AMOC Strength, Salt-Advection Feedback, and Gyre Dynamics in Models and Reanalyses

AMOC Strength, Salt-Advection Feedback, and Gyre Dynamics in Models and Reanalyses | 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 AMOC Strength, Salt-Advection Feedback, and Gyre Dynamics in Models and Reanalyses Alessandro Raganato, Annalisa Bracco, Luke Van Roekel, Doroteaciro Iovino This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7926791/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 The Atlantic Meridional Overturning Circulation (AMOC) exerts a major influence on the global climate, yet its multi-scale variability and changes remain uncertain. Using four ocean reanalyses (GODAS, ORAS5, SODA, and GLORYS12) and forced ocean-sea ice (FOSI) simulations (E3SM-MPAS, CESM-POP, and CMCC-NEMO) at both coarse and mesoscale-permitting resolutions, we examine the relationships between AMOC strength, freshwater transport, salt–advection feedback, and sea surface height (SSH) as a proxy for subtropical gyre circulation. Eddy-permitting and eddy-resolving models and reanalysis generally simulate a stronger overturning, more realistic freshwater transport, and enhanced gyre circulation than coarse-resolution configurations. The salt–advection feedback is consistently negative across datasets, with statistically robust sensitivities in the North Atlantic and clear resolution dependence. In contrast, it is weak, noisy, and inconsistent across datasets in the South Atlantic, where wind-driven transport and eddy compensation can obscure the signal. SSH-derived gyre strength is linearly coupled with the AMOC strength in both the North and South Atlantic across both models and reanalyses with the exception of ORAS5 in the South. These results emphasize the close relationship between the strength of the gyre circulations and AMOC in ocean models, underscoring the importance of properly representing a quantity easily accessible through satellite observations such as SSH to better constrain the representation of the AMOC. Oceanography Climate Analysis and Modeling Full Text Additional Declarations The authors declare no competing interests. Supplementary Files SupplementaryMaterialpreprint.pdf 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. 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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-7926791","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":533609100,"identity":"13a8c89f-ac56-4652-817e-9e0b7ecb4f39","order_by":0,"name":"Alessandro Raganato","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9ElEQVRIiWNgGAWjYFAD/uYDYNoAiCWI0SDBIHEsgYEhgSQtDDkGxGnhn3348YufO+zq+BnOfH7x84eNvDkD88HbPPhMP5dmZtl7JllCsrl3m2VPQprhzga2ZGt8WhjOMJgZ8LYxSxgcOLvNgCfhcILBAR4zaXxa5M+wfzP821YP1JLzzPBPwn+gFv5veLUYnOExfszbdhikhfkxT8IBkC1seLUYnuEpY5ZtOy45c8YxM2aZtGTDDYfZjC3n4NEid4Z988e3bdX8/PzNjz++sbGTNzje/PDGG3zeZ2Bgk0BlMONXDlbyAZ0xCkbBKBgFowAFAAAGQU2Yo5e38AAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0009-0009-1325-5831","institution":"Georgia Institute of Technology","correspondingAuthor":true,"prefix":"","firstName":"Alessandro","middleName":"","lastName":"Raganato","suffix":""},{"id":533609101,"identity":"1b99ccfc-12f7-45c6-b4e1-60c16e708699","order_by":1,"name":"Annalisa Bracco","email":"","orcid":"","institution":"CMCC Foundation - 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