nECS OA_Figshare.xlsx
The DIC was measured by acid extraction with infrared CO2 detection (AS-C3, Apollo SciTech Inc., USA), and the TA was determined by open-cell Gran acidimetric titration (AS-ALK2, Apollo SciTech Inc., USA). The uncertainties of measurements were evaluated daily using certified reference materials for seawater provided by the Scripps Institution of Oceanography (San Diego, USA). The DIC and TA measurements had precisions of approximately ±1.5 and ±2 μmol kg–1, respectively.
The seawater CaCO3 saturation state for aragonite (Ωarag) was calculated with CO2SYS program version 2.1 using salinity, temperature, depth, phosphate, silicate, TA, and DIC data. The carbonic acid dissociation constants of Mehrbach et al. (1973), as refit by Dickson and Millero (1987), were used to determine Ωarag. The uncertainty in the estimation of Ωarag was approximately ±0.02.