Ute Karstens (1), Ingeborg Levin (2), Camilla Geels (3), Sander Houweling (4), Rolf Neubert (5), Philippe Peylin (6), Christian Rödenbeck (1), Kazimierz Rozanski (7)
(1) Max-Planck-Institute for Biogeochemistry
(2) Institut für Umweltphysik, Universität Heidelberg
(3) National Environmental Research Institute (NERI)
(4) National Institute for Space Research (SRON)
(5) Centre for Isotope Research, Groningen University
(6) Laboratoire des Sciences du Climat et de l'Environnement (LSCE)
(7) AGH University of Science and Technology
(1) Hans-Knöll-Str. 10, 07745 Jena, Germany
(2) Im Neuenheimer Feld 229, 69120 Heidelberg, Gemany
(3) Frederiksborgvej 399, 4000 Roskilde, Denmark
(4) Princetonplein 5, 3584 CC Utrecht, The Netherlands
(5) Nijenborgh 4, 9747 AG Groningen, The Netherlands
(6) UMR CEA-CNRS, Orme des Merisiers, 91191 Gif-sur-Yvette, France
(7) Al. Mickiewicza 30, 30-059 Krakow, Poland
fossil fuel CO 2, transport model, emissions inventory
Estimates of continental carbon fluxes from inversions of atmospheric CO 2 measurements typically require a separation of the contribution from fossil fuel emissions in the atmospheric CO 2 signal. In order to assess the uncertainties related to the use of different transport models and different emissions inventories to estimate this fossil fuel CO 2 component, respective model simulations are compared to measurements of radiocarbon-based fossil fuel CO 2 at several stations in Europe. 14CO 2 observations allow quantitative estimation of the fossil fuel component in atmospheric CO 2 because fossil fuels are free of 14C. Fossil fuel CO 2 concentra-tions were simulated by three global atmospheric transport models, which are all currently used in inversion studies, and, additionally, by two regional models in order to cover a wider range of horizontal and vertical resolutions. In all model simulations we used the same set of different emissions inventories, including commonly used annual maps as well as newly available hourly estimates of CO 2 emissions from fossil fuel combustion. The comparison of these model simulations with 14CO 2-based fossil fuel CO 2 observations allows us to assess uncertainties caused by the representation of transport in the different models but it also gives some indication of the potential improvements due to the new emissions estimates with high temporal resolution. For most stations the spread between models using the same emissions inventory is still much larger than the differences caused by the use of different inventories within the same model. This calls for further evaluation and improvement of the transport models before an independent verification of emissions inventories through this kind of comparison will be reliable.
updated by Yvonne Hofmann,