ACPD Atmospheric Chemistry and Physics Discussions ACPD 1680-7375 Copernicus GmbH Göttingen, Germany 10.5194/acpd-2-2133-2002 Adjoint backtracking for the verification of the Comprehensive Test Ban Treaty Issartel J.-P. 1 2 Baverel J. 1 Ecole Nationale des Ponts et Chaussées, Centre d’Enseignement et de Recherche Eau, Ville, Environnement, Champs sur Marne, France previously at: Commissariat à l’Energie Atomique, DASE, Bruyères le Châtel, France 19 11 2002 2 6 2133 2150 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys-discuss.net/2/2133/2002/acpd-2-2133-2002.html The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/2/2133/2002/acpd-2-2133-2002.pdf

An international monitoring system is being built as a verification tool for the Comprehensive Test Ban Treaty. Forty stations will measure on a worldwide daily basis the concentration of radioactive noble gases. The paper introduces, by handling preliminary real data, a new approach of backtracking for the identification of sources after positive measurements. When several measurements are available the ambiguity about possible sources is reduced significantly. As an interesting side result it is shown that diffusion in the passive tracer dispersion equation is necessarily a self-adjoint operator.