Figure 4

Fig. 4. Results from the check of the CO₂ calibration performance: Shown are the observed deviations from the concentrations of all measured NOAA/CMDL CO₂ standards. Pink crosses indicate the concentrations of the standards used in the exercise. The legend gives details of the nominal concentrations used for calibration. Also shown is the range of measured xCO₂ during the whole intercomparison.