ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-6-149-2006 The effect of systematic measurement errors on atmospheric CO<sub>2</sub> inversions: a quantitative assessment Rödenbeck C. 1 Conway T. J. 2 Langenfelds R. L. 3 Max Planck Institute for Biogeochemistry, Jena, Germany NOAA Climate Monitoring and Diagnostics Laboratory, Boulder CO, USA CSIRO Marine and Atmospheric Research, Australia 25 01 2006 6 1 149 161 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/6/149/2006/acp-6-149-2006.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/6/149/2006/acp-6-149-2006.pdf

Surface-atmosphere exchange fluxes of CO<sub>2</sub>, estimated by an interannual atmospheric transport inversion from atmospheric mixing ratio measurements, are affected by several sources of errors, one of which is experimental errors. Quantitative information about such measurement errors can be obtained from regular co-located measurements done by different laboratories or using different experimental techniques. The present quantitative assessment is based on intercomparison information from the CMDL and CSIRO atmospheric measurement programs. We show that the effects of systematic measurement errors on inversion results are very small compared to other errors in the flux estimation (as well as compared to signal variability). As a practical consequence, this assessment justifies the merging of data sets from different laboratories or different experimental techniques (flask and in-situ), if systematic differences (and their changes) are comparable to those considered here. This work also highlights the importance of regular intercomparison programs.