- Chair(s)
- David Turner (Sweden)
- Vice-Chair(s)
- Simon Clegg (UK) and Sylvia Sander (New Zealand)
- Other Full Members
- Heather Benway (USA), Arthur Chen (China-Taipei), Andrew Dickson (USA), Vanessa Hatje (Brazil), Maite Maldonado (Canada), Alessandro Tagliabue (UK), and Rodrigo Torres (Chile)
- Associate Members
- Eric Achterberg (Germany), Yuri Artioli (UK), Frank Bastkowski (Physikalisch-Technische Bundesanstalt, Germany), Parthasarathi Chakraborty (India), Peter Croot (Ireland), Regina Easley (National Institute of Standards and Technology, USA) Martha Gledhill (Germany), Igor Maksimov (National Metrology Institute, Japan) Giles Marion (USA), Peter May (Australia), Frank Millero (USA), Ivanka Pizeta (Croatia), Darren Rowland (Australia), Daniela Stoica (Laboratoire national de metrologie et d'essai, France) Pavel Tishchenko (Russia), Stan van den Berg (UK), Wolfgang Voigt (Germany), Christoph Völker (Germany), Feiyue Wang (Canada), and Mona Wells (China)
- Reporter
- Marie-Alexandrine Sicre
- Terms of Reference
To document the current status, and basis in laboratory measurements, of Pitzer models of seawater and estuarine water focusing on the chemistry of ocean acidification and micronutrient trace metals (including, but not limited to, Fe, Cu, Cd, Co, Mn, and Zn). Current capabilities and limitations for oceanographic and biogeochemical calculations will be defined, and future needs established. Important gaps in knowledge, which should have high priority for new measurements, will be identified. The components to be covered will include the seawater electrolytes, the selected trace metals, and buffer solutions and key organic ligands such as those used in CLE-CSV titrations.
To publish the results of the first term of reference in the refereed scientific literature, and to introduce the conclusions and recommendations to the oceanographic community at a “town hall” event or special session at an international ocean sciences meeting.
To specify the functions and capability for a web-based modelling tool that will make chemical speciation calculations easily accessible for a wide range of applications in oceanography research and teaching, and thus improve understanding and spread best practice in modelling.
To implement the web-based tool for chemical speciation calculations, based upon the specification developed in the third term of reference which will also be used to obtain external funding to develop the programs, documentation, and site.
- Approved
- September 2014
- Financial Sponsors
- SCOR, NSF
- Meetings
12-13 April 2015 in Sibenik, Croatia
21 February 2016 in New Orleans, Lousiana, USA
11 February 2018 in Portland, Oregon, USA
16 February 2020 in San Diego, California, USA
- Group Website
- http://marchemspec.org/
- Publications
Toward a Quality-Controlled and Accessible Pitzer Model for Seawater and Related Systems
The prototype chemical speciation modelling software (demonstrated at the 2020 Ocean Sciences Meeting) has been published at: www.aim.env.uea.ac.uk/osm/main_page.html
Chemical speciation modelling code: http://www.aim.env.uea.ac.uk/osm/main_page.html
- Clegg, S. L., Humphreys, M. P., Waters, J. F., Turner, D. R., and Dickson, A. G. (2022). Chemical speciation models based upon the Pitzer activity coefficient equations, including the propagation of uncertainties. II. Tris buffers in artificial seawater at 25 °C, and an assessment of the seawater ‘Total’ pH scale. Marine Chemistry 244, 104096. doi: 10.1016/j.marchem.2022.104096.
- Humphreys, M. P., Waters, J. F., Turner, D. R., Dickson, A. G., and Clegg, S. L. (2022). Chemical speciation models based upon the Pitzer activity coefficient equations, including the propagation of uncertainties: Artificial seawater from 0 to 45 °C. Marine Chemistry 244, 104095. doi: 10.1016/j.marchem.2022.104095.
SCOR Working Group 145