Calculating chemical speciation, including the carbonate system and trace metal complexation, in natural waters of varying composition.
In conjunction with OCB2023, we will convene a hands-on tutorial for a new marine chemical speciation model MarChemSpec (Clegg et al., 2022a,b; Humphreys et al., 2022; OCB science feature) on June 15-16 (WHOI/hybrid). This model, which determines species concentrations from thermodynamic equilibrium constants and activity coefficients calculated using the Pitzer equations, can estimate:
*Acid-base speciation and pH (with uncertainties) in seawaters of all salinities, and in natural waters whose compositions differ from seawater stoichiometry
*Complexation of core GEOTRACES species (Fe, Zn, Cd, Cu, Al, Mn, Pb), plus Co and Ni, by inorganic anions
The model will be made freely available in the first half of 2023 as standalone executable programs, and also for Matlab, Python, and R. This tutorial will briefly chronicle the development and evolution of the model, highlight its scientific applications, and show how to use the modeling tools using practical examples. Note that participation in the tutorial will require a small amount of advance work to prepare (involving downloads and a short exercise).
Please indicate your interest in the tutorial (we will try to convene it in a hybrid format to enable virtual participation) by filling out this form. If you have Matlab, Python, and/or R skills and experience and can work both Mac and/or Windows platforms, we would appreciate having a small number of assistants to help us run the tutorial. We will provide a small honorarium for those who can help! Please indicate your interest in helping in this capacity on the form.
S. L. Clegg, 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. III. Seawater from the freezing point to 45 oC, Including acid-base equilibria. In press, Mar. Chem.
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. no. 104096, https://doi.org/10.1016/j.marchem.2022.104096.
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 oC. Mar. Chem. 244, art. no. 104095, https://doi.org/10.1016/j.marchem.2022.104095.