Dampening of the precipitation response to aerosol pollution from turbulence in cumulus clouds

Dampening of the precipitation response to aerosol pollution from turbulence in cumulus clouds | 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 Physical Sciences - Article Dampening of the precipitation response to aerosol pollution from turbulence in cumulus clouds Kamal Kant Chandrakar, Hugh Morrison This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6590441/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 The susceptibility of rain formation to aerosol emissions is a key aspect of aerosol-cloud-precipitation interactions. Using aircraft observations and a detailed cloud model with a state-of-the-art particle-based representation of microphysics, it is shown that the enhancement of drop collision-coalescence from turbulent flow in clouds -- which is neglected in current climate models -- leads to earlier onset of rain in warm cumulus clouds and significantly dampens the precipitation susceptibility to aerosol loading. Enhanced drop coalescence from turbulence substantially increases the production of embryonic drizzle drops just above cloud base, which in turn act as seeds that accelerate rain drop growth at mid and upper cloud levels even in highly polluted conditions. In contrast, pollution aerosols strongly inhibit rainfall when the commonly assumed gravitational-only collision kernel is used in the model and turbulent coalescence is neglected. There is also a large impact of turbulent drop coalescence on the mean cloud water amount and optical depth. Overall, turbulence-enhanced drop coalescence strongly influences the response of warm cumulus clouds and precipitation to aerosol loading, suggesting that the effects of turbulent coalescence should be included in climate model representations of aerosol-cloud-precipitation interactions and aerosol indirect radiative forcing. Earth and environmental sciences/Climate sciences/Atmospheric science Earth and environmental sciences/Planetary science/Atmospheric dynamics Precipitation susceptibility Aerosol indirect effects Warm rain Cloud-turbulence interactions Full Text Additional Declarations There is NO Competing Interest. 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-6590441","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Physical Sciences - Article","associatedPublications":[],"authors":[{"id":455628062,"identity":"f8baecaa-62a4-4e21-b46d-063e617b5a88","order_by":0,"name":"Kamal Kant Chandrakar","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAwElEQVRIiWNgGAWjYBACCR4GNiDFzMAPFWBsIFqLZAPJWgwOEKtFsufwswc/d1jnG99Ifvi5gsFGdsMBAlqkedvMDXvPpFtuu5FmLHmGIc2YoBY5fh42Cd62wwZmN3JA/jmcSJQWyb9ALcYzcph/NjD8J6xFmreHTRpki4FEDhvQlgOEtUj2HDOTlm1LN5A488zMssEg2XgmIS0SZ5KfSb5tszbgb09+fLOhwk62j5AWNGBAmvJRMApGwSgYBTgAAITKPV9SQfTMAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0003-2970-3458","institution":"NSF National Center for Atmospheric Research (NCAR)","correspondingAuthor":true,"prefix":"","firstName":"Kamal","middleName":"Kant","lastName":"Chandrakar","suffix":""},{"id":455628063,"identity":"79b13a18-fa33-4ac2-87b3-202f3eff8944","order_by":1,"name":"Hugh Morrison","email":"","orcid":"","institution":"NCAR","correspondingAuthor":false,"prefix":"","firstName":"Hugh","middleName":"","lastName":"Morrison","suffix":""}],"badges":[],"createdAt":"2025-05-04 23:40:06","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6590441/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6590441/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":83531547,"identity":"de9be6b1-e6dd-437a-8c51-7135e4c1bcd7","added_by":"auto","created_at":"2025-05-28 05:08:58","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":743816,"visible":true,"origin":"","legend":"Article File","description":"","filename":"ChandrakarNatureManuscript2025.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6590441/v1_covered_92db08b2-f5c1-4413-ab76-09637dfbb1b1.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Dampening of the precipitation response to aerosol pollution from turbulence in cumulus clouds","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Precipitation susceptibility, Aerosol indirect effects, Warm rain, Cloud-turbulence interactions","lastPublishedDoi":"10.21203/rs.3.rs-6590441/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6590441/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"The susceptibility of rain formation to aerosol emissions is a key aspect of aerosol-cloud-precipitation interactions. Using aircraft observations and a detailed cloud model with a state-of-the-art particle-based representation of microphysics, it is shown that the enhancement of drop collision-coalescence from turbulent flow in clouds -- which is neglected in current climate models -- leads to earlier onset of rain in warm cumulus clouds and significantly dampens the precipitation susceptibility to aerosol loading. Enhanced drop coalescence from turbulence substantially increases the production of embryonic drizzle drops just above cloud base, which in turn act as seeds that accelerate rain drop growth at mid and upper cloud levels even in highly polluted conditions. In contrast, pollution aerosols strongly inhibit rainfall when the commonly assumed gravitational-only collision kernel is used in the model and turbulent coalescence is neglected. There is also a large impact of turbulent drop coalescence on the mean cloud water amount and optical depth. Overall, turbulence-enhanced drop coalescence strongly influences the response of warm cumulus clouds and precipitation to aerosol loading, suggesting that the effects of turbulent coalescence should be included in climate model representations of aerosol-cloud-precipitation interactions and aerosol indirect radiative forcing.","manuscriptTitle":"Dampening of the precipitation response to aerosol pollution from turbulence in cumulus clouds","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-28 05:08:39","doi":"10.21203/rs.3.rs-6590441/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"nature-communications","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"NCOMMS","sideBox":"Learn more about [Nature Communications](http://www.nature.com/ncomms/)","snPcode":"","submissionUrl":"https://mts-ncomms.nature.com/","title":"Nature Communications","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature Communications","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"8cf648e9-132b-4532-b353-49267d26e00d","owner":[],"postedDate":"May 28th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":48432008,"name":"Earth and environmental sciences/Climate sciences/Atmospheric science"},{"id":48432009,"name":"Earth and environmental sciences/Planetary science/Atmospheric dynamics"}],"tags":[],"updatedAt":"2025-05-28T05:08:39+00:00","versionOfRecord":[],"versionCreatedAt":"2025-05-28 05:08:39","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6590441","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6590441","identity":"rs-6590441","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}