Giant icebergs increase mixing and stratification in upper-ocean layers

Giant icebergs increase mixing and stratification in upper-ocean layers | 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 Giant icebergs increase mixing and stratification in upper-ocean layers Natasha Lucas, James Brearley, Katherine Hendry, Theo Spira, Anne Braakmann-Folgmann, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4425629/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 04 Apr, 2025 Read the published version in Nature Geoscience → Version 1 posted You are reading this latest preprint version Abstract Ice sheet mass loss is one of the clearest manifestations of climate change, with Antarctica discharging mass into the ocean via the melting of glacial ice or through calving. This calving produces icebergs which can modify ocean water properties, often at great distances from source. This affects upper ocean physics and primary productivity, with implications for atmospheric carbon drawdown. Detailed understanding of iceberg modification of ocean waters has hitherto been hindered by a lack of proximal measurements. Here, unique measurements of a giant iceberg from an underwater glider quantifies meltwater effects on the physical and biological processes in the upper layers of the Southern Ocean, a region disproportionately important for global heat and carbon sequestration. Iceberg basal melting erodes seasonally-produced Winter Water (WW) layer stratification, normally forming a strong potential energy barrier to vertical exchange of surface and deep waters, whilst freshwater runoff increases and shoals near-surface stratification. Nutrient-rich deeper waters, incorporating terrigenous loaded meltwater, are ventilated to below this stratification maxima, providing a potential mechanism for alleviating critical biological limiting components. Regional historical hydrographic data demonstrates similar stratification changes during the passage of another large iceberg, suggesting that they may be an important pathway of aseasonal WW modification. Physical sciences/Physics/Fluid dynamics Earth and environmental sciences/Ocean sciences/Physical oceanography Earth and environmental sciences/Climate sciences/Ocean sciences/Physical oceanography Earth and environmental sciences/Climate sciences/Climate change/Projection and prediction Earth and environmental sciences/Biogeochemistry/Carbon cycle iceberg glider ocean mixing winter water melting cryosphere Southern Ocean Antarctica Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Published Journal Publication published 04 Apr, 2025 Read the published version in Nature Geoscience → 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-4425629","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Physical Sciences - Article","associatedPublications":[],"authors":[{"id":307847473,"identity":"d74645a7-7c3a-4e2a-8446-c2aa3d8504ac","order_by":0,"name":"Natasha Lucas","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAsElEQVRIiWNgGAWjYNCCigMwVgKxWs6QrIWxjRQt5uyHH378Oe+OvHwD88MPjG1phLVY9qQZS/Nue2a44QCbsQRjWw5hLQYHchikGbcdZtzAwGAGdGEFEVrOv2H++XPOYfv5DezfiNRyI4dNgrfhcGLDAR6QLcQ47MYzM2ueY8+SNxzmKZZIOEeE9w3OJz+++aPmju389vaNHz6UJRPWggDMDCTE/SgYBaNgFIwC/AAA8+g6XfqD5KoAAAAASUVORK5CYII=","orcid":"https://orcid.org/0000-0002-1691-913X","institution":"British Antarctic Survey","correspondingAuthor":true,"prefix":"","firstName":"Natasha","middleName":"","lastName":"Lucas","suffix":""},{"id":307847474,"identity":"112c2d45-6758-4337-8b8b-bab03c0faccb","order_by":1,"name":"James Brearley","email":"","orcid":"","institution":"British Antarctic Survey","correspondingAuthor":false,"prefix":"","firstName":"James","middleName":"","lastName":"Brearley","suffix":""},{"id":307847475,"identity":"e3f83ab1-dc58-4f41-8b5e-10d47a9bfc32","order_by":2,"name":"Katherine Hendry","email":"","orcid":"","institution":"BAS","correspondingAuthor":false,"prefix":"","firstName":"Katherine","middleName":"","lastName":"Hendry","suffix":""},{"id":307847476,"identity":"c63bd9f2-028e-44e1-bcc5-8f630eaa2e0c","order_by":3,"name":"Theo Spira","email":"","orcid":"https://orcid.org/0009-0008-8183-8775","institution":"University of Gothenburg","correspondingAuthor":false,"prefix":"","firstName":"Theo","middleName":"","lastName":"Spira","suffix":""},{"id":307847477,"identity":"adbda336-723b-4bb4-8aa7-f4402ae7c46e","order_by":4,"name":"Anne Braakmann-Folgmann","email":"","orcid":"","institution":"The Arctic University of Norway (UiT)","correspondingAuthor":false,"prefix":"","firstName":"Anne","middleName":"","lastName":"Braakmann-Folgmann","suffix":""},{"id":307847478,"identity":"abe5bad3-33cf-4d9a-a3b9-5602c8e7132b","order_by":5,"name":"Einar Povl Abrahamsen","email":"","orcid":"https://orcid.org/0000-0001-5924-5350","institution":"British Antarctic Survey","correspondingAuthor":false,"prefix":"","firstName":"Einar","middleName":"Povl","lastName":"Abrahamsen","suffix":""},{"id":307847479,"identity":"e99be40f-b5e6-44da-a531-fac1b054e05a","order_by":6,"name":"Michael Meredith","email":"","orcid":"https://orcid.org/0000-0002-7342-7756","institution":"British Antarctic Survey","correspondingAuthor":false,"prefix":"","firstName":"Michael","middleName":"","lastName":"Meredith","suffix":""},{"id":307847480,"identity":"20d28238-2c2f-422c-a5a5-815d3999794b","order_by":7,"name":"Geraint Tarling","email":"","orcid":"https://orcid.org/0000-0002-3753-5899","institution":"British Antarctic Survey","correspondingAuthor":false,"prefix":"","firstName":"Geraint","middleName":"","lastName":"Tarling","suffix":""}],"badges":[],"createdAt":"2024-05-15 13:56:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4425629/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4425629/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41561-025-01659-7","type":"published","date":"2025-04-04T04:00:00+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":79954052,"identity":"2043a8fd-b439-4f47-bc33-59678888a9d3","added_by":"auto","created_at":"2025-04-05 07:07:20","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4466092,"visible":true,"origin":"","legend":"Article File","description":"","filename":"A68AsubmitNaturelineNumb.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4425629/v1_covered_3af853a8-991a-4958-ae16-1b17c55e107d.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Giant icebergs increase mixing and stratification in upper-ocean layers","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"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":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"iceberg, glider, ocean mixing, winter water, melting, cryosphere, Southern Ocean, Antarctica","lastPublishedDoi":"10.21203/rs.3.rs-4425629/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4425629/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Ice sheet mass loss is one of the clearest manifestations of climate change, with Antarctica discharging mass into the ocean via the melting of glacial ice or through calving. This calving produces icebergs which can modify ocean water properties, often at great distances from source. This affects upper ocean physics and primary productivity, with implications for atmospheric carbon drawdown. Detailed understanding of iceberg modification of ocean waters has hitherto been hindered by a lack of proximal measurements. Here, unique measurements of a giant iceberg from an underwater glider quantifies meltwater effects on the physical and biological processes in the upper layers of the Southern Ocean, a region disproportionately important for global heat and carbon sequestration. Iceberg basal melting erodes seasonally-produced Winter Water (WW) layer stratification, normally forming a strong potential energy barrier to vertical exchange of surface and deep waters, whilst freshwater runoff increases and shoals near-surface stratification. Nutrient-rich deeper waters, incorporating terrigenous loaded meltwater, are ventilated to below this stratification maxima, providing a potential mechanism for alleviating critical biological limiting components. Regional historical hydrographic data demonstrates similar stratification changes during the passage of another large iceberg, suggesting that they may be an important pathway of aseasonal WW modification.","manuscriptTitle":"Giant icebergs increase mixing and stratification in upper-ocean layers","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-06-11 02:42:05","doi":"10.21203/rs.3.rs-4425629/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"nature-geoscience","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"ngeo","sideBox":"Learn more about [Nature Geoscience](http://www.nature.com/ngeo/)","snPcode":"","submissionUrl":"","title":"Nature Geoscience","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature Research","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"c311f547-d273-4598-8ff2-9d2668c77e89","owner":[],"postedDate":"June 11th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":32517883,"name":"Physical sciences/Physics/Fluid dynamics"},{"id":32517884,"name":"Earth and environmental sciences/Ocean sciences/Physical oceanography"},{"id":32517885,"name":"Earth and environmental sciences/Climate sciences/Ocean sciences/Physical oceanography"},{"id":32517886,"name":"Earth and environmental sciences/Climate sciences/Climate change/Projection and prediction"},{"id":32517887,"name":"Earth and environmental sciences/Biogeochemistry/Carbon cycle"}],"tags":[],"updatedAt":"2025-04-05T07:07:10+00:00","versionOfRecord":{"articleIdentity":"rs-4425629","link":"https://doi.org/10.1038/s41561-025-01659-7","journal":{"identity":"nature-geoscience","isVorOnly":false,"title":"Nature Geoscience"},"publishedOn":"2025-04-04 04:00:00","publishedOnDateReadable":"April 4th, 2025"},"versionCreatedAt":"2024-06-11 02:42:05","video":"","vorDoi":"10.1038/s41561-025-01659-7","vorDoiUrl":"https://doi.org/10.1038/s41561-025-01659-7","workflowStages":[]},"version":"v1","identity":"rs-4425629","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4425629","identity":"rs-4425629","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}