Daily offset correction for CO. Difference between the uncorrected measured CO value of the daily target tank and the known tank value for each site, for 2014 and 2015. Site numbers are indicated on each graph. This value was used as an offset correction to the atmospheric data. Dashed lines are ±2 ppb and ±5 ppb CO. Site 01 had an additional tank tank with known CH₄ as shown by the blue line, the extra tank at Site 02 was only characterized for CO₂ so there is only one target tank for CO at site 02. DOI: https://doi.org/10.1525/elementa.140.f5