ESSDD Earth System Science Data Discussions ESSDD Earth Syst. Sci. Data Discuss. Göttingen, Germany 10.5194/essd-2026-699 MioOcean: database compilation and temperature proxy systematics in the Miocene oceans Sosdian Sindia M. 1 33 Auderset Alexandra https://orcid.org/0000-0002-6316-4980 2 33 Modestou Sevasti https://orcid.org/0000-0002-9820-5551 3 Holbourn Ann 4 34 Boscolo-Galazzo Flavia https://orcid.org/0000-0002-5146-5321 5 Drury Anna Joy https://orcid.org/0000-0001-6206-7284 6 7 Hess Anya V. 8 Kochhann Karlos G. D. https://orcid.org/0000-0001-5339-1103 9 10 Liebrand Diederik https://orcid.org/0000-0002-6925-7889 7 Liu Xiaoqing https://orcid.org/0000-0001-7647-7364 11 Nirenberg Jared 12 13 Shah Neeraj S. 14 Tangunan Deborah https://orcid.org/0000-0002-1078-5767 1 7 Auer Gerald https://orcid.org/0000-0002-2574-0027 5 Badger Marcus P. S. https://orcid.org/0000-0001-8195-5244 15 Bolton Clara https://orcid.org/0000-0002-3078-1253 16 Clark Alexander https://orcid.org/0000-0002-6949-3187 17 18 Crocker Anya https://orcid.org/0000-0001-9561-5750 2 17 Evans David https://orcid.org/0000-0002-8685-671X 2 Feakins Sarah https://orcid.org/0000-0003-3434-2423 11 Herbert Timothy https://orcid.org/0000-0003-1556-4290 12 Judd Emily https://orcid.org/0000-0003-3573-3610 20 Kasbohm Jennifer https://orcid.org/0000-0002-8154-6173 21 King David 1 7 Krijgsman Wout 22 Kuhnt Wolfgang 4 Lawrence Kira 12 Lear Caroline H. https://orcid.org/0000-0002-7533-4430 1 Marshall-Mills Kim 1 23 McClymont Erin https://orcid.org/0000-0003-1562-8768 19 Meckler Nele 24 Minton Paul 7 Nilsson-Kerr Katrina 24 Ochoa Diana 25 Robinson Marci 26 Sakthivel Thamizharasan https://orcid.org/0000-0002-6593-7713 27 Sangiorgi Francesca https://orcid.org/0000-0003-4233-6154 22 Shevenell Amelia E. 28 Si Weimin https://orcid.org/0000-0002-3835-3376 12 Sibert Elizabeth 29 Sliwinska Kasia K. https://orcid.org/0000-0001-5488-8832 30 Sluijs Appy https://orcid.org/0000-0003-2382-0215 22 Stoll Heather https://orcid.org/0000-0002-2953-7835 18 Taylor Victoria https://orcid.org/0000-0002-6909-1575 24 van Peer Tim https://orcid.org/0000-0003-3516-4198 6 Wade Bridget https://orcid.org/0000-0002-7245-8614 7 Westerhold Thomas https://orcid.org/0000-0001-8151-4684 31 Wubben Evi https://orcid.org/0000-0002-2478-0748 22 Zhang Yige https://orcid.org/0000-0001-7331-1246 32 Ziegler Martin https://orcid.org/0000-0003-3198-6434 22 School of Earth and Environmental Sciences, Cardiff University, Cardiff, CF10 3AT, UK School of Ocean and Earth Sciences, University of Southampton, Southampton, SO14 3ZH, UK School of Geography and Natural Sciences, University of Northumbria, Newcastle upon Tyne, NE1 8ST, UK Institute of Geosciences, Kiel University, Olshausenstraße 40, 24118 Kiel, Germany Department of Earth Sciences, NAWI Graz Geocenter, University of Graz, Graz, Austria School of Geography, Geology and the Environment, University of Leicester, Leicester, UK Department of Earth Sciences, University College London, London, UK George Mason University, Fairfax, VA, USA GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany Technological Institute for Paleoceanography and Climate Change (itt Oceaneon), Universidade do Vale do Rio dos Sinos (UNISINOS University), São Leopoldo, Brazil Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN, USA Department of Earth, Environmental, and Planetary Sciences, Brown University, Providence, RI, USA Department of Earth and Environmental Sciences, Syracuse University, Syracuse, NY, USA Independent researcher School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, UK Aix-Marseille Univ., CNRS, IRD, INRAE, CEREGE, Aix-en-Provence, France Climate Geochemistry Department, Max Planck Institute for Chemistry, Mainz, Germany Department of Earth and Planetary Sciences, ETH Zurich, Zurich, Switzerland Department of Geography, Durham University, Durham, UK Earth Sciences New Zealand, Auckland, New Zealand Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC, USA Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands Marine Conservation Society, Ross Park, Ross-on-Wye, UK Department of Earth Science and Bjerknes Centre for Climate Research, University of Bergen, Bergen, Norway Departamento de Geología, Universidad de Salamanca, Salamanca, Spain William & Mary, Geology Department, Williamsburg, VA, USA Wadia Institute of Himalayan Geology, Dehradun, India College of Marine Science, University of South Florida, St. Petersburg, FL, USA Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark Center for Marine Environmental Sciences (MARUM), University of Bremen, Bremen, Germany State Key Laboratory of Deep Earth Processes and Resources (DEEPER), Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China These authors contributed equally to this work. deceased 27 10 2026 2026 1 49 Copyright: © 2026 Sindia M. Sosdian et al. 2026 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://essd.copernicus.org/preprints/essd-2026-699/ The full text article is available as a PDF file from https://essd.copernicus.org/preprints/essd-2026-699/essd-2026-699.pdf

The Miocene epoch has been highlighted as containing reference intervalsfor near future warmer climates; however, to realize the full potential of this analogue, discrepancies must be addressed, including those between model predictions and proxy data for ocean temperatures. Over recent years, new insights into ocean temperature proxy systematics have come to light, thus providing robust Miocene ocean temperature estimates requires re-evaluation of available data. In tandem, collaboration between stratigraphers and geochemists emphasises the importance of refining and synchronising age models to ensure robust comparisons of temperature patterns across space and time. Here, we compiled published Miocene temperature proxy records from 101 publications and 94 sites into the new MioOcean database, recalculated temperatures using state of the art proxy constraints, and revised and/or verified age models for 38 key sites. The MioOcean database includes upper and bottom ocean temperature records from organic (U<sup>K&rsquo;</sup><sub>37</sub> and TEX<sub>86</sub>) and inorganic (Mg/Ca, &delta;<sup>18</sup>O, and &Delta;<sub>47</sub>) marine geochemical proxies. To improve confidence in, and comparability between, datasets, we convert proxies into temperature in an internally consistent manner, including updating all associated input variables. To aid usability, the database provides propagated numerical uncertainty estimates encompassing as many sources of error as possible. The MioOcean database improves accessibility of proxy-based Miocene ocean temperature reconstructions to non-specialists, simplifies model-data comparison and validation, and provides the necessary groundwork for in-depth inter-proxy comparison studies. The data compilation (<a href="https://doi.org/10.5281/zenodo.22258386" target="_blank" rel="noopener">https://doi.org/10.5281/zenodo.22258386</a>, Sosdian et al., 2026) is also hosted on <a href="https://www.mioocean.com" target="_blank" rel="noopener">www.mioocean.com</a>, including interactive data visualization, enabling interrogation and comparison of re-evaluated MioOcean records.

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