The recommended dissociation constants for carbonic acid in seawater
Open Access
- 15 January 2000
- journal article
- Published by American Geophysical Union (AGU) in Geophysical Research Letters
- Vol. 27 (2) , 229-232
- https://doi.org/10.1029/1999gl002345
Abstract
A coherent representation of carbonate dissociation constants and measured inorganic carbon species is essential for a wide range of environmentally important issues such as oceanic uptake of anthropogenic CO2 and carbon cycle depictions in ocean circulation models. Previous studies have shown varying degrees of discordance between calculated and measured CO2‐system parameters. It is unclear if this is due to errors in thermodynamic models or in measurements. In this work, we address this issue using a large field dataset (15,300 water samples) covering all ocean basins. Our field data, obtained using laboratory‐calibrated measurement protocols, are most consistent with calculated parameters using the dissociation constants of Mehrbach et al. [1973] as refit by Dickson and Millero [1987]. Thus, these constants are recommended for use in the synthesis of the inorganic carbon data collected during the global CO2 survey during the 1990s and for characterization of the carbonate system in seawater.Keywords
This publication has 17 references indexed in Scilit:
- A comparison of the equilibrium constants for the dissociation of carbonic acid in seawater mediaPublished by Elsevier ,2003
- The role of pHT measurements in marine CO2-system characterizationsDeep Sea Research Part I: Oceanographic Research Papers, 1999
- The pH of buffers based on 2-amino-2-hydroxymethyl-1,3-propanediol (‘tris’) in synthetic sea waterDeep Sea Research Part I: Oceanographic Research Papers, 1998
- Discrete water column measurements of CO2 fugacity and pHT in seawater: A comparison of direct measurements and thermodynamic calculationsMarine Chemistry, 1998
- The carbon dioxide system in the Atlantic OceanJournal of Geophysical Research: Oceans, 1997
- The reliability of the thermodynamic constants for the dissociation of carbonic acid in seawaterMarine Chemistry, 1996
- Spectrophotometric seawater pH measurements: total hydrogen ion concentration scale calibration of m-cresol purple and at-sea resultsDeep Sea Research Part I: Oceanographic Research Papers, 1993
- pH buffers for sea water media based on the total hydrogen ion concentration scaleDeep Sea Research Part I: Oceanographic Research Papers, 1993
- New determination of carbonic acid dissociation constants in seawater as a function of temperature and salinityDeep Sea Research Part A. Oceanographic Research Papers, 1989
- MEASUREMENT OF THE APPARENT DISSOCIATION CONSTANTS OF CARBONIC ACID IN SEAWATER AT ATMOSPHERIC PRESSURE1Limnology and Oceanography, 1973