Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 5 4 2005 10.5194/acpd-5-4739-2005 http://www.atmos-chem-phys-discuss.net/5/4739/2005/ http://www.atmos-chem-phys-discuss.net/5/4739/2005/acpd-5-4739-2005.html http://www.atmos-chem-phys-discuss.net/5/4739/2005/acpd-5-4739-2005.pdf 4739 4799 2005-07-13 Technical note: The Lagrangian particle dispersion model FLEXPART version 6.2 A. Stohl C. Forster A. Frank P. Seibert G. Wotawa Norwegian Institute of Air Research, Kjeller, Norway Institute of Meteorology, University of Natural Resources and Applied Life Sciences, Vienna, Austria Preparatory Commission for the Comprehensive Nuclear Test Ban Treaty Organization, Vienna, Austria The Lagrangian particle dispersion model FLEXPART was originally (about 8 years ago) designed for calculating the long-range and mesoscale dispersion of air pollutants from point sources, such as after an accident in a nuclear power plant. In the meantime FLEXPART has evolved into a comprehensive tool for atmospheric transport modeling and analysis. Its application fields were extended from air pollution studies to other topics where atmospheric transport plays a role (e.g., exchange between the stratosphere and troposphere, or the global water cycle). It has evolved into a true community model that is now being used by at least 25 groups from 14 different countries and is seeing both operational and research applications. A user manual has been kept actual over the years and was distributed over an internet page along with the model's source code. However, so far there was no citeable description of FLEXPART. In this note we provide a description of FLEXPART's latest version (6.2).