Ventilation and buffering capacity effects on ocean acidification in low oxygen environments
Date
2025-12-19
Journal Title
Journal ISSN
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Publisher
Nature Communications
Abstract
Ocean acidification results from oceanic uptake of anthropogenic CO2 (ΔCant). Weak carbonate buffering capacity (high Revelle factor, RF) amplifies acidification, but its role in persistently low-oxygen, poorly ventilated regions is unclear. Here we compare preindustrial to present changes in partial pressure of CO2 (pCO2), hydrogen ion concentration ([H+]), pH, aragonite saturation state (Ωara), and RF within permanent oxygen minimum zones (OMZs) versus well-ventilated regions. We find that acidification is negligible in the least-ventilated, poorly buffered lower OMZs, but detectable in moderately ventilated upper OMZs. In upper OMZs, pCO2 and [H+] increase faster while Ωara, pH, and RF change more slowly than in adjacent well-ventilated regions. Our analysis reveals that limited ΔCant delivery by ventilation ultimately constrain acidification in low-oxygen regions. Accordingly, low-oxygen regions with poor ventilation will experience less acidification than well-ventilated regions, and different metrics (notably [H+] versus Ωara) respond distinctly due to their different definitions and sensitivities.
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This article was originally published in Nature Communications. The version of record is available at: https://doi.org/10.1038/s41467-025-67807-0
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Citation
Xue, L., Sabine, C., Chen, J. et al. Ventilation and buffering capacity effects on ocean acidification in low oxygen environments. Nat Commun 17, 228 (2026). https://doi.org/10.1038/s41467-025-67807-0