Long-Term Trends in Subsurface Flows of Solar Cycle 23 to 25

Long-Term Trends in Subsurface Flows of Solar Cycle 23 to 25 | 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Research Article Long-Term Trends in Subsurface Flows of Solar Cycle 23 to 25 Rudolf Komm This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4824013/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 25 Oct, 2024 Read the published version in Solar Physics → Version 1 posted 7 You are reading this latest preprint version Abstract We study the long-term variation of the zonal and meridional flows from Solar Cycle 23 to 25 derived with ring-diagram analysis applied to Global Oscillation Network Group (GONG) and Helioseismic and Magnetic Imager (HMI) Dopplergrams. We focus mainly on the subsurface flows averaged over depths from 2.0 Mm to 11.6 Mm since their long-term variations are sufficiently similar. First, we examine their temporal variations for systematic artifacts. We find that the GONG-derived zonal flows increase almost linearly with time until about 2020, which we correct with a linear regression. Then, we determine the average differences between the GONG- and HMI derived flows. The average offset is 0.15 ± 0.53 m s−1 for the zonal flow and 0.65 ± 0.08 m s−1 for the meridional flow within ±30.0◦ latitude. The average difference of the meridional flow is nearly constant with latitude in this range, while that of the zonal flow varies similar to that of the magnetic activity. At latitudes of 45.0◦ and higher, the differences increase and are larger than those at lower latitudes, which is most likely due to geometric foreshortening. Finally, we combine the GONG- and HMI-derived flows and find, as expected, that the solar-cycle variation is the dominant long-term variation. At each latitude within ±30.0◦, the meridional-flow pattern appears ahead of the zonal-flow pattern by an average lag of 0.926±0.126 years. The equatorward and poleward branches of the solar-cycle variation occur at 52.5◦ with the poleward branches present near 60.0◦ and the equatorward ones at lower latitudes. The zonal flows at 52.5◦ and 60.0◦ show an additional trend and decrease by 2.9±0.3 m s−1 over 11 years. This decrease might nevertheless be related to the solar cycle and imply that the flow amplitudes are anti-correlated with the strength of the associated solar cycle. Helioseismology observations Velocity fields interior Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 25 Oct, 2024 Read the published version in Solar Physics → Version 1 posted Editorial decision: Revision requested 23 Aug, 2024 Reviews received at journal 23 Aug, 2024 Reviewers agreed at journal 02 Aug, 2024 Reviewers invited by journal 31 Jul, 2024 Editor assigned by journal 30 Jul, 2024 Submission checks completed at journal 30 Jul, 2024 First submitted to journal 29 Jul, 2024 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. 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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-4824013","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":344012434,"identity":"5fe1ca0d-ccf0-44b7-a623-23195b744afc","order_by":0,"name":"Rudolf Komm","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAmklEQVRIiWNgGAWjYDACHhBRAWFLkKDlDMlaGNtI0WLec/joppvz7tjzMzAfvM1DjBaZs21pt3O3PUuc2cCWbE2UFgl+HjOglsMJBgd4zKRJ0DLnsL3BAf5vRGrh7QFqaTjMuOEADxuRWniOpd3OOXY4cWYzm7HlHOK0JB+7nVNz2J6fvfnhjTfEaEEAZtKUj4JRMApGwSjABwCLxS3M+XrEJAAAAABJRU5ErkJggg==","orcid":"","institution":"National Solar Observatory","correspondingAuthor":true,"prefix":"","firstName":"Rudolf","middleName":"","lastName":"Komm","suffix":""}],"badges":[],"createdAt":"2024-07-29 18:51:26","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4824013/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4824013/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s11207-024-02397-6","type":"published","date":"2024-10-25T15:57:49+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":67681968,"identity":"1c271b34-3265-44d0-b999-7ea691b0b10d","added_by":"auto","created_at":"2024-10-28 16:11:53","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":8462143,"visible":true,"origin":"","legend":"","description":"","filename":"msrk2024.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4824013/v1_covered_ceb4598d-7fa6-410e-b819-2846ce4750ab.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Long-Term Trends in Subsurface Flows of Solar Cycle 23 to 25","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"solar-physics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sola","sideBox":"Learn more about [Solar Physics](http://link.springer.com/journal/11207)","snPcode":"11207","submissionUrl":"https://submission.nature.com/new-submission/11207/3","title":"Solar Physics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Helioseismology, observations, Velocity fields, interior","lastPublishedDoi":"10.21203/rs.3.rs-4824013/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4824013/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eWe study the long-term variation of the zonal and meridional flows from Solar Cycle 23 to 25 derived with ring-diagram analysis applied to Global Oscillation Network Group (GONG) and Helioseismic and Magnetic Imager (HMI) Dopplergrams. 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