Modulation of quasi-biennial oscillation on the relationship between ENSO and the South China Sea summer monsoon

Modulation of quasi-biennial oscillation on the relationship between ENSO and the South China Sea summer monsoon | 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 Modulation of quasi-biennial oscillation on the relationship between ENSO and the South China Sea summer monsoon Yiyang Hu, Maoqiu Jian, Si Gao This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7226797/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 In this study, the modulation of the equatorial stratospheric quasi-biennial oscillation (QBO) in winter on the impact of the El Niño–Southern Oscillation (ENSO) on the South China Sea summer monsoon intensity (SCSSMI) is investigated during 1952–2020. In the QBO westerly phase (WQBO), ENSO is closely correlated with the SCSSMI, while the relationship is weak in the QBO easterly phase (EQBO). The evolution of ENSO-related sea surface temperature (SST) exhibits distinctive features under different QBO phases. During winter to spring, WQBO suppresses deep convection over the Maritime Continent (MC) during El Niño events, but the suppression effect is weak during La Niña events, which results in the ENSO-related SST evolution in the Indo-Pacific Ocean similar to the canonical ENSO events and a close relationship between SST in the equatorial central and eastern Pacific in ENSO mature winter and the SCSSMI in ENSO decaying summer. While EQBO significantly enhances deep convection over the MC and causes anomalous tropical zonal circulation over the Indo-Pacific during winter to spring. Related to the anomalous zonal circulation over the Indo-Pacific during EQBO, anomalous vertical motion over the MC and anomalous surface wind in the Indo-Pacific modulate the ENSO-related SST evolution in the Indo-Pacific, inducing insignificant warm SST anomalies in the Indian Ocean during the El Niño decaying summer and significant cold SST anomalies in the Indo-Pacific during La Niña decaying summer. These abnormal SST patterns produce negligible influence on the SCSSMI, implying that ENSO exerts weak impact on the SCSSMI during EQBO. South China Sea summer monsoon QBO ENSO interannual variability Full Text 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. 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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-7226797","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":495460634,"identity":"9486a4d9-b4e5-4e66-9d78-436d20e1443c","order_by":0,"name":"Yiyang Hu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAw0lEQVRIiWNgGAWjYBACefnjBx8kGPyzY2NvIFKL4QyeZIMHBQeS+XkOEGvNDQYzyQcfDjDOnJFApA7G2Q3JBgkGd5gNbj7eeIOhxiaaoBZ2mYMgvzzjM7idVmzBcCwtt4GgLQ0JIFuYmQ1u55hJMDYcJqyF4UCCmQRQC+OGm2eI1XIDrOUw0Ps8RGox7DkDclgaMJCBfkkgxi/y7O0HH/74YwOMysMbb3yosSHCYUjAQCKBFOUQLaTqGAWjYBSMgpEBAImGRATYTbqCAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0009-0004-5144-1057","institution":"Sun Yat-Sen University","correspondingAuthor":true,"prefix":"","firstName":"Yiyang","middleName":"","lastName":"Hu","suffix":""},{"id":495460635,"identity":"1ea1bf6e-7ef1-45fe-b23f-5e6ea7cf0127","order_by":1,"name":"Maoqiu Jian","email":"","orcid":"https://orcid.org/0000-0003-1356-6102","institution":"Sun Yat-Sen University","correspondingAuthor":false,"prefix":"","firstName":"Maoqiu","middleName":"","lastName":"Jian","suffix":""},{"id":495460636,"identity":"e108d125-0a23-4133-819c-0d9f21c84b78","order_by":2,"name":"Si Gao","email":"","orcid":"","institution":"Sun Yat-Sen University","correspondingAuthor":false,"prefix":"","firstName":"Si","middleName":"","lastName":"Gao","suffix":""}],"badges":[],"createdAt":"2025-07-27 14:32:29","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7226797/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7226797/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":101207023,"identity":"806f7a2d-9d85-42f7-b068-3812a5f7ceb9","added_by":"auto","created_at":"2026-01-27 09:57:08","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2687985,"visible":true,"origin":"","legend":"","description":"","filename":"QBOENSOSCSSMImanuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7226797/v1_covered_fb715e22-bcb1-46c8-9b7f-ce716a062181.pdf"}],"financialInterests":"","formattedTitle":"Modulation of quasi-biennial oscillation on the relationship between ENSO and the South China Sea summer monsoon","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"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":"South China Sea summer monsoon, QBO, ENSO, interannual variability","lastPublishedDoi":"10.21203/rs.3.rs-7226797/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7226797/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIn this study, the modulation of the equatorial stratospheric quasi-biennial oscillation (QBO) in winter on the impact of the El Ni\u0026ntilde;o\u0026ndash;Southern Oscillation (ENSO) on the South China Sea summer monsoon intensity (SCSSMI) is investigated during 1952\u0026ndash;2020. In the QBO westerly phase (WQBO), ENSO is closely correlated with the SCSSMI, while the relationship is weak in the QBO easterly phase (EQBO). The evolution of ENSO-related sea surface temperature (SST) exhibits distinctive features under different QBO phases. During winter to spring, WQBO suppresses deep convection over the Maritime Continent (MC) during El Ni\u0026ntilde;o events, but the suppression effect is weak during La Ni\u0026ntilde;a events, which results in the ENSO-related SST evolution in the Indo-Pacific Ocean similar to the canonical ENSO events and a close relationship between SST in the equatorial central and eastern Pacific in ENSO mature winter and the SCSSMI in ENSO decaying summer. While EQBO significantly enhances deep convection over the MC and causes anomalous tropical zonal circulation over the Indo-Pacific during winter to spring. Related to the anomalous zonal circulation over the Indo-Pacific during EQBO, anomalous vertical motion over the MC and anomalous surface wind in the Indo-Pacific modulate the ENSO-related SST evolution in the Indo-Pacific, inducing insignificant warm SST anomalies in the Indian Ocean during the El Ni\u0026ntilde;o decaying summer and significant cold SST anomalies in the Indo-Pacific during La Ni\u0026ntilde;a decaying summer. These abnormal SST patterns produce negligible influence on the SCSSMI, implying that ENSO exerts weak impact on the SCSSMI during EQBO.\u003c/p\u003e","manuscriptTitle":"Modulation of quasi-biennial oscillation on the relationship between ENSO and the South China Sea summer monsoon","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-07 19:08:52","doi":"10.21203/rs.3.rs-7226797/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":"f33803fd-96f9-4618-8b60-bd42a75ee999","owner":[],"postedDate":"August 7th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-01-26T18:16:14+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-07 19:08:52","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7226797","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7226797","identity":"rs-7226797","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}