Atmospheric Chemistry and Physics Anthropogenic and forest fire pollution aerosol transported to the

Abstract. During the POLARCAT-France airborne measure-ment campaign in spring 2008, several pollution plumes transported from mid-latitude regions were encountered. The study presented here focuses on air masses from two differ-ent geographic origins (Europe and Asia) and from 2 differ-ent source types (anthropogenic pollution and forest fires). A first case study is dedicated to a European air mass, which was repeatedly sampled and analysed during three consec-utive days. Thereby, the evolution of the aerosol properties (size distributions, CO mixing ratio) is characterised and re-lated processes are discussed. In particular, the role of coag-ulation, condensation and cloud processing in the evolution of the Aitken and the accumulation mode particles are con-trasted. A second case study focuses on European air masse