Frequent Floods in the Yangtze River Basin Linked to a shifted Indian Ocean Wave Regime

Frequent Floods in the Yangtze River Basin Linked to a shifted Indian Ocean Wave Regime | 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 Frequent Floods in the Yangtze River Basin Linked to a shifted Indian Ocean Wave Regime SungHyun Nam, Panini Dasgupta, Michael McPhaden, Dong-Jin Kang, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7086976/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 Six major summer monsoon floods occurred in the Yangtze Basin between 1992–2024, compared to only one during 1960–1991.This significant rise in hydroclimatic extremes is closely linked to enhanced variability at the quasi-biennial (QB) timescale. In this study, using sea surface height and thermocline depth from the ORAS5 reanalysis and EN4 observational analysis, we demonstrate that the increased QB variability in East Asian summer monsoon (EASM) rainfall over the Yangtze River Basin is strongly coupled with intensified QB-scale wave dynamics in the Indian Ocean. We provide evidence of fundamental changes in the characteristics of baroclinic waves in the tropical Indian Ocean over recent decades. We find that the mean phase speed of westward-propagating tropical Rossby waves has increased by 50–60%, along with their overall variance. These shifts are likely associated with changes in both oceanic circulation and large-scale atmospheric forcing. Our findings highlight that evolving Indian Ocean wave characteristics are a key contributor to the amplification of monsoon variability in QB timescales and associated hydrological extremes over East Asia. Focused scientific efforts are further needed to investigate the specific roles of possible drivers in altering wave properties and to assess their implications for EASM predictability and associated impacts. Earth and environmental sciences/Climate sciences/Ocean sciences/Physical oceanography Earth and environmental sciences/Ocean sciences/Physical oceanography Full Text Additional Declarations There is NO Competing Interest. Supplementary Files jgrjdmSupplementaryyangtzeriver20250710.pdf Supplementary Informations 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. 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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-7086976","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":486354365,"identity":"655db7a1-c0c3-4353-a600-ee84ada8aa6d","order_by":0,"name":"SungHyun 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