Nonlinear Precipitation Patterns in the Mediterranean and Middle East: Insights from ERA5 Reanalysis (1940–2025)

Nonlinear Precipitation Patterns in the Mediterranean and Middle East: Insights from ERA5 Reanalysis (1940–2025) | 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 Precipitation Patterns in the Mediterranean and Middle East: Insights from ERA5 Reanalysis (1940–2025) Hasan TATLI This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6421314/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 07 Jul, 2025 Read the published version in Environmental Earth Sciences → Version 1 posted 7 You are reading this latest preprint version Abstract This study investigates the spatial, multifractal, and nonlinear characteristics of monthly precipitation totals derived from the ERA5 Reanalysis dataset, spanning January 1940 to February 2025 (1,022 months), across the Mediterranean and Middle East (30°N–45°N, 10°E–45°E). The dataset, subsampled to a 1° × 1° grid encompassing 576 grid points, captures long-term precipitation variability in a climatically diverse region shaped by topography and atmospheric dynamics. Employing k-Medoids clustering with the Haversine distance metric, we delineated five distinct precipitation zones—ranging from western Mediterranean coastal areas to eastern inland arid deserts—optimized through Silhouette Score analysis (k = 5). This clustering reflects the complex interplay of physical geographical features, such as orographic lift from the Alps and Taurus Mountains, and atmospheric controls, including jet streams and teleconnections. Multifractal Detrended Fluctuation Analysis (MF-DFA) revealed scale-dependent complexity, with multifractal spectrum widths \(\:D\alpha\:\) varying from 0.7960 in eastern arid interiors (Cluster 5) to 0.9159 in central semi-arid Mediterranean zones (Cluster 2). Mountainous regions (Cluster 3, Dα = 0.8544) exhibited pronounced multifractality, driven by terrain-induced variability and seasonal convection. Concurrently, the Brock-Dechert-Scheinkman (BDS) test confirmed pervasive nonlinearity across all clusters, yielding p-values < 0.05 and BDS statistics ranging from 33.5044 (Cluster 5) to 55.8214 (Cluster 3). These results attest to chaotic atmospheric processes, including orographic effects, convective phenomena, and teleconnections like the North Atlantic Oscillation (NAO) and Mediterranean Oscillation (MO). The analysis further elucidated spatial dependencies and upper air circulation patterns—jet streams, cyclonic/anticyclonic systems—as key modulators of precipitation regimes, validated against ERA5 reanalysis data. These findings enhance understanding of long-term precipitation variability, offering a robust framework for improving climate modeling, drought and flood forecasting, and water resource management in a region highly susceptible to climate change. By integrating advanced statistical methods with ERA5’s extensive temporal coverage, this study provides critical insights into atmospheric science, with significant implications for regional sustainability, disaster preparedness, and meteorological research. Precipitation dynamics ERA5 Reanalysis multifractal analysis nonlinearity k-Medoids clustering Mediterranean Middle East climate variability teleconnections orographic effects Full Text Additional Declarations Competing interest reported. The author declares no conflicts of interest associated with this research. Cite Share Download PDF Status: Published Journal Publication published 07 Jul, 2025 Read the published version in Environmental Earth Sciences → Version 1 posted Editorial decision: Revision requested 07 Jun, 2025 Reviews received at journal 05 Jun, 2025 Reviewers agreed at journal 08 May, 2025 Reviewers invited by journal 07 May, 2025 Editor assigned by journal 15 Apr, 2025 Submission checks completed at journal 15 Apr, 2025 First submitted to journal 10 Apr, 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. 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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-6421314","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":443370643,"identity":"a87d458a-c779-4df0-9186-e868daa84562","order_by":0,"name":"Hasan TATLI","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAtklEQVRIiWNgGAWjYHACxgMJFVAmDzHqeRiYGQ4knEFokSBOC2MbKVrs2c8fOPBwnp2c7owExgdv2xjqzBsI2cKTzHAgcVuysdmNBGbDuW0MEjIHCDoMrAWIbiSwSfMCtRB0GQ//Y6CWOWAt7L+J0yIBsqUBYgszcVpuPDY4kHAM6JczD5sl55yTkJxBSAt7f+LDhz9q7OTMjicf/PCmzIafcCgjAGMDAzHRMgpGwSgYBaOACAAAP5w75lgOHioAAAAASUVORK5CYII=","orcid":"","institution":"Çanakkale Onsekiz Mart University","correspondingAuthor":true,"prefix":"","firstName":"Hasan","middleName":"","lastName":"TATLI","suffix":""}],"badges":[],"createdAt":"2025-04-10 14:53:23","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6421314/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6421314/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s12665-025-12412-z","type":"published","date":"2025-07-07T15:57:14+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":86699466,"identity":"a240878b-72fe-44de-b627-6bd946f59fa2","added_by":"auto","created_at":"2025-07-14 16:10:07","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":957222,"visible":true,"origin":"","legend":"","description":"","filename":"Maindoc.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6421314/v1_covered_04613060-197f-4aa9-8e8d-69806f1f7314.pdf"}],"financialInterests":"Competing interest reported. 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The dataset, subsampled to a 1\u0026deg; \u0026times; 1\u0026deg; grid encompassing 576 grid points, captures long-term precipitation variability in a climatically diverse region shaped by topography and atmospheric dynamics. Employing k-Medoids clustering with the Haversine distance metric, we delineated five distinct precipitation zones\u0026mdash;ranging from western Mediterranean coastal areas to eastern inland arid deserts\u0026mdash;optimized through Silhouette Score analysis (k\u0026thinsp;=\u0026thinsp;5). This clustering reflects the complex interplay of physical geographical features, such as orographic lift from the Alps and Taurus Mountains, and atmospheric controls, including jet streams and teleconnections.\u003c/p\u003e \u003cp\u003eMultifractal Detrended Fluctuation Analysis (MF-DFA) revealed scale-dependent complexity, with multifractal spectrum widths \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:D\\alpha\\:\\)\u003c/span\u003e\u003c/span\u003e varying from 0.7960 in eastern arid interiors (Cluster 5) to 0.9159 in central semi-arid Mediterranean zones (Cluster 2). Mountainous regions (Cluster 3, Dα\u0026thinsp;=\u0026thinsp;0.8544) exhibited pronounced multifractality, driven by terrain-induced variability and seasonal convection. Concurrently, the Brock-Dechert-Scheinkman (BDS) test confirmed pervasive nonlinearity across all clusters, yielding p-values\u0026thinsp;\u0026lt;\u0026thinsp;0.05 and BDS statistics ranging from 33.5044 (Cluster 5) to 55.8214 (Cluster 3). These results attest to chaotic atmospheric processes, including orographic effects, convective phenomena, and teleconnections like the North Atlantic Oscillation (NAO) and Mediterranean Oscillation (MO).\u003c/p\u003e \u003cp\u003eThe analysis further elucidated spatial dependencies and upper air circulation patterns\u0026mdash;jet streams, cyclonic/anticyclonic systems\u0026mdash;as key modulators of precipitation regimes, validated against ERA5 reanalysis data. These findings enhance understanding of long-term precipitation variability, offering a robust framework for improving climate modeling, drought and flood forecasting, and water resource management in a region highly susceptible to climate change. By integrating advanced statistical methods with ERA5\u0026rsquo;s extensive temporal coverage, this study provides critical insights into atmospheric science, with significant implications for regional sustainability, disaster preparedness, and meteorological research.\u003c/p\u003e","manuscriptTitle":"Nonlinear Precipitation Patterns in the Mediterranean and Middle East: Insights from ERA5 Reanalysis (1940–2025)","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-05 04:17:35","doi":"10.21203/rs.3.rs-6421314/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-06-07T12:44:54+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-05T20:49:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"104484111175551060401944359017915124573","date":"2025-05-08T20:23:27+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-05-07T23:38:15+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-04-15T15:08:27+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-15T15:05:36+00:00","index":"","fulltext":""},{"type":"submitted","content":"Environmental Earth Sciences","date":"2025-04-10T14:50:30+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"environmental-earth-sciences","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"enge","sideBox":"Learn more about [Environmental Earth Sciences](https://www.springer.com/journal/12665)","snPcode":"12665","submissionUrl":"https://submission.nature.com/new-submission/12665/3","title":"Environmental Earth Sciences","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"8c794bbd-a9a2-4396-895a-08c1083a0d52","owner":[],"postedDate":"May 5th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-07-14T16:04:51+00:00","versionOfRecord":{"articleIdentity":"rs-6421314","link":"https://doi.org/10.1007/s12665-025-12412-z","journal":{"identity":"environmental-earth-sciences","isVorOnly":false,"title":"Environmental Earth Sciences"},"publishedOn":"2025-07-07 15:57:14","publishedOnDateReadable":"July 7th, 2025"},"versionCreatedAt":"2025-05-05 04:17:35","video":"","vorDoi":"10.1007/s12665-025-12412-z","vorDoiUrl":"https://doi.org/10.1007/s12665-025-12412-z","workflowStages":[]},"version":"v1","identity":"rs-6421314","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6421314","identity":"rs-6421314","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}