23f5cde7-eeef-44d5-8d6f-43f2046fe944 ETT S.p.A. 2026-08-26T15:55:19 ISO 19115:2003/19139 1.0 WGS 1984 Freshwater Sources in the Global Ocean through Salinity-d18O Relationships: A Machine Learning Solution to a Water Mass Problem 2025-10-15 10.5281/zenodo.17357937 This dataset contains point estimates of meteoric water and sea-ice meltwater fractions in polar ocean water masses, together with estimates of the global stable oxygen isotopic composition (d18O) of meteoric water. The estimates were inferred from co-located d18O, salinity and temperature observations from NASA-GISS and CISE-LOCEAN datasets and individual cruise data available through the British Oceanographic Data Centre, using a Self Organizing Map machine-learning approach to identify distinct salinity-d18O relationships in water masses. To quantify freshwater-source fractions in ocean water masses and characterize salinity-d18O relationships using a machine-learning approach. This dataset was produced within the OCEAN ICE project (Ocean-Cryosphere Exchanges in Antarctica: Impacts on Climate and the Earth System), funded by the European Union under Horizon Europe Grant Agreement No. 101060452. NORCE Research AS NORCE Research AS National Oceanography Centre Woods Hole Oceanographic Institution British Antarctic Survey https://catalog.s4oceanice.eu:/geonetwork/srv/api/records/23f5cde7-eeef-44d5-8d6f-43f2046fe944/attachments/cropped-o_ice_logo2-2-1.webp Meteoric Water Sea Ice Meltwater Freshwater Ocean Oxygen Isotopes salinity Self Organizing Map machine learning OCEAN ICE Antarctica Southern Ocean Continents, countries, sea regions of the world. 2015-07-17 geonetwork.thesaurus.external.place.regions Oceanographic geographical features GEMET - INSPIRE themes, version 1.0 2008-06-01 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme OCEAN CURRENTS OCEAN CIRCULATION WATER TEMPERATURE SALINITY ICE DRAFT Global Change Master Directory (GCMD) Keywords 2026-08-06 geonetwork.thesaurus.external.theme.ardc-curated_gcmd-sciencekeywords_19-4-2024-09-06 Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/ oceans -180.00 180.00 -90.00 90.00 This dataset was produced within the OCEAN ICE project (Ocean-Cryosphere Exchanges in Antarctica: Impacts on Climate and the Earth System), funded by the European Union under Horizon Europe Grant Agreement No. 101060452. NetCDF https://zenodo.org/records/17357937 WWW:LINK-1.0-http--link Freshwater Sources dataset on Zenodo Zenodo repository record, DOI and access point for Ocean_freshwater_sources_fractions.nc. https://doi.org/10.1029/2024JC022122 WWW:LINK-1.0-http--link Associated JGR: Oceans publication Scientific publication describing the dataset and machine-learning methodology. Co-located observations of stable oxygen isotopic composition (d18O), salinity and temperature from NASA-GISS and CISE-LOCEAN datasets, complemented by individual cruise observations available through the British Oceanographic Data Centre, were assembled and analysed using a Self Organizing Map machine-learning method. The method identifies distinct salinity-d18O relationships among water masses and was used to infer point estimates of meteoric-water and sea-ice-meltwater fractions and the stable oxygen isotopic composition of meteoric water. The resulting derived estimates are distributed as a NetCDF file.