Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 6 4 2006 10.5194/acpd-6-6853-2006 http://www.atmos-chem-phys-discuss.net/6/6853/2006/ http://www.atmos-chem-phys-discuss.net/6/6853/2006/acpd-6-6853-2006.html http://www.atmos-chem-phys-discuss.net/6/6853/2006/acpd-6-6853-2006.pdf 6853 6901 2006-07-24 Technical Note: an implementation of the dry removal processes DRY DEPosition and SEDImentation in the Modular Earth Submodel System (MESSy) A. Kerkweg J. Buchholz L. Ganzeveld A. Pozzer H. Tost P. Jöckel Air Chemistry Department, Max-Planck Institute of Chemistry, P.O. Box 3060, 55020 Mainz, Germany We present the submodels DRYDEP and SEDI for the Modular Earth Submodel System (MESSy). Gas phase and aerosol dry deposition are calculated within DRYDEP, whereas SEDI deals with aerosol particle sedimentation. Dry deposition velocities depend on the near-surface turbulence and the physical and chemical properties of the surface cover (e.g. the roughness length, soil pH or leaf stomatal exchange). The dry deposition algorithm used in DRYDEP is based on the big leaf approach and is described in detail within this Technical Note. The sedimentation submodel SEDI contains two sedimentation schemes: a simple upwind zeroth order scheme and a first order approach.