Recommendations from the Ocean Carbonate System Intercomparison Forum: Quantifying and reducing uncertainties in the calculations of carbonate system equilibrium in the oceans

Published

December 14, 2023

Author(s)

Brendan Carter, Jonathan Sharp, Andrew Dickson, Marta Álvarez, Michael Fong, Maribel García-Ibáñez, Ryan Woosley, Takeshita Yuichiro, Leticia Barbero, Robert Byrne, Wei-Jun Cai, Melissa Chierici, Simon Clegg, Regina Easley, Andrea Fassbender, Kalla Fleger, Xinyu Li, Macarena Martín-Mayor, Katelyn Schockman, Aleck Wang Zhaohui

Abstract

The ocean carbonate system is critical to monitor because it plays a major role in regulating Earth's climate and marine ecosystems. It is monitored using a variety of measurements, and it is commonly understood that all major components of the seawater carbonate system can be calculated when at least two carbonate system variables are measured. However, several recent studies have highlighted systematic discrepancies between calculated and directly measured carbonate parameters and these discrepancies have large implications for efforts to measure and quantify the changing ocean carbon cycle. Given this, the Ocean Carbonate System Intercomparison Forum (OCSIF) was formed as a working group through the Ocean Carbon and Biogeochemistry (OCB) program to coordinate and recommend research to quantify and/or reduce uncertainties in marine carbonate system measurements and calculations, identify unknown or overlooked sources of these uncertainties, and provide recommendations for making progress on community efforts despite these uncertainties. With this paper we aim to deliver on these goals by summarizing recent progress toward quantifying and reducing carbonate system uncertainties; presenting a small amount of new data, metadata, and analysis related to uncertainties in carbonate system measurements; advocating for research to further reduce and better quantify carbonate system measurement uncertainties; and restating and explaining the rationales behind several OCSIF recommendations made at community meetings. We focus on open ocean carbonate chemistry, and caution that the considerations we discuss become further complicated in coastal, estuarine, and sedimentary environments.

Citation

Limnology and Oceanography

Pub Type

Journals

Download Paper

https://doi.org/10.1002/lno.12477

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Keywords

pH, ocean acidification, biogeochemistry

Citation

Carter, B. , Sharp, J. , Dickson, A. , Álvarez, M. , Fong, M. , García-Ibáñez, M. , Woosley, R. , Yuichiro, T. , Barbero, L. , Byrne, R. , Cai, W. , Chierici, M. , Clegg, S. , Easley, R. , Fassbender, A. , Fleger, K. , Li, X. , Martín-Mayor, M. , Schockman, K. and Wang Zhaohui, A. (2023), Recommendations from the Ocean Carbonate System Intercomparison Forum: Quantifying and reducing uncertainties in the calculations of carbonate system equilibrium in the oceans, Limnology and Oceanography, [online], https://doi.org/10.1002/lno.12477, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=936930 (Accessed October 8, 2025)