A basin-wide Arctic ice shelf reverses deep ocean circulation

A basin-wide Arctic ice shelf reverses deep ocean circulation | 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 A basin-wide Arctic ice shelf reverses deep ocean circulation Pengyang Song, Gregor Knorr, Gerrit Lohmann This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8848433/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Geological evidence suggests that a kilometre-thick ice shelf may have covered the Arctic Mediterranean (AM)—comprising the Arctic Ocean and Nordic Seas—during one or more glacial periods. However, the broader climatic and oceanographic implications of such a scenario remain poorly understood. Here, for the first time, we use a comprehensive Earth system model that explicitly resolves sub-ice-shelf circulation to explore the consequences of a fully glaciated AM. Our simulations reveal a fundamentally altered glacial ocean state: the expansive ice shelf reverses the overturning circulation within the AM—from dense-water sinking to deep-water upwelling—and suppresses North Atlantic Deep Water formation through sustained meltwater discharge from the AM. The persistent connection between the AM and the North Atlantic is maintained by a continuous Atlantic inflow through the Faroe–Shetland Channel, which prevents the AM from freshening. Hence, our results do not support the previously proposed hypothesis that freshwater could have accumulated beneath such a gigantic ice shelf, underscoring the critical role of ice shelf–ocean interactions in shaping glacial deep-water circulation. Earth and environmental sciences/Climate sciences/Palaeoclimate Earth and environmental sciences/Ocean sciences/Physical oceanography Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Under Review 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. 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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-8848433","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":595482540,"identity":"f7548c37-17a9-473f-b696-b06f7c9f2c2f","order_by":0,"name":"Pengyang Song","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+UlEQVRIiWNgGAWjYBAC+wYYi/8AkKhgYGBjYDDAq8XgAIwlkQAkzpCmBYgZ2yCC+LUc7z38mqfmjl2DBPOxh1/n2SX2MTBvfIBPi33PuTRrnmPPkhv4j6Uby25LTmxjYCvGa42BRI6ZMQ/b4WQGhhwzacltzLltDDxmEni1yL8BavkH0zKnHqTF/Ad+W3iMH/O2HbYDaZH82HAYbAs+HQwGPDlmjHP7DiewSaSlSTMcO17fxsxWjN9h7GeMP7z5dtien//wMckfNdXG8u3NGz/gtQYYd1I8DAyJoBhh5gHxmQmoByn5CPStPYjFiNfbo2AUjIJRMGIBAGTERneKKCAHAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0003-1791-9454","institution":"Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research","correspondingAuthor":true,"prefix":"","firstName":"Pengyang","middleName":"","lastName":"Song","suffix":""},{"id":595482541,"identity":"a3f2cdb9-1cee-4eeb-8b12-cc38d208031c","order_by":1,"name":"Gregor Knorr","email":"","orcid":"https://orcid.org/0000-0002-8317-5046","institution":"Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research","correspondingAuthor":false,"prefix":"","firstName":"Gregor","middleName":"","lastName":"Knorr","suffix":""},{"id":595482542,"identity":"02f8d6a8-fe01-4c4d-a469-7543aec731aa","order_by":2,"name":"Gerrit Lohmann","email":"","orcid":"https://orcid.org/0000-0003-2089-733X","institution":"Alfred Wegener Institute","correspondingAuthor":false,"prefix":"","firstName":"Gerrit","middleName":"","lastName":"Lohmann","suffix":""}],"badges":[],"createdAt":"2026-02-11 07:25:32","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8848433/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8848433/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":103507304,"identity":"76387a00-624d-420f-b5fe-1caa8a2c97fd","added_by":"auto","created_at":"2026-02-26 13:40:57","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":9029404,"visible":true,"origin":"","legend":"Article File","description":"","filename":"AglaciatedArcticMediterranean.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8848433/v1_covered_3b66fe5a-6fde-4f83-a706-40f6bcddb95c.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"A basin-wide Arctic ice shelf reverses deep ocean circulation","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"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":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-8848433/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8848433/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Geological evidence suggests that a kilometre-thick ice shelf may have covered the Arctic Mediterranean (AM)—comprising the Arctic Ocean and Nordic Seas—during one or more glacial periods. 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