Articles | Volume 18, issue 4
https://doi.org/10.5194/bg-18-1407-2021
© Author(s) 2021. 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-18-1407-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Technical note
| 
24 Feb 2021
Technical note |
| 24 Feb 2021
| 24 Feb 2021
Technical note: Interpreting pH changes
Andrea J. Fassbender
CORRESPONDING AUTHOR
Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss
Landing, CA 95039, USA
James C. Orr
LSCE/IPSL, Laboratoire des Sciences du Climat et de l'Environnement,
CEA-CNRS-UVSQ, Gif-sur-Yvette, France
Andrew G. Dickson
Scripps Institution of Oceanography, University of California, San
Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
Viewed
Total article views: 7,075 (including HTML, PDF, and XML)
Cumulative views and downloads
(calculated since 12 Oct 2020)
| HTML | XML | Total | Supplement | BibTeX | EndNote | |
|---|---|---|---|---|---|---|
| 4,589 | 2,339 | 147 | 7,075 | 620 | 153 | 185 |
- HTML: 4,589
- PDF: 2,339
- XML: 147
- Total: 7,075
- Supplement: 620
- BibTeX: 153
- EndNote: 185
Total article views: 5,587 (including HTML, PDF, and XML)
Cumulative views and downloads
(calculated since 24 Feb 2021)
| HTML | XML | Total | Supplement | BibTeX | EndNote | |
|---|---|---|---|---|---|---|
| 3,793 | 1,660 | 134 | 5,587 | 364 | 140 | 166 |
- HTML: 3,793
- PDF: 1,660
- XML: 134
- Total: 5,587
- Supplement: 364
- BibTeX: 140
- EndNote: 166
Total article views: 1,488 (including HTML, PDF, and XML)
Cumulative views and downloads
(calculated since 12 Oct 2020)
| HTML | XML | Total | Supplement | BibTeX | EndNote | |
|---|---|---|---|---|---|---|
| 796 | 679 | 13 | 1,488 | 256 | 13 | 19 |
- HTML: 796
- PDF: 679
- XML: 13
- Total: 1,488
- Supplement: 256
- BibTeX: 13
- EndNote: 19
Viewed (geographical distribution)
Total article views: 7,075 (including HTML, PDF, and XML)
Thereof 6,584 with geography defined
and 491 with unknown origin.
Total article views: 5,587 (including HTML, PDF, and XML)
Thereof 5,377 with geography defined
and 210 with unknown origin.
Total article views: 1,488 (including HTML, PDF, and XML)
Thereof 1,207 with geography defined
and 281 with unknown origin.
| Country | # | Views | % |
|---|
| Country | # | Views | % |
|---|
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1
1
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1
1
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1
1
Cited
39 citations as recorded by crossref.
- Assessing the influence of ocean alkalinity enhancement on a coastal phytoplankton community A. Ferderer et al. https://doi.org/10.5194/bg-19-5375-2022
- Emergent interactive effects of climate change and contaminants in coastal and ocean ecosystems V. Hatje et al. https://doi.org/10.3389/fmars.2022.936109
- Limits and CO2equilibration of near-coast alkalinity enhancement J. He & M. Tyka https://doi.org/10.5194/bg-20-27-2023
- Extensive Remineralization of Peatland‐Derived Dissolved Organic Carbon and Ocean Acidification in the Sunda Shelf Sea, Southeast Asia Y. Zhou et al. https://doi.org/10.1029/2021JC017292
- Re-evaluation of carbonic acid dissociation constants across conditions and the implications for ocean acidification R. Woosley & J. Moon https://doi.org/10.1016/j.marchem.2023.104247
- Southern Ocean Acidification Revealed by Biogeochemical‐Argo Floats M. Mazloff et al. https://doi.org/10.1029/2022JC019530
- Amplified bottom water acidification rates on the Bering Sea shelf from 1970–2022 D. Pilcher et al. https://doi.org/10.5194/bg-22-3103-2025
- Impact of coupling biochar and clay minerals on physicochemical properties of sandy soils and CH4/CO2 flux for agriculture A. Ads et al. https://doi.org/10.1016/j.jenvman.2026.128881
- Stabilization of Indian peat using alkali-activated ground granulated blast furnace slag S. Khanday et al. https://doi.org/10.1007/s10064-021-02248-9
- Field Application of Automated Spectrophotometric Analyzer for High-Resolution In Situ Monitoring of pH in Dynamic Estuarine and Coastal Waters M. Nehir et al. https://doi.org/10.3389/fmars.2022.891876
- Acidification of the Nordic Seas F. Fransner et al. https://doi.org/10.5194/bg-19-979-2022
- Ocean Acidification and Long‐Term Changes in the Carbonate System Properties of the South Atlantic Ocean A. Piñango et al. https://doi.org/10.1029/2021GB007196
- The role of seagrass in modifying dissolved oxygen and pH in coastal systems: A meta-analysis A. Mohamed et al. https://doi.org/10.1016/j.ecss.2026.109845
- Commentary: Overstated Potential for Seagrass Meadows to Mitigate Coastal Ocean Acidification A. Ricart et al. https://doi.org/10.3389/fmars.2022.884857
- A 37-year record of ocean acidification in the Southern California current W. Wolfe et al. https://doi.org/10.1038/s43247-023-01065-0
- Divergent trajectories of ocean warming and acidification E. Mortenson et al. https://doi.org/10.1088/1748-9326/ac3d57
- Soil organic matter interactions along the elevation gradient of the James Ross Island (Antarctica) V. Vlček et al. https://doi.org/10.5194/soil-10-813-2024
- Review—Nanopillar Structure in the Direction of Optical Biosensor On-Chip Integration A. Pradana et al. https://doi.org/10.1149/1945-7111/abfb3a
- Long-Term Trends in Estuarine Carbonate Chemistry in the Northwestern Gulf of Mexico M. McCutcheon & X. Hu https://doi.org/10.3389/fmars.2022.793065
- Stabilization of organic soil using GGBS-based geopolymer and hybrid alkali-activated cement: a deep mixing model approach M. Singh et al. https://doi.org/10.1080/19386362.2025.2507735
- Global Surface Ocean Acidification Indicators From 1750 to 2100 L. Jiang et al. https://doi.org/10.1029/2022MS003563
- Dissimilar Sensitivities of Ocean Acidification Metrics to Anthropogenic Carbon Accumulation in the Central North Pacific Ocean and California Current Large Marine Ecosystem M. Arroyo et al. https://doi.org/10.1029/2022GL097835
- Daily variability of pH and temperature in seawater from a near-pristine oceanic atoll, Southwest Atlantic M. de Almeida et al. https://doi.org/10.1016/j.marpolbul.2023.115670
- Ion Trios: Cause of Ion Specific Interactions in Aqueous Solutions and Path to a Better pH Definition P. May & E. May https://doi.org/10.1021/acsomega.4c07525
- Ventilation and buffering capacity effects on ocean acidification in low oxygen environments L. Xue et al. https://doi.org/10.1038/s41467-025-67807-0
- High-resolution monitoring of the pH under strong La Niña conditions in Gorgona Island, Colombian Pacific, Panama Bight A. Murcia et al. https://doi.org/10.3389/fmars.2025.1595871
- Overstated Potential for Seagrass Meadows to Mitigate Coastal Ocean Acidification B. Van Dam et al. https://doi.org/10.3389/fmars.2021.729992
- Amplified Subsurface Signals of Ocean Acidification A. Fassbender et al. https://doi.org/10.1029/2023GB007843
- Estuarine acidification mirrors the ocean trend and correlates with the El Niño Southern Oscillation J. Grear https://doi.org/10.1002/lno.70167
- Junction potentials in electrochemical cells with transference: A review and prescription to end over 70 years of sleepwalking P. May & E. May https://doi.org/10.1016/j.electacta.2025.147087
- S.P.L. Sørensen, the pH concept and its early history H. Kragh https://doi.org/10.1007/s10698-025-09532-6
- Progression of ocean interior acidification over the industrial era J. Müller & N. Gruber https://doi.org/10.1126/sciadv.ado3103
- Unraveling natural carbonate variability in Narragansett Bay, RI using multiple high temporal resolution pH time series A. Baskind et al. https://doi.org/10.3389/fmars.2025.1552350
- Vertical distribution of pH in the top ~10 m of deep-ocean sediments: Analysis of a unique dataset C. Shao et al. https://doi.org/10.3389/fmars.2023.1126704
- A century of change in the California Current: upwelling system amplifies acidification M. Stoll et al. https://doi.org/10.1038/s41467-025-63207-6
- Marine CO2 system variability along the northeast Pacific Inside Passage determined from an Alaskan ferry W. Evans et al. https://doi.org/10.5194/bg-19-1277-2022
- Revisiting the ocean acidification planetary boundary H. Findlay & R. Feely https://doi.org/10.1093/nsr/nwag173
- Contrasting Controls of Acidification Metrics Across Environmental Gradients in the North Pacific and the Adjunct Arctic Ocean: Insight From a Transregional Study Y. Wu et al. https://doi.org/10.1029/2021GL094473
- Dynamically downscaled projections of ocean acidification for the Bering Sea D. Pilcher et al. https://doi.org/10.1016/j.dsr2.2022.105055
39 citations as recorded by crossref.
- Assessing the influence of ocean alkalinity enhancement on a coastal phytoplankton community A. Ferderer et al. https://doi.org/10.5194/bg-19-5375-2022
- Emergent interactive effects of climate change and contaminants in coastal and ocean ecosystems V. Hatje et al. https://doi.org/10.3389/fmars.2022.936109
- Limits and CO2equilibration of near-coast alkalinity enhancement J. He & M. Tyka https://doi.org/10.5194/bg-20-27-2023
- Extensive Remineralization of Peatland‐Derived Dissolved Organic Carbon and Ocean Acidification in the Sunda Shelf Sea, Southeast Asia Y. Zhou et al. https://doi.org/10.1029/2021JC017292
- Re-evaluation of carbonic acid dissociation constants across conditions and the implications for ocean acidification R. Woosley & J. Moon https://doi.org/10.1016/j.marchem.2023.104247
- Southern Ocean Acidification Revealed by Biogeochemical‐Argo Floats M. Mazloff et al. https://doi.org/10.1029/2022JC019530
- Amplified bottom water acidification rates on the Bering Sea shelf from 1970–2022 D. Pilcher et al. https://doi.org/10.5194/bg-22-3103-2025
- Impact of coupling biochar and clay minerals on physicochemical properties of sandy soils and CH4/CO2 flux for agriculture A. Ads et al. https://doi.org/10.1016/j.jenvman.2026.128881
- Stabilization of Indian peat using alkali-activated ground granulated blast furnace slag S. Khanday et al. https://doi.org/10.1007/s10064-021-02248-9
- Field Application of Automated Spectrophotometric Analyzer for High-Resolution In Situ Monitoring of pH in Dynamic Estuarine and Coastal Waters M. Nehir et al. https://doi.org/10.3389/fmars.2022.891876
- Acidification of the Nordic Seas F. Fransner et al. https://doi.org/10.5194/bg-19-979-2022
- Ocean Acidification and Long‐Term Changes in the Carbonate System Properties of the South Atlantic Ocean A. Piñango et al. https://doi.org/10.1029/2021GB007196
- The role of seagrass in modifying dissolved oxygen and pH in coastal systems: A meta-analysis A. Mohamed et al. https://doi.org/10.1016/j.ecss.2026.109845
- Commentary: Overstated Potential for Seagrass Meadows to Mitigate Coastal Ocean Acidification A. Ricart et al. https://doi.org/10.3389/fmars.2022.884857
- A 37-year record of ocean acidification in the Southern California current W. Wolfe et al. https://doi.org/10.1038/s43247-023-01065-0
- Divergent trajectories of ocean warming and acidification E. Mortenson et al. https://doi.org/10.1088/1748-9326/ac3d57
- Soil organic matter interactions along the elevation gradient of the James Ross Island (Antarctica) V. Vlček et al. https://doi.org/10.5194/soil-10-813-2024
- Review—Nanopillar Structure in the Direction of Optical Biosensor On-Chip Integration A. Pradana et al. https://doi.org/10.1149/1945-7111/abfb3a
- Long-Term Trends in Estuarine Carbonate Chemistry in the Northwestern Gulf of Mexico M. McCutcheon & X. Hu https://doi.org/10.3389/fmars.2022.793065
- Stabilization of organic soil using GGBS-based geopolymer and hybrid alkali-activated cement: a deep mixing model approach M. Singh et al. https://doi.org/10.1080/19386362.2025.2507735
- Global Surface Ocean Acidification Indicators From 1750 to 2100 L. Jiang et al. https://doi.org/10.1029/2022MS003563
- Dissimilar Sensitivities of Ocean Acidification Metrics to Anthropogenic Carbon Accumulation in the Central North Pacific Ocean and California Current Large Marine Ecosystem M. Arroyo et al. https://doi.org/10.1029/2022GL097835
- Daily variability of pH and temperature in seawater from a near-pristine oceanic atoll, Southwest Atlantic M. de Almeida et al. https://doi.org/10.1016/j.marpolbul.2023.115670
- Ion Trios: Cause of Ion Specific Interactions in Aqueous Solutions and Path to a Better pH Definition P. May & E. May https://doi.org/10.1021/acsomega.4c07525
- Ventilation and buffering capacity effects on ocean acidification in low oxygen environments L. Xue et al. https://doi.org/10.1038/s41467-025-67807-0
- High-resolution monitoring of the pH under strong La Niña conditions in Gorgona Island, Colombian Pacific, Panama Bight A. Murcia et al. https://doi.org/10.3389/fmars.2025.1595871
- Overstated Potential for Seagrass Meadows to Mitigate Coastal Ocean Acidification B. Van Dam et al. https://doi.org/10.3389/fmars.2021.729992
- Amplified Subsurface Signals of Ocean Acidification A. Fassbender et al. https://doi.org/10.1029/2023GB007843
- Estuarine acidification mirrors the ocean trend and correlates with the El Niño Southern Oscillation J. Grear https://doi.org/10.1002/lno.70167
- Junction potentials in electrochemical cells with transference: A review and prescription to end over 70 years of sleepwalking P. May & E. May https://doi.org/10.1016/j.electacta.2025.147087
- S.P.L. Sørensen, the pH concept and its early history H. Kragh https://doi.org/10.1007/s10698-025-09532-6
- Progression of ocean interior acidification over the industrial era J. Müller & N. Gruber https://doi.org/10.1126/sciadv.ado3103
- Unraveling natural carbonate variability in Narragansett Bay, RI using multiple high temporal resolution pH time series A. Baskind et al. https://doi.org/10.3389/fmars.2025.1552350
- Vertical distribution of pH in the top ~10 m of deep-ocean sediments: Analysis of a unique dataset C. Shao et al. https://doi.org/10.3389/fmars.2023.1126704
- A century of change in the California Current: upwelling system amplifies acidification M. Stoll et al. https://doi.org/10.1038/s41467-025-63207-6
- Marine CO2 system variability along the northeast Pacific Inside Passage determined from an Alaskan ferry W. Evans et al. https://doi.org/10.5194/bg-19-1277-2022
- Revisiting the ocean acidification planetary boundary H. Findlay & R. Feely https://doi.org/10.1093/nsr/nwag173
- Contrasting Controls of Acidification Metrics Across Environmental Gradients in the North Pacific and the Adjunct Arctic Ocean: Insight From a Transregional Study Y. Wu et al. https://doi.org/10.1029/2021GL094473
- Dynamically downscaled projections of ocean acidification for the Bering Sea D. Pilcher et al. https://doi.org/10.1016/j.dsr2.2022.105055
Saved (final revised paper)
Latest update: 05 Jun 2026
Short summary
A decline in upper-ocean pH with time is typically ascribed to ocean acidification. A more quantitative interpretation is often confused by failing to recognize the implications of pH being a logarithmic transform of hydrogen ion concentration rather than an absolute measure. This can lead to an unwitting misinterpretation of pH data. We provide three real-world examples illustrating this and recommend the reporting of both hydrogen ion concentration and pH in studies of ocean chemical change.
A decline in upper-ocean pH with time is typically ascribed to ocean acidification. A more...
Altmetrics
Final-revised paper
Preprint