Vaughan Phillips
Research in the Area of Clouds, Aerosols and Climate
A new parameterization of cloud droplet activation applicable to general circulation models
Author
Summary, in English
A new parameterization is proposed to link the droplet number concentration to the size distribution and chemical composition of aerosol and updraft velocity. Except for an empirical assumption of droplet growth, the parameterization is formulated almost entirely on first principles to allow for satisfactory performance under a variety of conditions. For a series of updraft velocity ranging from 0.03 to 10.0 m s(-1), the droplet number concentrations predicted with the parameterization are in good agreement with the detailed parcel model simulations with an average error of -4 +/- 26% (one standard deviation). The accuracy is comparable to or better than some existing parameterizations. The parameterization is able to account for the effects of droplet surface tension and mass accommodation coefficient on activation without adjusting the empirical parameter. These desirable attributes make the parameterization suitable for being used in the prognostic determination of the cloud droplet number concentration in general circulation models (GCMs).
Publishing year
2006
Language
English
Pages
1348-1356
Publication/Series
Journal of Atmospheric Sciences
Volume
63
Issue
4
Document type
Journal article
Publisher
Amer Meteorological Soc
Topic
- Physical Geography
Status
Published
ISBN/ISSN/Other
- ISSN: 1520-0469