Table 2.
Offsets (in situ – flask) between continuous in situ and NOAA/GMD flask measurements. CO2 offsets are reported in μmol mol−1, CH4 and CO are reported in nmol mol−1. Continuous in situ CO is only measured at MSH. The average uncertainty column for each gas indicates the 1σ uncertainty (summed in quadrature over flask uncertainty, in situ uncertainty, and atmospheric variability over the hour) averaged over the flask samples. See text for discussion.
| Site | Number of flask samples | CO2 mean offset | CO2 median offset | CO2 standard deviation of offsets | CO2 mean unc. | CH4 mean offset | CH4 median offset | CH4 standard of offsets | CH4 mean unc. | CO mean offset | CO median offset | CO standard deviation of offsets | CO mean unc. |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MSH | 163 | 0.02 | −0.02 | 0.65 | 0.43 | −0.2 | −0.2 | 2.3 | 2.1 | −9.0 | −8.2 | 5.9 | 6.0 |
| LEW | 315 | 0.01 | −0.07 | 0.88 | 0.68 | 1.1 | 0.4 | 8.4 | 7.8 | - | - | - | - |
| TMD | 80 | 0.17 | 0.15 | 0.51 | 0.69 | 0.0 | 0.5 | 5.5 | 5.2 | - | - | - | - |
| NEB | 32 | −0.09 | 0.08 | 0.75 | 1.02 | −0.5 | 0.6 | 6.8 | 13.4 | - | - | - | - |
| NWB | 17 | −0.014 | 0.02 | 0.73 | 0.99 | −5.5 | −1.7 | 9.8 | 8.3 | - | - | - | - |