Comparison method: background selection and application of the kriging approach. Averaged CO₂, CH₄ and CO emission rates from the nine mass balance experiments (MBEs) i) when the emission rates were calculated by kriging the point fluxes (kriging_F_ijk) and ii) when they were calculated and integrated after interpolation of concentrations, pressure, temperature and perpendicular wind speed (kriging_CTPU). For both interpolation methods, backgrounds were defined iii) as linear regression (BG_linReg) and iv) as averages (BG_avg). Precision is the standard error of the mean at 95% CL. DOI: https://doi.org/10.1525/elementa.134.t1