Final Activity Report Summary - WWLC (Weak Water vapour Lines Contribution to the absorption of atmospheric radiation) During 2007 and 2008, Boris Voronin continued his work on the project at the institute of atmospheric optics in the Siberian branch of the Russian Academy of Sciences (IAO SB RAS). In the Russian stage of the project Boris combined innovative knowledge on the high accuracy variational calculations of water vapour spectra, acquired by him while working in University College London (UCL), with the methodology and practical means of intricate asymmetric top molecule spectra analysis and atmospheric radiation transmittance calculations developed in IAO to successfully finish the project. Boris recommended himself as a competent, independent and enthusiastic researcher. For the project implementation Boris organised and managed a group of scientists belonging to different departments of IAO. The financial support from the Marie Curie Actions was decisive for the project implementation. Boris equipped his working place with powerful computers and modern software, which were necessary for the realisation of the intricate calculations required by the project. Following the project successful completion Boris intended to apply all this equipment in his further scientific activity, connected to international scientific cooperation with colleagues from UCL, from the Joseph Fourier University in Grenoble, from University of Science and Technology of China and other Institutions. Among the main results obtained by Boris and his UCL and IAO co-workers in the third stage of the project were: 1. generation of the HDO high accuracy synthetic spectrum involving highly excited upper rovibrational levels with J between 10 and 40; 2. evaluation of the H217O, H218O, and HDO halfwidths, necessary for atmospheric calculations; 3. further validation of the variational linelists using newly available experimental data and; finally 4. estimation of the total contribution, up to 4 %, of the absorption by weak water vapour lines to the radiative balance of the atmosphere. All these results contributed towards the complete and successful implementation of the project. The results that were obtained with the active participation of Boris Voronin were published in international scientific journals, namely in the Journal of Molecular Spectroscopy and the Journal of Chemical Physics. Several papers were prepared for publication in the Journal of Molecular Spectroscopy and in Atmospheric and Oceanic Optics. A separate paper was accepted for publication in the collective monograph 'Molecular spectroscopy and frequencies standard' in Russian. In addition, Boris Voronin made several oral and poster presentations at international conferences. These reports met positive appreciation and were recommended for publication in a special issue of the Journal of Molecular Spectroscopy. The Marie Curie fellowship clearly promoted Boris Voronin's scientific career. The fellow became the head of group of young scientists, including his own PhD student, that were working at IAO, whose scientific interests aimed at climate problems, molecular spectroscopy and molecular quantum mechanics. He became also member of the local committee and technical secretary of the 15th International Symposium on Atmospheric and Oceanic Optics and Atmospheric Physics, which was held from 22 to 29 June 2008 at Krasnoyarsk, Russia. He also executed the duties of the Head of Laboratory of Molecular Spectroscopy during three months. By the time of the project completion the stuff commission of IAO had recommended Boris for the position of senior researcher. Boris' activity during the project implementation promoted collaboration between the specialists working at IAO and their foreign colleagues in United Kingdom, France and China, which was to the benefit of all participating institutions. This collaboration was anticipated to continue in the future. The short term Boris' plan included the analysis of the HDO hot spectra in a wide Infrared (IR) spectral region with the participation of the English and German colleagues. In summary, it was estimated that innovative scientific experience and knowledge combined with strengthened international scientific collaboration, which resulted from the Marie Curie Action fellowship, would serve as the reliable basis for Boris Voronin's further steps in his scientific career.