Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 5 2 2005 10.5194/acpd-5-1647-2005 http://www.atmos-chem-phys-discuss.net/5/1647/2005/ http://www.atmos-chem-phys-discuss.net/5/1647/2005/acpd-5-1647-2005.html http://www.atmos-chem-phys-discuss.net/5/1647/2005/acpd-5-1647-2005.pdf 1647 1678 2005-03-18 Daily CO2 flux estimates over Europe from continuous atmospheric measurements: 1, inverse methodology P. Peylin P. J. Rayner P. Bousquet C. Carouge F. Hourdin P. Heinrich P. Ciais AEROCARB contributors Laboratoire de Biogéochimie isotopique, CNRS-UPMC-INRA, Paris, France CSIRO Atmospheric Research, Aspendale, Victoria, Australia Laboratoire des Sciences du Climat et de l’Environnement, CEA, Gif-sur-Yvette, France Laboratoire de Météorologie Dynamique, CNRS, Paris, France Laboratoire DASE/LDG, CEA, Bruyeres-le-Chatel, France Experimentalists that contributed to the atmospheric measurements: A. Adolphsen, F. Apadula, R. Graul, L. Haszpra, M. Ramonet, R. Santaguida, M. Schmidt This paper presents a method for inferring trace gas fluxes at high temporal and spatial resolution from atmospheric concentration measurements. The method is designed for regional applications and for use in intensive campaigns. We apply the method to a one month inversion 5 of fluxes over Europe. We show that the information added by the measurements depends critically on the smoothness constraint assumed among the source components. We show that the initial condition affects the inversion for 20 days, provided one has enough observing sites to constrain regional fluxes. We show that the impact of the far-field fluxes grows throughout the inversion and hence a 10 reasonable global flux field is a prerequisite for a regional inversion.