Uncovering Missing Eurasian Blocking Events and Their Robust Role in East Asian Winter Extremes

Uncovering Missing Eurasian Blocking Events and Their Robust Role in East Asian Winter Extremes | 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 Article Uncovering Missing Eurasian Blocking Events and Their Robust Role in East Asian Winter Extremes Hayeon Noh, Ho-Young Ku, Mi-Kyung Sung, Baek-Min Kim This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8639352/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 27 Apr, 2026 Read the published version in npj Climate and Atmospheric Science → Version 1 posted 10 You are reading this latest preprint version Abstract Despite the profound influence of Eurasian blocking on the East Asian winter monsoon, its objective detection remains a challenge due to a systematic under-detection in standard algorithms. The widely adopted Hybrid method (HYB) applies a hemispheric constant threshold for anomaly detection prior to the flow reversal criterion. This constrained design neglects the lower geopotential height variability characteristic of the Eurasian continent, resulting in the premature filtering of meteorologically significant events. Here, we propose the Regional Hybrid method (RHYB), a refined framework that incorporates anomaly thresholds tailored to local geopotential height variance. By reconciling detection criteria with regional physical characteristics, RHYB explicitly captures "reversal-dominated" systems—events with clear flow disruption but modest amplitude—that were previously obscured. Using ERA5 reanalysis, we demonstrate that these newly identified events are robust drivers of severe wintertime cold surges over East Asia, indicating that their prior omission has led to a significant underestimation of regional climate risks. These results underscore that RHYB is an essential tool for accurately diagnosing midlatitude extremes and their evolving dynamics in a warming world. Earth and environmental sciences/Climate sciences Earth and environmental sciences/Natural hazards Full Text Additional Declarations No competing interests reported. Supplementary Files Supplementary.docx Cite Share Download PDF Status: Published Journal Publication published 27 Apr, 2026 Read the published version in npj Climate and Atmospheric Science → Version 1 posted Editorial decision: Revision requested 20 Feb, 2026 Reviews received at journal 15 Feb, 2026 Reviews received at journal 10 Feb, 2026 Reviewers agreed at journal 30 Jan, 2026 Reviewers agreed at journal 27 Jan, 2026 Reviewers agreed at journal 26 Jan, 2026 Reviewers invited by journal 25 Jan, 2026 Editor assigned by journal 23 Jan, 2026 Submission checks completed at journal 23 Jan, 2026 First submitted to journal 19 Jan, 2026 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. 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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-8639352","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":594666643,"identity":"538aca33-3f4a-4c3a-8613-da15fb057006","order_by":0,"name":"Hayeon Noh","email":"","orcid":"","institution":"Korea Institute of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Hayeon","middleName":"","lastName":"Noh","suffix":""},{"id":594666645,"identity":"8ab878a6-1ed0-40ec-b048-9c06b21baf31","order_by":1,"name":"Ho-Young Ku","email":"","orcid":"","institution":"Pukyong National University","correspondingAuthor":false,"prefix":"","firstName":"Ho-Young","middleName":"","lastName":"Ku","suffix":""},{"id":594666646,"identity":"864d0549-32b3-40ab-8c4d-fa7ffc1d1cde","order_by":2,"name":"Mi-Kyung Sung","email":"","orcid":"","institution":"Korea Institute of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Mi-Kyung","middleName":"","lastName":"Sung","suffix":""},{"id":594666649,"identity":"7b755b2b-8c0f-4800-ba04-53a76b10b3ec","order_by":3,"name":"Baek-Min Kim","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA0klEQVRIiWNgGAWjYBACAwYGZhApx8ADFZEgVosxqVoYGBIbiNZizn74sNGNgjvp23nOHpNgqLFjkJx9AL8Wy5605OQcg2e5O3v70iQYjiUzSPMlEHDYgRzjwzkGh3M3nOcxk2BgO8Agx4NfB4PB+fefQVrSDcBa/hGj5UYOM9BhhxMMzvaYSTC2HWCQJqTFcsYzY2OgFsOdPWeMLRL7knkkewhoMedPfiyd8+ewvDlPjuGND9/s5CTOENCCcCGISGBgIOQsdC2jYBSMglEwCrABAN5SO9CkNg6EAAAAAElFTkSuQmCC","orcid":"","institution":"Pukyong National University","correspondingAuthor":true,"prefix":"","firstName":"Baek-Min","middleName":"","lastName":"Kim","suffix":""}],"badges":[],"createdAt":"2026-01-19 12:12:50","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8639352/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8639352/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41612-026-01415-7","type":"published","date":"2026-04-27T15:57:03+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":108437965,"identity":"df7c4e1c-cd3f-4cb9-8c64-cb94fc8b558e","added_by":"auto","created_at":"2026-05-04 16:04:55","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1442476,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8639352/v1_covered_c2517809-dd4b-4a5c-9b75-6d285e11d484.pdf"},{"id":104467212,"identity":"51a55386-7cf7-4e86-82d2-5820b5efb5ab","added_by":"auto","created_at":"2026-03-12 06:30:03","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":807299,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementary.docx","url":"https://assets-eu.researchsquare.com/files/rs-8639352/v1/50ef34112ee42538c0b4e60e.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Uncovering Missing Eurasian Blocking Events and Their Robust Role in East Asian Winter Extremes","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":true,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"npj-climate-and-atmospheric-science","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"npjclimatsci","sideBox":"Learn more about [npj Climate and Atmospheric Science](http://www.nature.com/npjclimatsci/)","snPcode":"41612","submissionUrl":"https://submission.springernature.com/new-submission/41612/3","title":"npj Climate and Atmospheric Science","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"NPJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-8639352/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8639352/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eDespite the profound influence of Eurasian blocking on the East Asian winter monsoon, its objective detection remains a challenge due to a systematic under-detection in standard algorithms. 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