Atmospheric Chemistry and Physics www.atmos-chem-phys.net 1680-7316 1680-7324 8 14 2008 10.5194/acp-8-3963-2008 http://www.atmos-chem-phys.net/8/3963/2008/ http://www.atmos-chem-phys.net/8/3963/2008/acp-8-3963-2008.html http://www.atmos-chem-phys.net/8/3963/2008/acp-8-3963-2008.pdf 3963 3971 2008-07-24 Probing ETEX-II data set with inverse modelling M. Krysta monika.krysta@imag.fr M. Bocquet J. Brandt Université Paris-Est, CEREA, Research and Teaching Centre in Atmospheric Environment, Joint Laboratory École Nationale des Ponts et Chaussées/EDF R&D, 6–8 avenue Blaise Pascal, 77455 Champs sur Marne, France INRIA, Paris-Rocquencourt Research Centre, France Department of Atmospheric Environment, National Environmental Research Institute, Aarhus University, Frederiksborgvej 399, P.O. Box 358, 4000 Roskilde, Denmark currently at: Laboratoire Jean Kuntzmann, University of Grenoble, BP 53X, 38041 Grenoble cedex, France We give here an account on the results of source inversion of the ETEX-II experiment. Inversion has been performed with the maximum entropy method on the basis of non-zero measurements and in conjunction with a transport model POLAIR3D. The discrepancy scaling factor between the reconstructed and the true mass has been estimated to be equal to 7. The results contrast with the method's performance on the ETEX-I source. In the latter case its mass has been reconstructed with an accuracy exceeding 80%. The large value of the discrepancy factor for ETEX-II could be ascribed to modelling difficulties, possibly linked not to the transport model itself but rather to the quality of the measurements. Bellasio R., Bianconi R., Mosca S., Girardi F., Graziani G., and Klug W.: Simulation of the second ETEX release in the proximity of the source. Int. J. 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