Processes and feedbacks for AMOC stability following freshwater-induced weakening

Processes and feedbacks for AMOC stability following freshwater-induced weakening | 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 Processes and feedbacks for AMOC stability following freshwater-induced weakening Laura Claire Jackson, Eduardo Alastrué de Asenjo, Katinka Bellomo, and 9 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8742476/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 5 You are reading this latest preprint version Abstract The stability of the Atlantic Meridional Overturning Circulation (AMOC) is a key uncertainty in climate projections. This study investigates the processes and feedbacks that determine whether the AMOC recovers or remains in a weak state following large freshwater perturbations, using coordinated hosing experiments from eight CMIP6-era climate models. The experiments apply a sustained surface freshwater input (hosing) over the North Atlantic and Arctic, weakening the AMOC. Results show that in half of the models, the AMOC does not recover within at least 100 years after hosingceases, indicating quasi-irreversible transitions to weak states. The key determinant of recovery is the state reached during hosing: models with the weakest AMOC and shallowest wintertime convection fail to recover. Analysis reveals that continued surface heat loss and dense water formation, particularly in the Greenland-Iceland-Norwegian (GIN) Seas, are essential for AMOC recovery. In models where these processes persist, the AMOC is maintained; where they cease, the AMOC remains weak. Feedbacks involving ocean heat and salt transport, surface fluxes, and sea ice extent are examined. In some models there is an increased advection of heat and salt into the GIN Seas, supporting deep convection and water mass transformation, and leading to a recovery of the AMOC. Other models show reduced advection of heat and salt, suppressing convection and preventing the AMOC recovery. These findings suggest that under strong freshwater forcing, some climate models can enter long-lasting weak AMOC states, with important implications for future climate risk. AMOC stability tipping points ocean Full Text Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Major Revision 13 Mar, 2026 Reviewers agreed at journal 10 Feb, 2026 Reviewers invited by journal 10 Feb, 2026 Editor assigned by journal 08 Feb, 2026 First submitted to journal 30 Jan, 2026 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-8742476","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":588941684,"identity":"97ebdf6a-c7c7-47e4-86d6-7874cc4f96d0","order_by":0,"name":"Laura Claire 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Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"AMOC, stability, tipping points, ocean","lastPublishedDoi":"10.21203/rs.3.rs-8742476/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8742476/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"The stability of the Atlantic Meridional Overturning Circulation (AMOC) is a key uncertainty in climate projections. This study investigates the processes and feedbacks that determine whether the AMOC recovers or remains in a weak state\nfollowing large freshwater perturbations, using coordinated hosing experiments from eight CMIP6-era climate models.\n\nThe experiments apply a sustained surface freshwater input (hosing) over the North Atlantic and Arctic, weakening the AMOC. Results show that in half of the models, the AMOC does not recover within at least 100 years after hosingceases, indicating quasi-irreversible transitions to weak states. The key determinant of recovery is the state reached during hosing: models with the weakest AMOC and shallowest wintertime convection fail to recover. Analysis reveals that continued surface heat loss and dense water formation, particularly in the Greenland-Iceland-Norwegian (GIN) Seas, are essential for AMOC recovery. In models where these processes persist, the AMOC is maintained; where they cease, the AMOC remains weak.\n\nFeedbacks involving ocean heat and salt transport, surface fluxes, and sea ice extent are examined. In some models there is an increased advection of heat and salt into the GIN Seas, supporting deep convection and water mass transformation, and leading to a recovery of the AMOC. Other models show reduced advection of heat and salt, suppressing convection and preventing the\nAMOC recovery. These findings suggest that under strong freshwater forcing, some climate models can enter long-lasting weak AMOC states, with important implications for future climate risk.","manuscriptTitle":"Processes and feedbacks for AMOC stability following freshwater-induced weakening","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-13 06:06:37","doi":"10.21203/rs.3.rs-8742476/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major Revision","date":"2026-03-13T04:44:42+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2026-02-10T11:59:20+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-10T11:49:46+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-09T04:24:57+00:00","index":"","fulltext":""},{"type":"submitted","content":"Climate Dynamics","date":"2026-01-30T09:50:07+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"climate-dynamics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cldy","sideBox":"Learn more about [Climate Dynamics](https://www.springer.com/journal/382)","snPcode":"382","submissionUrl":"https://submission.nature.com/new-submission/382/3","title":"Climate Dynamics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"a28004a6-4f43-40c1-9757-f6f66ff571fe","owner":[],"postedDate":"February 13th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[],"tags":[],"updatedAt":"2026-03-13T08:45:32+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-13 06:06:37","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8742476","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8742476","identity":"rs-8742476","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}