Tropical Precipitation Response to Anthropogenic Climate Change in Recent Decades

Tropical Precipitation Response to Anthropogenic Climate Change in Recent Decades | 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 Tropical Precipitation Response to Anthropogenic Climate Change in Recent Decades Ligin Joseph, Pascal Terray, Puthiya Veettil Sooraj Kallikkal, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7538088/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 This study investigates tropical precipitation responses to anthropogenic climate change during 1979-2024 using ERA5 reanalysis, CMIP6 simulations, and targeted sensitivity experiments. While future projections often assume the direct effect of CO₂ forcing, “Wet Get Wetter” or “Warm Get Wetter” frameworks, their validity for explaining recent observed rainfall trends remains uncertain. Clausius-Clapeyron scaling and a moisture budget analysis indicate that dynamic processes dominate recent tropical rainfall responses. Observations reveal a northward precipitation shift with wetting in the western and north equatorial Pacific, northern Indian region, and drying south of the equator in the Pacific and in South America. These trends coincide with a La Niña-like SST pattern, strengthened Walker circulation, Southern Ocean cooling, enhanced land-sea and inter-hemispheric thermal gradients, and intensification of the Indo-Pacific warm pool. CMIP6 models largely miss the first three features, projecting El Niño–like SST trends, but capture thermal gradients and Indo-Pacific warm pool intensification. Regression analysis shows that amplifying land-sea and inter-hemispheric thermal contrasts, and Indo-Pacific warm pool intensification, reproduces very well the observed circulation and rainfall changes. However, coupled sensitivity experiments highlight land warming as an active driver of tropical hydroclimate changes, challenging ocean-centric assumptions in current climate models. Earth and environmental sciences/Climate sciences/Climate change/Attribution Earth and environmental sciences/Climate sciences/Climate change/Climate and Earth system modelling Precipitation Land-Sea Thermal Gradient Walker Circulation ENSO Full Text Additional Declarations There is NO Competing Interest. Supplementary Files NatureSupplementtoTropicalPrecipitationResponsetoAnthropogenicClimateChangeinRecentDecades.pdf Supplement for ’Tropical Precipitation Response to Anthropogenic Climate Change in Recent Decades’ 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-7538088","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":518417346,"identity":"47e2e3c6-12be-4b37-8aaa-a22622426e63","order_by":0,"name":"Ligin 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