Time Dependence of Solar Meridional Circulation

Time Dependence of Solar Meridional Circulation | 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 Time Dependence of Solar Meridional Circulation Roger Ulrich, Tham Tran, John E. Boyden This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6307262/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 A recent re-analysis of the digital archive record of Magnetogram and Dopplergram observations of the synoptic program at the 150-foot solar tower telescope at the Mt. Wilson Observatory (MWO) has shown that the processes known as meridional circulation and torsional oscillations are closely related (Ulrich, Tran, and Boyden 2023). The meridional circulation velocity is along lines of constant heliographic longitudes while the torsional oscillations are changes in the rotation rate. Previously an extension of the meridional circulation analysis of Ulrich (2010) revealed that the polar rotation slowdown periods of the torsional oscillations also coincide with the polar meridional circulation flow being toward the equator instead of the usual toward the pole pattern. We interpret these two polar velocity patterns as indicating that the material flow during the solar minimum periods has an upwelling that pushes matter toward the equator. It is generally believed that the polar region magnetic fields interact with the meridional flow in the following sequence: a) at or before sunspot minimum the meridional flow brings additional magnetic flux of the same polar sign to the pole increasing the polar field strength; b) after solar minimum the new cycle field reverses and opposes the polar field, reversing it. The polar upwelling is not part of this sequence and our observations could indicate the need for modification of the models. This paper provides details about the time dependence of the solar surface Meridional Circulation. dynamo Solar photosphere Solar meridional circulation Solar rotation Full Text Additional Declarations No competing interests reported. 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. 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-6307262","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":441889553,"identity":"e6968560-1e82-491f-a9b7-70cfccf5e592","order_by":0,"name":"Roger Ulrich","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA2UlEQVRIie3LsQqCQBzH8f9xcC5XrkaRr3AiBFHZqxQHPUKzINzmGwS+gmPjiaBL2Bq46N7QFLiVFUFDh20N9x1+8If/B0Cn+8cMAIn8+fsetWMpCX6QDQB53rQTAeSnPxCW9mrZ7I+2HYV1hYRHTR8nJVUSgyXhoXTizHAZEpxakvCZmhBIkShRTAixkJAUJJ0MO5BiGYkXsaV57ULk2s9ehElKlGRwJ0koOI+zDWarglMnJe50pyD9XOBLI7xFFGSoumy98TgP6tNZQT5btYM7v+t0Op3uWzc1y0UmS7zPuQAAAABJRU5ErkJggg==","orcid":"","institution":"University of California, Los Angeles","correspondingAuthor":true,"prefix":"","firstName":"Roger","middleName":"","lastName":"Ulrich","suffix":""},{"id":441889554,"identity":"866b9ec2-19d6-4ebe-976c-0bddf011f811","order_by":1,"name":"Tham Tran","email":"","orcid":"","institution":"University of California, Los Angeles","correspondingAuthor":false,"prefix":"","firstName":"Tham","middleName":"","lastName":"Tran","suffix":""},{"id":441889555,"identity":"6f686972-1624-4fcb-874e-e30ef11fe687","order_by":2,"name":"John E. 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