1. D. R. Turner, E. P. Achterberg, C.-T. A. Chen, S. L. Clegg, V. Hatje, M. Maldonado, S. G. Sander, C. M. van den Berg, and M. Wells (2016) Towards a quality-controlled and accessible Pitzer model for seawater and related systems. Frontiers in Marine Science 3, art. 139; https://doi.org/10.3389/fmars.2016.00139.
2. S. L. Clegg (2016-2017) The sensitivity of calculated seawater pH (total and free scales), and calcite and aragonite saturation, to Pitzer model parameter values. Recommendations for new measurements of thermodynamic properties. [Download]
In this report we make recommendations for new measurements of thermodynamic properties, in order of their importance for the calculation of pH (on both total and free scales), and calcite or aragonite saturation, using Pitzer chemical speciation models. The work described here is being used to guide our experiments (being carried out at Scripps Institution of Oceanography by Andrew Dickson, by Eric Achterberg at GEOMAR in Kiel, and by colleagues at national metrological institutes in Europe and Japan).
3. D. R. Turner, H. Benway and S. L. Clegg (2018) The results of surveys of user needs for chemical speciation modelling tools. [Download]
In this document we present the results of two online surveys of the chemical oceanography community regarding regarding their needs for practical chemical speciation models for natural waters (mainly, but not exclusively, seawater). The surveys address a number of questions, including: the chemical media and solute species of interest; the level of knowledge expected of the users; program operation (e.g., web-based or free-standing); how the results of calculations should be presented; and the levels of help, training, and support required.
The survey results will inform the design of the speciation modelling tools that will be one of the main outputs of the Working Group.
4. P. Lodeiro, D. R. Turner, E. P. Achterberg, F. K. A. Gregson, J. P. Reid, and S. L. Clegg (2021) Solid-liquid equilibria in aqueous solutions of Tris, Tris-NaCl, Tris-TrisHCl, and Tris-(TrisH)2SO4 at temperatures from 5 to 45 oC. J. Chem. & Eng. Data 66, 437-455; https://dx.doi.org/10.1021/acs.jced.0c00744.
5. M. P. Humphreys, J. F. Waters, D. R. Turner, A. G. Dickson, and S. L. Clegg (2022) Chemical speciation models based upon the Pitzer activity coefficient equations, including the propagation of uncertainties: Artificial seawater from 0 to 45 °C. Mar. Chem. 244, art. 104095.
6. S. L. Clegg, M. P. Humphreys, J. F. Waters, D. R. Turner, and A. G. Dickson (2022) Chemical speciation models based upon the Pitzer activity coefficient equations, including the propagation of uncertainties. II. Tris buffers in artificial seawater at 25 oC, and an assessment of the seawater ‘Total’ pH scale. Mar. Chem. 244, art. 104096.
7. S. L. Clegg, J. F. Waters, D. R. Turner, and A. G. Dickson (2023) Chemical speciation models based upon the Pitzer activity coefficient equations, including the propagation of uncertainties. III. Seawater from
the freezing point to 45 ◦C, including acid-base equilibria.
8. D. R. Turner and S. L. Clegg (2023) Sources of Pitzer parameters and equilibrium constants for the GEOTRACES core elements included in the SCOR Working Group 145 chemical speciation model. [Download]