Time-Lagged Climate and Vegetation Feedbacks Intensify Seasonal CO2 Exchange in High Latitudes

Time-Lagged Climate and Vegetation Feedbacks Intensify Seasonal CO2 Exchange in High Latitudes | 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 Time-Lagged Climate and Vegetation Feedbacks Intensify Seasonal CO2 Exchange in High Latitudes Naixin Fan, Matthias Forkel, Wolfgang Buermann, Stephen Sitch, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8284277/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 amplitude of the atmospheric CO₂ seasonal cycle has risen sharply since the 1960s, especially across northern high latitudes, yet the mechanisms driving this amplification remain unresolved. Using a time-lag detection framework applied to four decades of CO₂ records, satellite observa-tions, and dynamic vegetation model simulations, we show that the intensifying seasonal cycle arises from a cascade of immediate and lagged ecosystem responses to climatic variability. Two transitional months—May and October, marking the onset and end of the growing season—dominate interannual variability and long-term trends in CO2 amplitude over northern ecosystems. October respiration and productivity exert the strongest influence via a two-year legacy pathway in which warm, productive autumns dry soils, delay refreezing, alter vegetation structure and ecosys-tem carbon storage, thereby conditioning the sensitivity of the subsequent spring carbon fluxes. Earlier snowmelt and higher May temperatures then translate the stored memory into enhanced ecosystem-atmosphere carbon exchange. Together, our findings reveal a coupled hydroclimate-cryosphere-vegetation feedback linking autumn legacies to spring responses, embedding multi-year memory into northern carbon–climate dynamics. Earth and environmental sciences/Biogeochemistry/Carbon cycle Earth and environmental sciences/Climate sciences/Biogeochemistry Full Text Additional Declarations There is NO Competing Interest. Supplementary Files FanCO2ampsupplementDecNature.pdf Time-Lagged Climate and Vegetation Feedbacks Intensify Seasonal CO2 Exchange in High Latitudes 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-8284277","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Physical Sciences - Article","associatedPublications":[],"authors":[{"id":575068368,"identity":"22e5e33c-a1f6-4024-9514-aed0f460cb0c","order_by":0,"name":"Naixin Fan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA2UlEQVRIie3PIQvCQBTA8SeDWQbWJ6J+hZMFEfZhdghaJhhNMhGWhl38EovGJwsWZfWCwXNg1qbNEw2m20XD/dLjeH+OB2BZf6kWQwjQAHCIYKoeyDBpxuCGBMwo+VCJp/ZNkn49T1BuARub9E4PFvAVOfIiNMkg5UvGD4B4Oma7lI34mlzfjzQJI7448wTmICZZDiznGXluS5sUMiaVYFdEZ8NEfH5BJiIwTaS6JUHsiRF73+Kv86pbivG1+UwC7IhheXvMgvZqv5SlLvnCn9mpXrcsy7IqvABnLVPc8kzyFwAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0001-7370-5843","institution":"TUD Dresden University of Technology","correspondingAuthor":true,"prefix":"","firstName":"Naixin","middleName":"","lastName":"Fan","suffix":""},{"id":575068369,"identity":"5e24477b-43b2-492f-8ba6-82720c30652c","order_by":1,"name":"Matthias Forkel","email":"","orcid":"https://orcid.org/0000-0003-0363-9697","institution":"TUD Dresden University of Technology","correspondingAuthor":false,"prefix":"","firstName":"Matthias","middleName":"","lastName":"Forkel","suffix":""},{"id":575068370,"identity":"a9f0680a-97e9-4e68-ad5e-0f21bbdf9420","order_by":2,"name":"Wolfgang Buermann","email":"","orcid":"","institution":"Institute of Geography, University of Augsburg","correspondingAuthor":false,"prefix":"","firstName":"Wolfgang","middleName":"","lastName":"Buermann","suffix":""},{"id":575068371,"identity":"ec2e62a8-0f19-4287-9fd8-6b94a7f37f7d","order_by":3,"name":"Stephen Sitch","email":"","orcid":"https://orcid.org/0000-0003-1821-8561","institution":"University of Exeter","correspondingAuthor":false,"prefix":"","firstName":"Stephen","middleName":"","lastName":"Sitch","suffix":""},{"id":575068372,"identity":"aae27cf2-00fc-4fe6-82c1-f2f2c3b5ac5f","order_by":4,"name":"Markus Drüke","email":"","orcid":"","institution":"Deutscher Wetterdienst (DWD), Hydrometeorology","correspondingAuthor":false,"prefix":"","firstName":"Markus","middleName":"","lastName":"Drüke","suffix":""},{"id":575068373,"identity":"5f4bda2c-3210-44a6-a402-745f698e712e","order_by":5,"name":"Christian Rödenbeck","email":"","orcid":"https://orcid.org/0000-0001-6011-6249","institution":"Max-Planck-Institute for Biogeochemistry","correspondingAuthor":false,"prefix":"","firstName":"Christian","middleName":"","lastName":"Rödenbeck","suffix":""},{"id":575068374,"identity":"f4a10751-d038-4bf1-a314-bfda3f99a065","order_by":6,"name":"Kirsten Thonicke","email":"","orcid":"https://orcid.org/0000-0001-5283-4937","institution":"Potsdam Institute for Climate Impact Research","correspondingAuthor":false,"prefix":"","firstName":"Kirsten","middleName":"","lastName":"Thonicke","suffix":""}],"badges":[],"createdAt":"2025-12-05 04:55:07","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8284277/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8284277/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":103773142,"identity":"dbe8924b-75bb-408f-970f-bb1c277a6bf4","added_by":"auto","created_at":"2026-03-02 17:41:01","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":909763,"visible":true,"origin":"","legend":"Article File","description":"","filename":"FanCO2ampmanuscriptDecNature.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8284277/v1_covered_bc9d5c05-a6f0-4127-884d-0c8579b48e4a.pdf"},{"id":100420459,"identity":"f4c32586-5f13-40cc-9a6e-6c1ab76b0564","added_by":"auto","created_at":"2026-01-16 13:28:42","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":7174978,"visible":true,"origin":"","legend":"Time-Lagged Climate and Vegetation Feedbacks Intensify Seasonal CO2 Exchange in High Latitudes","description":"","filename":"FanCO2ampsupplementDecNature.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8284277/v1/8f503e934998de4a401f4758.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Time-Lagged Climate and Vegetation Feedbacks Intensify Seasonal CO2 Exchange in High Latitudes","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-8284277/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8284277/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"The amplitude of the atmospheric CO₂ seasonal cycle has risen sharply since the 1960s, especially across northern high latitudes, yet the mechanisms driving this amplification remain unresolved. Using a time-lag detection framework applied to four decades of CO₂ records, satellite observa-tions, and dynamic vegetation model simulations, we show that the intensifying seasonal cycle arises from a cascade of immediate and lagged ecosystem responses to climatic variability. Two transitional months—May and October, marking the onset and end of the growing season—dominate interannual variability and long-term trends in CO2 amplitude over northern ecosystems. October respiration and productivity exert the strongest influence via a two-year legacy pathway in which warm, productive autumns dry soils, delay refreezing, alter vegetation structure and ecosys-tem carbon storage, thereby conditioning the sensitivity of the subsequent spring carbon fluxes. Earlier snowmelt and higher May temperatures then translate the stored memory into enhanced ecosystem-atmosphere carbon exchange. Together, our findings reveal a coupled hydroclimate-cryosphere-vegetation feedback linking autumn legacies to spring responses, embedding multi-year memory into northern carbon–climate dynamics.","manuscriptTitle":"Time-Lagged Climate and Vegetation Feedbacks Intensify Seasonal CO2 Exchange in High Latitudes","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-16 13:20:23","doi":"10.21203/rs.3.rs-8284277/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a6cff19e-ceb9-4a6e-8c58-eba72702bed0","owner":[],"postedDate":"January 16th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":61189982,"name":"Earth and environmental sciences/Biogeochemistry/Carbon cycle"},{"id":61189983,"name":"Earth and environmental sciences/Climate sciences/Biogeochemistry"}],"tags":[],"updatedAt":"2026-03-02T17:40:51+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-16 13:20:23","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8284277","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8284277","identity":"rs-8284277","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}