B/Ca, δ¹¹B and calcifying fluid carbonate chemistry reconstruction of Porites sp. from Rotuma (RO2)

Samples were collected from two Porites sp. coral cores in the Southwestern Pacific, specifically at Rotuma Island (Fiji). Parameters measured in this study include boron stable isotope analysis (δ11B) and Boron/Calcium (B/Ca) ratios. The Rotuma coral core (RO2) provided 178 annual samples covering the period from 1821 to 1998 out of which 102 were analyzed for δ11B. δ11B measurements were conducted on NuPlasma II MC-ICP-MS and boron was concentrated using the micro-distillation (sublimation) method. B/Ca was originally analyzed in every to every second millimeter resolution, providing approximately bimonthly resolution, on Analytik Jena PlasmaQuant Elite ICP-MS. That data was annualized for this study and here it is attached in its annual resolution. The carbonate chemistry of the calcifying fluid was reconstructed using δ11B and B/Ca ratios yielding reconstructions of pHcf (calcifying fluid pH), pHsw (seawater pH), [CO3²] (carbonate ion concentration), DIC (dissolved inorganic carbon), and Ωcf (aragonite saturation state). Reconstructions of [CO3²], DIC and Ωcf were calculated using boronsysarag (DeCarlo et al., 2018;doi:10.5194/bg-15-2819-2018) and seacarb (Gattuso et al., 2021; https://cran.r-project.org/web/packages/seacarb/index.html) packages in R statistical software (R Core team, 2021; https://www.r-project.org/foundation/).