North Atlantic influence reconciling model-observation discrepancy in the tropical Pacific warming pattern

North Atlantic influence reconciling model-observation discrepancy in the tropical Pacific warming pattern | 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 North Atlantic influence reconciling model-observation discrepancy in the tropical Pacific warming pattern Yueh-Chi Lin, Masahiro Watanabe This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7059131/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 Over the past four decades, zonal contrast in the tropical Pacific sea surface temperature (SST) has strengthened in observations but weakened in majority of climate model simulations. This model–observation discrepancy cannot be explained by internal mode of interdecadal climate variability in the Pacific alone, and the source of possible model errors remains unclear. Here, using observations and a large ensemble of historical simulations by a climate model, we identified that the simulated SST pattern associated with the Atlantic Multidecadal Variability (AMV) is biased in the tropical Pacific despite the time evolution of the AMV being reproduced well. Observations suggest that the positive AMV acts to increase the Pacific zonal SST contrast whereas this teleconnection process falsely weakens it in the model, which is a common feature in other climate models, and correcting the AMV-related SST pattern, which is likely an externally forced response, partly reconciles the model-observation discrepancy. Earth and environmental sciences/Climate sciences/Climate change/Attribution Earth and environmental sciences/Climate sciences/Climate change/Projection and prediction Full Text Additional Declarations There is NO Competing Interest. Supplementary Files NCLIMSupplementaryfinalYC.docx Supplementary Figures and Table 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. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-7059131","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":483122831,"identity":"1f6aec17-5a4c-4232-9f80-feb2e88c99f1","order_by":0,"name":"Yueh-Chi Lin","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABDklEQVRIie3QMWuDQBTA8ScpZnnU9UkK9iOcCEIpJF9FONBF6BpoIE52CWT14wgH53LN7JAhk1MGp9Kl0ItpSgqX0LHQ+4N4PP1xngA229/M1VeN3mGZfA+G6uvEL74I/pYAOz0/I+ZYy+UOFtu7qBGy34GA2bhMqYdpAM6rcRvWphkD2WGsUl4lmiBK6VfAwwI2iZnk8eSjEBjXeaTPIpYrysoJwki/rpiZPL2Ro0m03g8E8EiWV0juDoRRfiKp1ERcJL7qYgIpkNqOQ8IyQCX5Q8WasLxwltuGdwQLMfPWXDjv80cYv5Rh28+fA4/Mf+z+5/T4JTd0WLikTAKCwjAc9cPNWxmJzWaz/bs+ARw+WspiETJ4AAAAAElFTkSuQmCC","orcid":"","institution":"University of Tokyo","correspondingAuthor":true,"prefix":"","firstName":"Yueh-Chi","middleName":"","lastName":"Lin","suffix":""},{"id":483122832,"identity":"f87a36f7-ba73-433f-98c0-bc3297145fa8","order_by":1,"name":"Masahiro Watanabe","email":"","orcid":"https://orcid.org/0000-0001-6500-2101","institution":"University of Tokyo","correspondingAuthor":false,"prefix":"","firstName":"Masahiro","middleName":"","lastName":"Watanabe","suffix":""}],"badges":[],"createdAt":"2025-07-06 16:55:13","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7059131/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7059131/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":88563234,"identity":"d1970e3a-f62f-4b6c-bc11-f88c9d5821d6","added_by":"auto","created_at":"2025-08-07 18:40:49","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2006470,"visible":true,"origin":"","legend":"","description":"","filename":"NCLIMMainfinalYC.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7059131/v1_covered_63ac00d4-5146-47ae-a8d1-ba9f4551125a.pdf"},{"id":88562717,"identity":"b9f4f87a-e68c-4208-a553-d58d5f8a48b1","added_by":"auto","created_at":"2025-08-07 18:32:46","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":38770470,"visible":true,"origin":"","legend":"Supplementary Figures and Table","description":"","filename":"NCLIMSupplementaryfinalYC.docx","url":"https://assets-eu.researchsquare.com/files/rs-7059131/v1/b97435efc5b2edc3a3d24aa4.docx"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"North Atlantic influence reconciling model-observation discrepancy in the tropical Pacific warming pattern","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-7059131/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7059131/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Over the past four decades, zonal contrast in the tropical Pacific sea surface temperature (SST) has strengthened in observations but weakened in majority of climate model simulations. 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