ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-5-1125-2005 The aerosol-climate model ECHAM5-HAM Stier P. 1 Feichter J. 1 Kinne S. 1 Kloster S. 1 Vignati E. 2 Wilson J. 2 Ganzeveld L. 3 Tegen I. 4 Werner M. 4 Balkanski Y. 5 Schulz M. 5 Boucher O. 6 Minikin A. 7 Petzold A. 7 Max Planck Institute for Meteorology, Hamburg, Germany Institute for the Environment and Sustainability, European Commission Joint Research Centre, Ispra, Italy Max Planck Institute for Chemistry, Mainz, Germany Max Planck Institute for Biogeochemistry, Jena, Germany Laboratoire des Sciences du Climat et de l’Environnement, Gif-sur-Yvette, France CNRS, USTL, Villeneuve d’Ascq, France German Aerospace Agency DLR, Oberpfaffenhofen, Germany 31 03 2005 5 4 1125 1156 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/5/1125/2005/acp-5-1125-2005.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/5/1125/2005/acp-5-1125-2005.pdf

The aerosol-climate modelling system ECHAM5-HAM is introduced. It is based on a flexible microphysical approach and, as the number of externally imposed parameters is minimised, allows the application in a wide range of climate regimes. ECHAM5-HAM predicts the evolution of an ensemble of microphysically interacting internally- and externally-mixed aerosol populations as well as their size-distribution and composition. The size-distribution is represented by a superposition of log-normal modes. In the current setup, the major global aerosol compounds sulfate (SU), black carbon (BC), particulate organic matter (POM), sea salt (SS), and mineral dust (DU) are included. The simulated global annual mean aerosol burdens (lifetimes) for the year 2000 are for SU: 0.80 Tg(S) (3.9 days), for BC: 0.11 Tg (5.4 days), for POM: 0.99 Tg (5.4 days), for SS: 10.5 Tg (0.8 days), and for DU: 8.28 Tg (4.6 days). An extensive evaluation with in-situ and remote sensing measurements underscores that the model results are generally in good agreement with observations of the global aerosol system. The simulated global annual mean aerosol optical depth (AOD) is with 0.14 in excellent agreement with an estimate derived from AERONET measurements (0.14) and a composite derived from MODIS-MISR satellite retrievals (0.16). Regionally, the deviations are not negligible. However, the main patterns of AOD attributable to anthropogenic activity are reproduced.