Heating the land cools the eastern and equatorial Pacific

Heating the land cools the eastern and equatorial Pacific | 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 Heating the land cools the eastern and equatorial Pacific Moritz Günther, Sarah Kang, Yohai Kaspi This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7189653/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The unresolved recent multidecadal cooling of the eastern Pacific and its uncertain future remain key puzzles in climate dynamics. We propose the land-sea heating contrast as a potential driver of this phenomenon. To test this, we deliberately amplify the land-sea contrast by quadrupling CO 2 only over land in a global coupled climate model. We show that this causes a pronounced transient cooling of the eastern and equatorial Pacific. A transient 1%-per-year CO 2 increase over land produces similar cooling on decadal time scales, suggesting relevance to the observed Eastern Pacific cooling. Targeted simulations with locally increased CO 2 concentrations over different land regions reveal three drivers of this cooling: a northward ITCZ shift, a westward convection shift over the Western Pacific, and strengthened Subtropical Highs from Rossby waves. These insights question the commonly employed ocean dynamical thermostat mechanism's importance for transient cooling, and contribute to understanding and predicting Pacific temperature patterns. Earth and environmental sciences/Climate sciences/Climate change/Climate and Earth system modelling Earth and environmental sciences/Climate sciences/Atmospheric science/Atmospheric dynamics Full Text Additional Declarations There is NO Competing Interest. Supplementary Files v5submissionsupplement.pdf Supplementary Information Cite Share Download PDF Status: Posted 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-7189653","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":492064781,"identity":"ccd502f9-56d7-42ac-acb3-fd2c5e56fa36","order_by":0,"name":"Moritz Günther","email":"data:image/png;base64,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","orcid":"https://orcid.org/0000-0003-2719-4821","institution":"Max Planck Institute for Meteorology","correspondingAuthor":true,"prefix":"","firstName":"Moritz","middleName":"","lastName":"Günther","suffix":""},{"id":492064782,"identity":"57e0a565-d8c6-4d95-92c6-3661e978f260","order_by":1,"name":"Sarah Kang","email":"","orcid":"https://orcid.org/0000-0003-4635-275X","institution":"Max Planck Institute for Meteorology","correspondingAuthor":false,"prefix":"","firstName":"Sarah","middleName":"","lastName":"Kang","suffix":""},{"id":492064783,"identity":"a095f166-e94e-4e3d-8cf3-d3624771ea56","order_by":2,"name":"Yohai Kaspi","email":"","orcid":"https://orcid.org/0000-0003-4089-0020","institution":"Weizmann Institute of Science","correspondingAuthor":false,"prefix":"","firstName":"Yohai","middleName":"","lastName":"Kaspi","suffix":""}],"badges":[],"createdAt":"2025-07-22 18:00:13","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-7189653/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7189653/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":88505215,"identity":"5770cb1f-ceb2-4bc3-b335-abf9aa9321ae","added_by":"auto","created_at":"2025-08-07 07:21:12","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4701561,"visible":true,"origin":"","legend":"Article File","description":"","filename":"v5submission.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7189653/v1_covered_2aecfe5e-7c19-4afb-9b69-355f627ed1fb.pdf"},{"id":87788178,"identity":"22ce1adf-3029-46bd-8b4d-ce7cc220d684","added_by":"auto","created_at":"2025-07-29 04:51:20","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":12935532,"visible":true,"origin":"","legend":"Supplementary Information","description":"","filename":"v5submissionsupplement.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7189653/v1/62034add67dc369e11aa671b.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Heating the land cools the eastern and equatorial Pacific","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":true,"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-7189653/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7189653/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"The unresolved recent multidecadal cooling of the eastern Pacific and its uncertain future remain key puzzles in climate dynamics. 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