Global CO2fluxes inferred from surface air-sample measurements and from TCCON retrievals of the CO2 total column

• Published in: Geophysical research letters Vol. 38; no. 24
• Main Authors: Chevallier, F., Deutscher, N. M., Conway, T. J., Ciais, P., Ciattaglia, L., Dohe, S., Fröhlich, M., Gomez-Pelaez, A. J., Griffith, D., Hase, F., Haszpra, L., Krummel, P., Kyrö, E., Labuschagne, C., Langenfelds, R., Machida, T., Maignan, F., Matsueda, H., Morino, I., Notholt, J., Ramonet, M., Sawa, Y., Schmidt, M., Sherlock, V., Steele, P., Strong, K., Sussmann, R., Wennberg, P., Wofsy, S., Worthy, D., Wunch, D., Zimnoch, M.
• Format: Journal Article
• Language: English
• Published: Blackwell Publishing Ltd 28.12.2011
• Subjects: atmospheric inversion; CO2 fluxes; data assimilation; TCCON
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2011GL049899

We present the first estimate of the global distribution of CO2surface fluxes from 14 stations of the Total Carbon Column Observing Network (TCCON). The evaluation of this inversion is based on 1) comparison with the fluxes from a classical inversion of surface air‐sample‐measurements, and 2) comparison of CO2mixing ratios calculated from the inverted fluxes with independent aircraft measurements made during the two years analyzed here, 2009 and 2010. The former test shows similar seasonal cycles in the northern hemisphere and consistent regional carbon budgets between inversions from the two datasets, even though the TCCON inversion appears to be less precise than the classical inversion. The latter test confirms that the TCCON inversion has improved the quality (i.e., reduced the uncertainty) of the surface fluxes compared to the assumed or prior fluxes. The consistency between the surface‐air‐sample‐based and the TCCON‐based inversions despite remaining flaws in transport models opens the possibility of increased accuracy and robustness of flux inversions based on the combination of both data sources and confirms the usefulness of space‐borne monitoring of the CO2 column. Key Points Consistent seasonal cycle inferred from XCO2 and from pointwise observations The TCCON inversion improves the quality of the prior fluxes Our study experimentally confirms the usefulness of space‐borne CO2 monitoring