Figure 5
Mean xc[CO32−] (μmol kg−1) versus atmospheric CO2 concentration (ppm) for the living cold-water coral (CWC) layer (σ0 = 27.35–27.65 kg m−3) observed (inset) and predicted. The inset shows the observed measurements and the grey shading accounts for the trend errors. The linear trend in the inset (green line, μmol kg−1 ppm−1) has a statistical p-value = 4.3 × 10–5. In the inset, the uncertainties in the mean properties are two times the standard error of the mean (i.e., 95% confidence interval), and the year of the cruise is represented in the upper x-axis. The predictions (dashed lines) are based on the linear rate of decrease for the observational period (green) and on the thermodynamic equilibrium trend (blue, Orr et al.10).
