Dr. Christian GEORGE (Ph. D. in the field of Physical-Chemistry - 1993, Habilitation in Chemistry - 1999, University Louis Pasteur - Strasbourg) has been active in the field of atmospheric chemistry and/or physical chemistry over the last decade. He acted as research scientist at the Fraunhofer Institute ITA at Hanover (Germany), at the CNRS Centre for Surface Geochemistry at Strasbourg (France) and now at CNRS-IRCELYON (France). Especially, he actively participated to projects focused on understanding multiphase transformation in the atmosphere.