Nonlinear Granger Causality and ERA-5 based Approach in Assessing the Impact of ENSO and Climate Variability on Extreme Events in India

Nonlinear Granger Causality and ERA-5 based Approach in Assessing the Impact of ENSO and Climate Variability on Extreme Events in India | 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 Nonlinear Granger Causality and ERA-5 based Approach in Assessing the Impact of ENSO and Climate Variability on Extreme Events in India Jahnavi Singh, Manish Kumar, Akash Tiwari, Swati Thakur This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4583350/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Over the past few decades, there has been a significant emphasis among hydro-climatologists on understanding the intricate teleconnections that exist between the El Niño Southern Oscillation (ENSO) and various hydro-meteorological phenomena, such as droughts and floods. Large-scale climatic circulation patterns like ENSO have a profound impact on both global and regional hydrometeorological events. India is also experiencing frequent droughts as a significant climatic calamity; thus, knowing these teleconnections at the physiographical division level would be highly beneficial in improved drought management and planning. In the present study, the long-term trend of meteorological drought was evaluated by two drought indices, viz., the Standardised Precipitation Evapotranspiration Index (SPEI) and the Standardised Precipitation Index (SPI), at time scales of 3, 6, 9, and 12 months using the Modified Mann-Kendall (MMK) Test and Innovative Trend Analysis (ITA) for the period 1901–2021. Furthermore, this study used the Non-linear Granger Causality Test (NGCT) due to its ability to identify complex and nonlinear relationships among variables to investigate the teleconnection between the drought indices and four climate indices (Southern Oscillation Index, Northern Oscillation Index, NINO 3, and NINO 3.4) from 1951 to 2021. ECMWF (European Centre for Medium-Range Weather Forecasts) ReAnalysis v.5 (ERA-5) data was used to explore the major climatic cause of the drought. According to the MMK test, the north Deccan and western coast regions show the most significant positive trend in SPEI 12 and SPEI 3 (0.071 and 0.078, respectively), as well as SPI 12 (0.072 and 0.098). In contrast, only the Himalayan region shows the most significant negative trend of -0.205 for SPEI 12 and SPI 12, respectively. Additionally, results from the MMK test and ITA indicate an increasing risk of drought in the Great Indian Desert, eastern and western coasts, and northern and southern Deccan regions. However, a decreasing trend was observed in the Himalayan and Northern Plain regions. The study emphasises that the effect of ENSO on evapotranspiration-based drought (i.e., computed using SPEI) is more significant than precipitation-based drought (i.e., computed using SPI). According to ERA-5 reanalysis data, changes in convective precipitation and rainfall rate, low cloud cover, insufficient vertical moisture divergence, and decreased snowfall rate all contributed to drought in a few locations in India. ENSO Teleconnection Granger Modified Mann-Kendall Innovative Trend Analysis ERA-5 Reanalysis Full Text Supplementary Files SupplementaryMaterials.docx Cite Share Download PDF Status: Posted Version 1 posted 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-4583350","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":317470023,"identity":"c1c22d96-5e71-4186-9251-ea899e87a6bb","order_by":0,"name":"Jahnavi Singh","email":"","orcid":"","institution":"Central University of Haryana","correspondingAuthor":false,"prefix":"","firstName":"Jahnavi","middleName":"","lastName":"Singh","suffix":""},{"id":317470024,"identity":"8688ec8a-5bb7-4d89-bdf1-ff2311b472e0","order_by":1,"name":"Manish Kumar","email":"","orcid":"","institution":"Central University of Haryana","correspondingAuthor":false,"prefix":"","firstName":"Manish","middleName":"","lastName":"Kumar","suffix":""},{"id":317470025,"identity":"9caf16c8-0b88-482e-aea7-38625821b59b","order_by":2,"name":"Akash Tiwari","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABEUlEQVRIiWNgGAWjYBCDBAYeBgZmEIsfzC0gRYtkA4hrQIoWgwNgErdS8/b2hw9+7rHL4+85/PhzwS8bOePzqxM/PDBgkOcXO4BVi8yZM8aGPc+SiyXOtplJz+xLMza78XazBNBhhjNnJ2DVIiGRwybBc+BAYsN5BjNm3p7DidtunN0A0pJgcBuHFvnnz3/+AWqZf57982fenv+Jm2ec3fwDrxYJoOEgWzac7TGQ5vkBZPD3bsNvC0+OsbTMgeTEjWfOlEnzNiQbS9zg3WaRYCCB2y/sxx9+fHPALnHemfTNn3n+2Mnx95/dfPNHhY08vzR2LaiAsQ1kClilBBHKweAPEPMfIFb1KBgFo2AUjBAAAJ9VZbiWyNLKAAAAAElFTkSuQmCC","orcid":"","institution":"Central University of Haryana","correspondingAuthor":true,"prefix":"","firstName":"Akash","middleName":"","lastName":"Tiwari","suffix":""},{"id":317470026,"identity":"0b7e0517-b4ec-45e8-b34b-ea65c4e2b543","order_by":3,"name":"Swati Thakur","email":"","orcid":"","institution":"Dyal Singh College","correspondingAuthor":false,"prefix":"","firstName":"Swati","middleName":"","lastName":"Thakur","suffix":""}],"badges":[],"createdAt":"2024-06-14 16:49:49","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4583350/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4583350/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":87234353,"identity":"077ee339-a020-4db9-a1bd-6b8ec68e7ddb","added_by":"auto","created_at":"2025-07-21 20:40:40","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1986337,"visible":true,"origin":"","legend":"","description":"","filename":"CompleteManuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4583350/v1_covered_b8bc6aa6-a385-4f22-b320-bac4ce18370d.pdf"},{"id":60132336,"identity":"91c1d82d-3d79-4d8b-888d-209c8d5e4c47","added_by":"auto","created_at":"2024-07-12 07:21:31","extension":"docx","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":16460947,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryMaterials.docx","url":"https://assets-eu.researchsquare.com/files/rs-4583350/v1/4ec46ca7eda3e2653c5d71de.docx"}],"financialInterests":"","formattedTitle":"Nonlinear Granger Causality and ERA-5 based Approach in Assessing the Impact of ENSO and Climate Variability on Extreme Events in India","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"ENSO, Teleconnection, Granger, Modified Mann-Kendall, Innovative Trend Analysis, ERA-5 Reanalysis","lastPublishedDoi":"10.21203/rs.3.rs-4583350/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4583350/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eOver the past few decades, there has been a significant emphasis among hydro-climatologists on understanding the intricate teleconnections that exist between the El Ni\u0026ntilde;o Southern Oscillation (ENSO) and various hydro-meteorological phenomena, such as droughts and floods. 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