Figure 11

Fig. 11. Mean values of the CO₂ mole fraction in dry air [xCO₂ (air)] as measured by laboratories "A" through "E" and "G" during the period of the intercomparison exercise where data from all six systems are available (June 7, 22:30 UTC to June 13, 12:30 UTC). Also shown is the standard deviation of all xCO₂ (air) data sets from their mean. The horizontal line represents the mean xCO₂ (air) value calculated from the means of profiles "B" through "E" for this limited period of time.