Sensitivity of the total anthropogenic aerosol effect to the treatment of rain in a global climate model
Article first published online: 17 JAN 2009
Copyright 2009 by the American Geophysical Union.
Geophysical Research Letters
Volume 36, Issue 2, January 2009
How to Cite
2009), Sensitivity of the total anthropogenic aerosol effect to the treatment of rain in a global climate model, Geophys. Res. Lett., 36, L02805, doi:10.1029/2008GL035796., and (
- Issue published online: 17 JAN 2009
- Article first published online: 17 JAN 2009
- Manuscript Accepted: 2 DEC 2008
- Manuscript Revised: 26 NOV 2008
- Manuscript Received: 25 AUG 2008
- rain drop distribution;
- anthropogenic aerosol effect;
- global modelling
 This study investigates the sensitivity of the total anthropogenic aerosol effect to the treatment of rain within the global climate model (GCM) ECHAM5. A comparison between a prognostic (rain is stored within the atmosphere) and a diagnostic rain scheme (rain is precipitated out within one model time step) is conducted. Furthermore, the shape of the rain drop distribution within the prognostic rain scheme is varied. The prognostic rain scheme shifts the emphasis of the rain production process from autoconversion to accretion in better agreement with observations. Since the parameterization of the accretion process is independent of the cloud droplet number concentration, the total anthropogenic aerosol effect decreased by 0.5 to 0.9 Wm−2. Varying the rain drop distribution has a smaller influence on the total anthropogenic aerosol effect, changing it by 0.2 to 0.3 Wm−2.