Atmospheric Chemistry and Physics www.atmos-chem-phys.net 1680-7316 1680-7324 5 9 2005 10.5194/acp-5-2431-2005 http://www.atmos-chem-phys.net/5/2431/2005/ http://www.atmos-chem-phys.net/5/2431/2005/acp-5-2431-2005.html http://www.atmos-chem-phys.net/5/2431/2005/acp-5-2431-2005.pdf 2431 2460 2005-09-21 Inverse modelling of national and European CH₄ emissions using the atmospheric zoom model TM5 P. Bergamaschi M. Krol F. Dentener A. Vermeulen F. Meinhardt R. Graul M. Ramonet W. Peters E. J. Dlugokencky European Commission Joint Research Centre, Ispra, Italy Institute for Marine and Atmospheric Research, Utrecht, Netherlands Netherlands Energy Research Foundation (ECN), Petten, Netherlands Umweltbundesamt, Messstelle Schauinsland, Kirchzarten, Germany Laboratoire des Sciences du Climat et de l’Environment (LSCE), Gif sur Yvette, France NOAA Climate Monitoring and Diagnostics Laboratory, Boulder, CO, USA A synthesis inversion based on the atmospheric zoom model TM5 is used to derive top-down estimates of CH₄ emissions from individual European countries for the year 2001. We employ a model zoom over Europe with 1&deg; &times; 1&deg; resolution that is two-way nested into the global model domain (with resolution of 6&deg; &times; 4&deg;. This approach ensures consistent boundary conditions for the zoom domain and thus European top-down estimates consistent with global CH₄ observations. The TM5 model, driven by ECMWF analyses, simulates synoptic scale events at most European and global sites fairly well, and the use of high-frequency observations allows exploiting the information content of individual synoptic events. A detailed source attribution is presented for a comprehensive set of 56 monitoring sites, assigning the atmospheric signal to the emissions of individual European countries and larger global regions. <P style="line-height: 20px;"> The available observational data put significant constraints on emissions from different regions. Within Europe, in particular several Western European countries are well constrained. The inversion results suggest up to 50-90% higher anthropogenic CH₄ emissions in 2001 for Germany, France and UK compared to reported UNFCCC values (EEA, 2003). A recent revision of the German inventory, however, resulted in an increase of reported CH₄ emissions by 68.5% (EEA, 2004), being now in very good agreement with our top-down estimate. The top-down estimate for Finland is distinctly smaller than the a priori estimate, suggesting much smaller CH₄ emissions from Finnish wetlands than derived from the bottom-up inventory. The EU-15 totals are relatively close to UNFCCC values (within 4-30%) and appear very robust for different inversion scenarios.