Regional Structure of the Polar Vortex via Planetary Wave Phase Diagnostics and Its Link to Cold Air Outbreaks

Regional Structure of the Polar Vortex via Planetary Wave Phase Diagnostics and Its Link to Cold Air Outbreaks | 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 Regional Structure of the Polar Vortex via Planetary Wave Phase Diagnostics and Its Link to Cold Air Outbreaks Varunesh Chandra, Muyin Wang, James E. Overland This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7553307/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 24 Apr, 2026 Read the published version in npj Climate and Atmospheric Science → Version 1 posted 10 You are reading this latest preprint version Abstract Extreme winter cold-air outbreaks (CAOs) disrupt societies and economies across the Northern Hemisphere, yet the stratospheric pathways that organize these events—and their regional expression—remain incompletely understood. While prior studies often emphasize North American impacts using cluster-based approaches, disruptions of the lower stratospheric polar vortex (LSPV)—through displacement or stretching—can shape weather across the wider subarctic and midlatitudes. We present a framework to diagnose daily LSPV variability using the variance, amplitude and longitudinal phase of zonal wave-1 and wave-2 spectral components derived from 100 hPa geopotential height anomalies. Applying zonal harmonic decomposition on band-averaged geopotential height anomalies at100 hPa, we separate SPV structure into wave-1 (displacement) and wave-2 (stretching) modes. This analysis reveals four persistent, regionally anchored vortex trough phase orientations—over North America, the Atlantic, Asia, and the Far East—that reflect quasi-stationary planetary wave geometry and recurring large-scale weather regimes. Composite analysis demonstrates vertically coherent structures extending from the lower stratosphere to the surface, with distinct 500 hPa trough anomalies and associated surface CAOs. A transition probability matrix show that the SPV undergoes rapid spatial reorganization rather than slow longitudinal advection. These results demonstrate that vortex displacement and stretching are fundamental, recurring features of Arctic and subarctic atmospheric variability, providing a new approach for diagnosing and predicting midlatitude extremes under ongoing Arctic amplification. Earth and environmental sciences/Climate sciences Physical sciences/Physics Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 24 Apr, 2026 Read the published version in npj Climate and Atmospheric Science → Version 1 posted Editorial decision: Revision requested 03 Oct, 2025 Reviews received at journal 30 Sep, 2025 Reviewers agreed at journal 30 Sep, 2025 Reviews received at journal 30 Sep, 2025 Reviewers agreed at journal 15 Sep, 2025 Reviewers agreed at journal 13 Sep, 2025 Reviewers invited by journal 12 Sep, 2025 Editor assigned by journal 12 Sep, 2025 Submission checks completed at journal 12 Sep, 2025 First submitted to journal 06 Sep, 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. 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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-7553307","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":516732937,"identity":"518e4620-80ff-4cc0-95a4-819e30bbbf73","order_by":0,"name":"Varunesh Chandra","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAqklEQVRIiWNgGAWjYBCDBH4wxUaKFskGkrUYHCBWi8Hxs8+kCyrq8oxv5BgwfCg7TISWM+lm0jPOHC42A2phnHGOCC2SDWls0rxtBxK33cjdwMzbRoyW/mdALf/qEjfPAGr5S4wWfgmQLQ3MiRskgFoYidPyjNma59jhxBln3n842HMunbAWNv40xts8NXWJ/e1piQ9+lFkT1oICDpCofhSMglEwCkYBLgAAixc4M6511BcAAAAASUVORK5CYII=","orcid":"","institution":"University of Washington","correspondingAuthor":true,"prefix":"","firstName":"Varunesh","middleName":"","lastName":"Chandra","suffix":""},{"id":516732939,"identity":"7509fb63-65c3-489f-8def-9ddc87a37580","order_by":1,"name":"Muyin Wang","email":"","orcid":"","institution":"University of Washington","correspondingAuthor":false,"prefix":"","firstName":"Muyin","middleName":"","lastName":"Wang","suffix":""},{"id":516732941,"identity":"bef49a74-7a72-4ad2-8268-ea8c9c8b18b2","order_by":2,"name":"James E. 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While prior studies often emphasize North\nAmerican impacts using cluster-based approaches, disruptions of the lower stratospheric polar\nvortex (LSPV)—through displacement or stretching—can shape weather across the wider\nsubarctic and midlatitudes. We present a framework to diagnose daily LSPV variability using the\nvariance, amplitude and longitudinal phase of zonal wave-1 and wave-2 spectral components\nderived from 100 hPa geopotential height anomalies. Applying zonal harmonic decomposition on\nband-averaged geopotential height anomalies at100 hPa, we separate SPV structure into wave-1\n(displacement) and wave-2 (stretching) modes. This analysis reveals four persistent, regionally\nanchored vortex trough phase orientations—over North America, the Atlantic, Asia, and the Far\nEast—that reflect quasi-stationary planetary wave geometry and recurring large-scale weather\nregimes. Composite analysis demonstrates vertically coherent structures extending from the lower\nstratosphere to the surface, with distinct 500 hPa trough anomalies and associated surface CAOs.\nA transition probability matrix show that the SPV undergoes rapid spatial reorganization rather\nthan slow longitudinal advection. These results demonstrate that vortex displacement and\nstretching are fundamental, recurring features of Arctic and subarctic atmospheric variability,\nproviding a new approach for diagnosing and predicting midlatitude extremes under ongoing\nArctic amplification.","manuscriptTitle":"Regional Structure of the Polar Vortex via Planetary Wave Phase Diagnostics and Its Link to Cold Air Outbreaks","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-22 13:02:32","doi":"10.21203/rs.3.rs-7553307/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-10-03T22:03:20+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-30T19:56:11+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"58405755319367060296880210261940501194","date":"2025-09-30T12:24:58+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-30T08:36:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"35806863486287290490307861859308522387","date":"2025-09-15T08:53:22+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"81309138759391375621825361843012974098","date":"2025-09-13T08:18:56+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-12T21:54:57+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-12T11:34:36+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-12T10:16:28+00:00","index":"","fulltext":""},{"type":"submitted","content":"npj Climate and Atmospheric Science","date":"2025-09-06T23:53:13+00:00","index":"","fulltext":""}],"status":"published","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}}],"origin":"","ownerIdentity":"637e5464-0ae0-4ae4-a9ab-42e261ed3403","owner":[],"postedDate":"September 22nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":54904507,"name":"Earth and environmental sciences/Climate sciences"},{"id":54904508,"name":"Physical sciences/Physics"}],"tags":[],"updatedAt":"2026-04-27T16:00:42+00:00","versionOfRecord":{"articleIdentity":"rs-7553307","link":"https://doi.org/10.1038/s41612-026-01418-4","journal":{"identity":"npj-climate-and-atmospheric-science","isVorOnly":false,"title":"npj Climate and Atmospheric Science"},"publishedOn":"2026-04-24 15:57:28","publishedOnDateReadable":"April 24th, 2026"},"versionCreatedAt":"2025-09-22 13:02:32","video":"","vorDoi":"10.1038/s41612-026-01418-4","vorDoiUrl":"https://doi.org/10.1038/s41612-026-01418-4","workflowStages":[]},"version":"v1","identity":"rs-7553307","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7553307","identity":"rs-7553307","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}