A dynamical interpretation of the intensification of the winter North Atlantic jet stream in reanalysis

A dynamical interpretation of the intensification of the winter North Atlantic jet stream in reanalysis | 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 A dynamical interpretation of the intensification of the winter North Atlantic jet stream in reanalysis Alejandro Hermoso Verger, Gwendal Riviere, Ben Harvey, John Methven, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3201851/v3 This work is licensed under a CC BY 4.0 License Status: Posted Version 3 posted You are reading this latest preprint version Show more versions Abstract Jet streams play an important role in determining weather variability and extremes. A better understanding of the mechanisms driving long-term changes in the jet is essential to successfully anticipate extreme meteorological events. This study analyzes the intensification trend of the North Atlantic jet using the ERA5 reanalysis and investigates the dynamical mechanisms involved. The results highlight the importance of an increase in diabatic heating in the free troposphere below the jet entrance over the Gulf Stream sector. This change in diabatic heating modifies the jet directly and produces a local intensification and a slight poleward shift. A two-dimensional frontal-geostrophic model illustrates this mechanism by considering the enhanced diabatic heating associated with the baroclinic growth of extratropical cyclones. The change in diabatic heating also affects the jet indirectly by increasing the mean baroclinicity and subsequent eddy momentum flux convergence. This indirect mechanism has also an effect downstream, where there is an acceleration of the jet core and reduced westerlies along the flanks, reducing the width of the jet. An idealized warming experiment confirms this mechanism by determining the jet response downstream of an idealized land-sea contrast. Finally, using a single-model ensemble of fully-coupled climate simulations, we show that the differences in the evolution of the North Atlantic jet are related to the latitude of the increase in baroclinicity, which has a large spread. What emerges from the model hierarchy is a consistent dynamical chain of mechanisms associated with the intensification trend of the North Atlantic jet stream. Earth and environmental sciences/Climate sciences/Atmospheric science/Atmospheric dynamics Earth and environmental sciences/Climate sciences/Climate change/Projection and prediction Earth and environmental sciences/Climate sciences/Climate change/Climate and Earth system modelling Full Text Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 3 posted You are reading this latest preprint version Show more versions 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-3201851","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":265051767,"identity":"6103c889-4a86-47b1-a025-a9cf88a06e8f","order_by":0,"name":"Alejandro Hermoso Verger","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABLklEQVRIie2RMUvDQBTHXwgky9VbLxT1K7wjkFJa7FeJFJKlYEddJCWQqe4tfolOwTHhoC6VroqLEOgmpBSEDqJHQoeSs7PD/ZZ3/O9+vHd3ABrNf8QGQABTrsghieoq4ypvYDYUklWFnVLgWGH+aYXGZjbeP/VuKLTy4m7UH1CnWBYE+vcdmhm7cVNhwvL5wyrszqOzIX9Jg+v5YxC6BALWjTKzPVO0EQSxlQjEjHjOJBU+vo88ZwaCYR5ZJmkal4KW/LtWOnupDPBt/SWVH4YClAoKAu6hiyEVY/FKLFZCxnCpVriw0D1PQnRi4srB5F2mgcdKHDqLlRG3FcrFc7zhn0kPqT3l20kqX8wWG+bfXlFci3ynUCQWVuX4C6rMiJSCPPvxx4ZGo9Foan4BhtRcAn3ZfFcAAAAASUVORK5CYII=","orcid":"","institution":"ETH Zürich","correspondingAuthor":true,"prefix":"","firstName":"Alejandro","middleName":"Hermoso","lastName":"Verger","suffix":""},{"id":265051768,"identity":"8c018d4f-e9d7-43c7-ac16-7b638d0640f4","order_by":1,"name":"Gwendal Riviere","email":"","orcid":"https://orcid.org/0000-0002-6056-5973","institution":"Ecole Normale Superieure","correspondingAuthor":false,"prefix":"","firstName":"Gwendal","middleName":"","lastName":"Riviere","suffix":""},{"id":265051769,"identity":"fcde87c8-1d1e-447e-9ada-df24ddf1c6ef","order_by":2,"name":"Ben Harvey","email":"","orcid":"","institution":"Department of Meteorology, University of Reading","correspondingAuthor":false,"prefix":"","firstName":"Ben","middleName":"","lastName":"Harvey","suffix":""},{"id":265051770,"identity":"f6b81f9d-ade8-4275-bdc3-7b1f8fee916b","order_by":3,"name":"John Methven","email":"","orcid":"https://orcid.org/0000-0002-7636-6872","institution":"","correspondingAuthor":false,"prefix":"","firstName":"John","middleName":"","lastName":"Methven","suffix":""},{"id":265051771,"identity":"c17456a2-27cb-4995-b784-f6f11e213d59","order_by":4,"name":"Sebastian Schemm","email":"","orcid":"https://orcid.org/0000-0002-1601-5683","institution":"ETH Zurich","correspondingAuthor":false,"prefix":"","firstName":"Sebastian","middleName":"","lastName":"Schemm","suffix":""}],"badges":[],"createdAt":"2023-07-25 07:36:07","currentVersionCode":3,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-3201851/v3","doiUrl":"https://doi.org/10.21203/rs.3.rs-3201851/v3","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":56205696,"identity":"ed4dc0ca-0408-4ecc-afa6-b61493056656","added_by":"auto","created_at":"2024-05-09 21:19:42","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4399753,"visible":true,"origin":"","legend":"","description":"","filename":"HermosoetalsubmittedtoJClimate.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3201851/v3_covered_212791c7-7e5e-40d2-ab3b-8f51fbefbac2.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003eA dynamical interpretation of the intensification of the winter North Atlantic jet stream in reanalysis\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"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":"","lastPublishedDoi":"10.21203/rs.3.rs-3201851/v3","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3201851/v3","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eJet streams play an important role in determining weather variability and extremes. 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