0.60) in western Bangladesh, with elevated aerosol regions gradually expanding towards the northeastern, eastern, and southeastern parts of the country. Seasonal analyses indicate the highest aerosol concentrations during the pre-monsoon season and the lowest during the post-monsoon period. Average AOD values for DT, DB and DTB products during pre-monsoon were 0.71, 0.61 and 0.71, respectively, whereas post-monsoon averages were 0.43, 0.40, and 0.44. 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The findings from this study offer valuable insights into the long-term aerosol distribution patterns over Bangladesh and their implications for regional climate and environmental research.\u003c/p\u003e","manuscriptTitle":"Spatial and Temporal Changes of Aerosol Optical Depth in Last Two Decades over Bangladesh","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-24 15:34:29","doi":"10.21203/rs.3.rs-7809088/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-02T09:41:03+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-02T08:38:38+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-23T08:29:11+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"47785709893582568171168675248685801272","date":"2026-02-21T12:36:11+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"97214207000320006367765611874818026519","date":"2026-02-21T12:36:09+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"219082477823952941014143929220691813469","date":"2026-02-21T12:20:11+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"29195619488727445980367744899573338742","date":"2026-02-20T12:57:20+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"160980506138828992388955546201191438447","date":"2026-02-20T09:51:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"331002194726911704361485694929831390514","date":"2026-02-20T08:44:53+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-19T18:34:27+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"234517230791295296440000477176131876036","date":"2026-02-19T15:39:11+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"241742838474635861137677398957500898049","date":"2026-02-19T15:06:31+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"288557251828153806665075695882248519620","date":"2026-02-19T13:14:21+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-19T12:14:30+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-17T13:01:19+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-17T01:21:46+00:00","index":"","fulltext":""},{"type":"submitted","content":"Remote Sensing in Earth Systems Sciences","date":"2025-10-08T14:36:32+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"remote-sensing-in-earth-systems-sciences","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"rses","sideBox":"Learn more about [Remote Sensing in Earth Systems Sciences](https://link.springer.com/journal/41976)","snPcode":"41976","submissionUrl":"https://submission.nature.com/new-submission/41976/3","title":"Remote Sensing in Earth Systems Sciences","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"18590fde-b8eb-46bf-91a4-2dadbf7d83b2","owner":[],"postedDate":"February 24th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-15T16:08:12+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-24 15:34:29","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7809088","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7809088","identity":"rs-7809088","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}