Articles | Volume 21, issue 2
https://doi.org/10.5194/os-21-537-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/os-21-537-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Control of spatio-temporal variability of ocean nutrients in the East Australian Current
School of the Environment, Faculty of Science, The University of Queensland, Brisbane, Australia
Christopher C. Chapman
CSIRO Environment, Hobart Marine Laboratories, Hobart, Australia
Bernadette M. Sloyan
CSIRO Environment, Hobart Marine Laboratories, Hobart, Australia
Helen Bostock
School of the Environment, Faculty of Science, The University of Queensland, Brisbane, Australia
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Toan Bui, Ming Feng, and Chris Chapman
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-449, https://doi.org/10.5194/essd-2024-449, 2024
Revised manuscript accepted for ESSD
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Time series data are crucial to detect changes in the ocean. Moored instruments have traditionally been used to obtain long-term observations on the continental shelf. However, mooring losses or instrument failures often result in data gaps. Here we present a gap-filled time series dataset of a shelf mooring array off the Western Australian coast, by adopting a machine learning tool to fill the data gaps. The gap-filled data has acceptable errors and shows consistency with observations.
Lea Pesjak, Andrew McMinn, Zanna Chase, and Helen Bostock
Clim. Past, 19, 419–437, https://doi.org/10.5194/cp-19-419-2023, https://doi.org/10.5194/cp-19-419-2023, 2023
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This study uses diatom assemblages, biogenic silica and Si/Al data over the last 140 kyr from core TAN1302-44 (64°54' S, 144°32' E) to define glacial-to-interglacial paleoenvironments near Antarctica with respect to sea ice duration and ocean circulation. It has found that the sea ice season increased gradually during the last glacial, reaching a maximum before decreasing at the end of MIS 2. Following this, Circumpolar Deep Water increased relative to other times prior to ice sheet retreat.
Xavier Crosta, Karen E. Kohfeld, Helen C. Bostock, Matthew Chadwick, Alice Du Vivier, Oliver Esper, Johan Etourneau, Jacob Jones, Amy Leventer, Juliane Müller, Rachael H. Rhodes, Claire S. Allen, Pooja Ghadi, Nele Lamping, Carina B. Lange, Kelly-Anne Lawler, David Lund, Alice Marzocchi, Katrin J. Meissner, Laurie Menviel, Abhilash Nair, Molly Patterson, Jennifer Pike, Joseph G. Prebble, Christina Riesselman, Henrik Sadatzki, Louise C. Sime, Sunil K. Shukla, Lena Thöle, Maria-Elena Vorrath, Wenshen Xiao, and Jiao Yang
Clim. Past, 18, 1729–1756, https://doi.org/10.5194/cp-18-1729-2022, https://doi.org/10.5194/cp-18-1729-2022, 2022
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Despite its importance in the global climate, our knowledge of Antarctic sea-ice changes throughout the last glacial–interglacial cycle is extremely limited. As part of the Cycles of Sea Ice Dynamics in the Earth system (C-SIDE) Working Group, we review marine- and ice-core-based sea-ice proxies to provide insights into their applicability and limitations. By compiling published records, we provide information on Antarctic sea-ice dynamics over the past 130 000 years.
Stefan Mulitza, Torsten Bickert, Helen C. Bostock, Cristiano M. Chiessi, Barbara Donner, Aline Govin, Naomi Harada, Enqing Huang, Heather Johnstone, Henning Kuhnert, Michael Langner, Frank Lamy, Lester Lembke-Jene, Lorraine Lisiecki, Jean Lynch-Stieglitz, Lars Max, Mahyar Mohtadi, Gesine Mollenhauer, Juan Muglia, Dirk Nürnberg, André Paul, Carsten Rühlemann, Janne Repschläger, Rajeev Saraswat, Andreas Schmittner, Elisabeth L. Sikes, Robert F. Spielhagen, and Ralf Tiedemann
Earth Syst. Sci. Data, 14, 2553–2611, https://doi.org/10.5194/essd-14-2553-2022, https://doi.org/10.5194/essd-14-2553-2022, 2022
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Stable isotope ratios of foraminiferal shells from deep-sea sediments preserve key information on the variability of ocean circulation and ice volume. We present the first global atlas of harmonized raw downcore oxygen and carbon isotope ratios of various planktonic and benthic foraminiferal species. The atlas is a foundation for the analyses of the history of Earth system components, for finding future coring sites, and for teaching marine stratigraphy and paleoceanography.
Jacob Jones, Karen E. Kohfeld, Helen Bostock, Xavier Crosta, Melanie Liston, Gavin Dunbar, Zanna Chase, Amy Leventer, Harris Anderson, and Geraldine Jacobsen
Clim. Past, 18, 465–483, https://doi.org/10.5194/cp-18-465-2022, https://doi.org/10.5194/cp-18-465-2022, 2022
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We provide new winter sea ice and summer sea surface temperature estimates for marine core TAN1302-96 (59° S, 157° E) in the Southern Ocean. We find that sea ice was not consolidated over the core site until ~65 ka and therefore believe that sea ice may not have been a major contributor to early glacial CO2 drawdown. Sea ice does appear to have coincided with Antarctic Intermediate Water production and subduction, suggesting it may have influenced intermediate ocean circulation changes.
Kelly-Anne Lawler, Giuseppe Cortese, Matthieu Civel-Mazens, Helen Bostock, Xavier Crosta, Amy Leventer, Vikki Lowe, John Rogers, and Leanne K. Armand
Earth Syst. Sci. Data, 13, 5441–5453, https://doi.org/10.5194/essd-13-5441-2021, https://doi.org/10.5194/essd-13-5441-2021, 2021
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Radiolarians found in marine sediments are used to reconstruct past Southern Ocean environments. This requires a comprehensive modern dataset. The Southern Ocean Radiolarian (SO-RAD) dataset includes radiolarian counts from sites in the Southern Ocean. It can be used for palaeoceanographic reconstructions or to study modern species diversity and abundance. We describe the data collection and include recommendations for users unfamiliar with procedures typically used by the radiolarian community.
Andrew E. Kiss, Andrew McC. Hogg, Nicholas Hannah, Fabio Boeira Dias, Gary B. Brassington, Matthew A. Chamberlain, Christopher Chapman, Peter Dobrohotoff, Catia M. Domingues, Earl R. Duran, Matthew H. England, Russell Fiedler, Stephen M. Griffies, Aidan Heerdegen, Petra Heil, Ryan M. Holmes, Andreas Klocker, Simon J. Marsland, Adele K. Morrison, James Munroe, Maxim Nikurashin, Peter R. Oke, Gabriela S. Pilo, Océane Richet, Abhishek Savita, Paul Spence, Kial D. Stewart, Marshall L. Ward, Fanghua Wu, and Xihan Zhang
Geosci. Model Dev., 13, 401–442, https://doi.org/10.5194/gmd-13-401-2020, https://doi.org/10.5194/gmd-13-401-2020, 2020
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We describe new computer model configurations which simulate the global ocean and sea ice at three resolutions. The coarsest resolution is suitable for multi-century climate projection experiments, whereas the finest resolution is designed for more detailed studies over time spans of decades. The paper provides technical details of the model configurations and an assessment of their performance relative to observations.
Related subject area
Approach: In situ Observations | Properties and processes: Biogeochemistry and nutrient cycles
Alkalinity sources in the Dutch Wadden Sea
Anthropogenic CO2, air–sea CO2 fluxes, and acidification in the Southern Ocean: results from a time-series analysis at station OISO-KERFIX (51° S–68° E)
Mona Norbisrath, Justus E. E. van Beusekom, and Helmuth Thomas
Ocean Sci., 20, 1423–1440, https://doi.org/10.5194/os-20-1423-2024, https://doi.org/10.5194/os-20-1423-2024, 2024
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We present an observational study investigating total alkalinity (TA) in the Dutch Wadden Sea. Discrete water samples were used to identify the TA spatial distribution patterns and locate and shed light on TA sources. By observing a tidal cycle, the sediments and pore water exchange were identified as local TA sources. We assumed metabolically driven CaCO3 dissolution as the TA source in the upper, oxic sediments and anaerobic metabolic processes as TA sources in the deeper, anoxic ones.
Nicolas Metzl, Claire Lo Monaco, Coraline Leseurre, Céline Ridame, Gilles Reverdin, Thi Tuyet Trang Chau, Frédéric Chevallier, and Marion Gehlen
Ocean Sci., 20, 725–758, https://doi.org/10.5194/os-20-725-2024, https://doi.org/10.5194/os-20-725-2024, 2024
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In the southern Indian Ocean, south of the polar front, an observed increase of sea surface fCO2 and a decrease of pH over 1985–2021 are mainly driven by anthropogenic CO2 uptake, but in the last decade (2010–2020) fCO2 and pH were stable in summer, highlighting the competitive balance between anthropogenic CO2 and primary production. In the water column the increase of anthropogenic CO2 concentrations leads to migration of the aragonite saturation state from 600 m in 1985 up to 400 m in 2021.
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Short summary
This study analyses physical and biogeochemical data collected in the East Australian Current (EAC) to understand variability in the nutrient-poor surface waters. The distribution of nutrients in the water column is influenced by seasonal flow and the EAC's position. An inshore EAC has a deeper nutricline and lower nutrient concentrations compared to an offshore EAC position. This has implications for the marine ecosystems along the coastline.
This study analyses physical and biogeochemical data collected in the East Australian Current...