Emerging outflow of not-so-dense shelf water from an East Antarctic polynya

Emerging outflow of not-so-dense shelf water from an East Antarctic polynya | 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 Article Emerging outflow of not-so-dense shelf water from an East Antarctic polynya Kaihe Yamazaki, Annie Foppert, Kathryn Gunn, Haruhiko Kashiwase, and 8 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6738704/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 12 Jan, 2026 Read the published version in Communications Earth & Environment → Version 1 posted You are reading this latest preprint version Abstract East Antarctic coastal polynyas are vital for Antarctic Bottom Water (AABW) formation, thereby redistributing heat and carbon globally. The Dibble Polynya, off Wilkes Land, is recognised for its pronounced sea ice production, yet the properties of shelf water there and its influence on offshore AABW have not been reported. Here we show the first observational evidence of Dense Shelf Water (DSW) outflow from the Dibble Polynya, ventilating a lighter variety of local AABW (28.27–28.30 kg m⁻³ γn). Hydrographic records show DSW formation has persisted for over 50 years, consistent with steady satellite-derived sea ice production since the 1990s. Since the 2010s, cross-slope salinity gradient in AABW downstream of the Dibble Polynya has distinctly weakened, with the nearby Antarctic Slope Front structure modified concurrently. This followed a sharp decline in sea ice production in the neighbouring Mertz Polynya caused by post-2010 icescape changes. Our results suggest DSW outflow recently emerged from the Dibble Polynya is advantaged by the reduction of denser AABW upstream, potentially weakening the Antarctic Slope Current and its barrier to the cross-slope exchange. As the densest AABW layers are rapidly diminishing in a warming climate, not-so-dense shelf water from the mid-sized polynya efficiently ventilates the abyssal basin. Earth and environmental sciences/Ocean sciences/Physical oceanography Earth and environmental sciences/Climate sciences/Cryospheric science Earth and environmental sciences/Climate sciences/Ocean sciences/Physical oceanography Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Published Journal Publication published 12 Jan, 2026 Read the published version in Communications Earth & Environment → 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-6738704","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":463860782,"identity":"9eb4ad1f-f451-45d5-8b90-57f95f9b1cd8","order_by":0,"name":"Kaihe 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