%0 Journal Article %T The atmospheric chemistry box model CAABA/MECCA-3.0gmdd %A R. Sander %A A. Baumgaertner %A S. Gromov %A H. Harder %J Geoscientific Model Development Discussions %D 2011 %I Copernicus Publications %R 10.5194/gmdd-4-197-2011 %X We present version 3.0gmdd of the atmospheric chemistry box model CAABA/MECCA. In addition to a complete update of the rate coefficients to the most recent recommendations, a number of new features have been added: chemistry in multiple aerosol size bins; automatic multiple simulations reaching steady-state conditions; Monte-Carlo simulations with randomly varied rate coefficients within their experimental uncertainties; calculations along Lagrangian trajectories; mercury chemistry; more detailed isoprene chemistry; tagging of isotopically labeled species. Further changes have been implemented to make the code more user-friendly and to facilitate the analysis of the model results. Like earlier versions, CAABA/MECCA-3.0gmdd is a community model published under the GNU General Public License (GPL). %U http://www.geosci-model-dev-discuss.net/4/197/2011/gmdd-4-197-2011.pdf