Articles | Volume 22, issue 18
https://doi.org/10.5194/bg-22-5123-2025
© 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/bg-22-5123-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
29 Sep 2025
Research article |
| 29 Sep 2025
| 29 Sep 2025
Hydrodynamic and primary production effects on seasonal DO variability in the Danube River
Department of Geography and Geosciences, Geozentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schlossgarten 5, 91054 Erlangen, Germany
Anna-Neva Visser
Department of Geography and Geosciences, Geozentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schlossgarten 5, 91054 Erlangen, Germany
Christina M. Schubert
Department of Geography and Geosciences, Geozentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schlossgarten 5, 91054 Erlangen, Germany
Simon T. Wander
Department of Geography and Geosciences, Geozentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schlossgarten 5, 91054 Erlangen, Germany
Johannes A. C. Barth
Department of Geography and Geosciences, Geozentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schlossgarten 5, 91054 Erlangen, Germany
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Short summary
We present the first large-scale assessment of the dissolved oxygen (DO) budget and δ18ODO across the Danube to distinguish DO sources and sinks, key for biogeochemical cycles. Two highly productive areas in the warm season showed large deviations (+12.1 ‰) from atmospheric equilibrium (+24.6 ‰ ± 0.4 ‰), unusual for large rivers. Critically low DO in the Sava (0.16 mmol/L) and lower Danube (0.2 mmol/L) in late summer resulted from intensified respiration.
We present the first large-scale assessment of the dissolved oxygen (DO) budget and δ18ODO...
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