Simon Clegg has just completed a visit of two and a half months to the University of Gothenburg, Sweden, where he worked with WG 145 Chair David Turner. Experimental work needed for the development of the chemical speciation model was planned, and the current “state of the science” Pitzer model of artificial seawater was assembled and the parameters checked. Our initial goal is to develop a metrologically traceable model of Tris/TrisH+ buffers in artificial seawaters, as a function of both salintiy and temperature. The planned experiments reflect this, and include solutions such as Tris/TrisH+ in NaCl(aq), H+/TrisH+/Cl- solutions, and Tris/TrisH+ in aqueous NaCl/Na2SO4, for example.

The large experimental effort will be shared between Andrew Dickson at Scripps Institution of Oceanography, and our colleagues at the national metrological institutes of Germany, France, and Japan, and at GEOMAR in Kiel (Germany).

We have recently learned of two new/recent projects that, while entirely independent of
our research, are closely related:

• Robert (Bob) Byrne at the University of South Florida, has a three year project entitled “Development of Spectrophotometric pH Measurement Capabilities in Estuaries” (supported by NSF).
• Wei-Jun Cai at the University of Delaware has been funded by NOAA to work on improving scientists’ ability to measure pH in dilute seawater (estuarine environments), and to evaluate the behaviour of different types of electrode. He will be collaborating with scientists at the National Institute of Standards and Technology.

We look forward to exchanging information (and collaborating, if possible) with both Bob and Wei-Jun, beginning with a web-based conference in December 2017.