Precession-forced asymmetric continental heating shapes ENSO variability

Precession-forced asymmetric continental heating shapes ENSO variability | 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 Precession-forced asymmetric continental heating shapes ENSO variability Yufei Liu, Hu Yang, Haowen Dang, Gerrit Lohmann, Tao Lian, Zhengyao Lu, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7865695/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 Geologic and modelling evidence reveals that the ENSO is strongly affected by the precession of the Earth’s rotation axis, yet the mechanisms remain unclear due to interactions among multiple forcings. Using high-resolution model simulations reconstructing the ENSO activity across a full precessional cycle, we find that ENSO is strongest during austral summer perihelion, as today. This behavior arises from asymmetric continental heating: austral summer perihelion introduces strong warming on Australia, east of the Indo-Pacific ITCZ. Because deep convection favors the warmest areas, this causes the ITCZ and the Warm Pool to shift eastwards. As a result, the Pacific’s east-west thermal contrast is reduced, lowering the threshold for oscillations of convection and amplifying ENSO activity. In contrast, boreal summer perihelion warms Afro-Eurasia, shifts the ITCZ westward and weakens ENSO. Proxy records across the Indo-Pacific support this changes in climate state. Understanding asymmetric continental heating helps us link astronomical modulation to ENSO behavior and improve long-term predictions of tropical climate change. Climatology Full Text Additional Declarations The authors declare no competing interests. Supplementary Files SI.pdf Supporting Information for ”Precession-forced asymmetric continental heating shapes ENSO variability” 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-7865695","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":530023001,"identity":"69b75b0b-c4f2-4b90-9420-d203b56fabfb","order_by":0,"name":"Yufei Liu","email":"","orcid":"https://orcid.org/0009-0008-8151-3815","institution":"Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai)","correspondingAuthor":false,"prefix":"","firstName":"Yufei","middleName":"","lastName":"Liu","suffix":""},{"id":530023588,"identity":"1064e421-37c1-4d2e-8381-0dd4c74a80fa","order_by":1,"name":"Hu Yang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3ElEQVRIiWNgGAWjYJACZgYGGwYGdjDjAAMbkVrSwCRJWg4jtBAEBsfPHn5d2HbeXreZgflzYdsdeT4G5mcP8Go5k5dmPbPtduI2oEXGM9ueGbYxsJkb4NVyIMfMmLftdoLZYf4PybxthxnbGHjYJPBqOf8GpOWcvRnQlsNALfaEtdzIMX7M23aAEegwxmaglkSCWiRvvDFj5jmXDPILM5BxOLmNmc0Mrxa+8znGn3nK7OzNjjcwAxmHbee3Nz/Dq0UBGHdoCpjxqQcC+QYG5g8E1IyCUTAKRsFIBwASvETLB8dJMwAAAABJRU5ErkJggg==","orcid":"","institution":"Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai)","correspondingAuthor":true,"prefix":"","firstName":"Hu","middleName":"","lastName":"Yang","suffix":""},{"id":530023589,"identity":"a328670a-5b07-48a1-a1fc-8dc4c678b717","order_by":2,"name":"Haowen Dang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Haowen","middleName":"","lastName":"Dang","suffix":""},{"id":530023590,"identity":"aca2f5bc-898a-4a16-826e-63978538ff37","order_by":3,"name":"Gerrit Lohmann","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Gerrit","middleName":"","lastName":"Lohmann","suffix":""},{"id":530023591,"identity":"1d621cd9-56f6-4f49-8258-7d9417d906fb","order_by":4,"name":"Tao Lian","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Tao","middleName":"","lastName":"Lian","suffix":""},{"id":530023592,"identity":"10256058-a1ad-4548-991a-9908dd4dd0a3","order_by":5,"name":"Zhengyao Lu","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Zhengyao","middleName":"","lastName":"Lu","suffix":""},{"id":530023593,"identity":"25e9761a-ad51-442b-8fe5-48eb9f8b4e80","order_by":6,"name":"Xiaoxu Shi","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Xiaoxu","middleName":"","lastName":"Shi","suffix":""},{"id":530023594,"identity":"17fb0037-0559-4caf-ac1f-909fdd6e4b55","order_by":7,"name":"Jiping Liu","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Jiping","middleName":"","lastName":"Liu","suffix":""},{"id":530023595,"identity":"17ec0e8b-aec2-4bb1-a385-485b3b26ea8b","order_by":8,"name":"Hang Wang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Hang","middleName":"","lastName":"Wang","suffix":""},{"id":530023596,"identity":"943239bd-f7fd-455b-956d-4fb7cc4a6cf1","order_by":9,"name":"Feng Jiang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Feng","middleName":"","lastName":"Jiang","suffix":""},{"id":530023597,"identity":"7bfe7a01-1840-4ac0-8cb3-7fa24bca1eaf","order_by":10,"name":"Xinyue Deng","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Xinyue","middleName":"","lastName":"Deng","suffix":""},{"id":530023598,"identity":"d56bc980-8da2-4fb6-96be-4f0906493979","order_by":11,"name":"Xiaoming Hu","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Xiaoming","middleName":"","lastName":"Hu","suffix":""},{"id":530023599,"identity":"34351eca-5ef1-4fdd-abd0-7872884ef316","order_by":12,"name":"Dake Chen","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Dake","middleName":"","lastName":"Chen","suffix":""}],"badges":[],"createdAt":"2025-10-15 08:29:48","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-7865695/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7865695/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":93668383,"identity":"9d8b3de3-7d57-46fc-ac6e-97a68d017adf","added_by":"auto","created_at":"2025-10-16 09:29:37","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4678777,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7865695/v1_covered_06261119-bf17-486a-93c5-e09b119f61f9.pdf"},{"id":93667174,"identity":"247d77b4-eb6b-4b2c-a573-06e722f5ef68","added_by":"auto","created_at":"2025-10-16 09:21:27","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":6864920,"visible":true,"origin":"","legend":"\u003cp\u003eSupporting Information for ”Precession-forced asymmetric continental heating shapes ENSO variability”\u003c/p\u003e","description":"","filename":"SI.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7865695/v1/d8a68ce1c88956a1cad5fd66.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003ePrecession-forced asymmetric continental heating shapes ENSO variability\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai)","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-7865695/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7865695/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u0026nbsp;Geologic and modelling evidence reveals that the ENSO is strongly affected by the precession of the Earth’s rotation axis, yet the mechanisms remain unclear due to interactions among multiple forcings. Using high-resolution model simulations reconstructing the ENSO activity across a full precessional cycle, we find that ENSO is strongest during austral summer perihelion, as today. This behavior arises from asymmetric continental heating: austral summer perihelion introduces strong warming on Australia, east of the Indo-Pacific ITCZ. Because deep convection favors the warmest areas, this causes the ITCZ and the Warm Pool to shift eastwards. As a result, the Pacific’s east-west thermal contrast is reduced, lowering the threshold for oscillations of convection and amplifying ENSO activity. In contrast, boreal summer perihelion warms Afro-Eurasia, shifts the ITCZ westward and weakens ENSO. Proxy records across the Indo-Pacific support this changes in climate state. Understanding asymmetric continental heating helps us link astronomical modulation to ENSO behavior and improve long-term predictions of tropical climate change.\u003c/p\u003e","manuscriptTitle":"Precession-forced asymmetric continental heating shapes ENSO variability","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-16 09:21:22","doi":"10.21203/rs.3.rs-7865695/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","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}}],"origin":"","ownerIdentity":"f54139ed-2263-4ed8-82c2-fb4153902c63","owner":[],"postedDate":"October 16th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":56342133,"name":"Climatology"}],"tags":[],"updatedAt":"2025-10-16T09:21:22+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-16 09:21:22","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7865695","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7865695","identity":"rs-7865695","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}