Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 9 5 2009 10.5194/acpd-9-18511-2009 http://www.atmos-chem-phys-discuss.net/9/18511/2009/ http://www.atmos-chem-phys-discuss.net/9/18511/2009/acpd-9-18511-2009.html http://www.atmos-chem-phys-discuss.net/9/18511/2009/acpd-9-18511-2009.pdf 18511 18543 2009-09-09 Modeling the transport of very short-lived substances into the tropical upper troposphere and lower stratosphere J. Aschmann jaschman@iup.physik.uni-bremen.de B. M. Sinnhuber E. L. Atlas S. M. Schauffler Institute of Environmental Physics, University of Bremen, Bremen, Germany Rosenstiel School of Marine and Atmospheric Science, University of Miami, USA National Center for Atmospheric Research, Boulder, Colorado, USA The transport of very short-lived substances into the tropical upper troposphere and lower stratosphere is investigated by a three-dimensional chemical transport model using archived convective updraft mass fluxes (or detrainment rates) from the European Centre for Medium-Range Weather Forecast's ERA-Interim reanalysis. Large-scale vertical velocities are calculated from diabatic heating rates. With this approach we explicitly model the large scale subsidence in the tropical troposphere with convection taking place in fast and isolated updraft events. The model calculations agree generally well with observations of bromoform and methyl iodide from aircraft campaigns and with ozone and water vapor from sonde and satellite observations. 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