Modeling of particle size distribution and its influence on the radiative properties of mineral dust aerosol
Article first published online: 21 SEP 2012
Copyright 1996 by the American Geophysical Union.
Journal of Geophysical Research: Atmospheres (1984–2012)
Volume 101, Issue D14, pages 19237–19244, 27 August 1996
How to Cite
1996), Modeling of particle size distribution and its influence on the radiative properties of mineral dust aerosol, J. Geophys. Res., 101(D14), 19237–19244, doi:10.1029/95JD03610., and (
- Issue published online: 21 SEP 2012
- Article first published online: 21 SEP 2012
- Manuscript Accepted: 10 NOV 1995
- Manuscript Received: 30 MAR 1995
The radiative parameters of mineral aerosols are strongly dependent on particle size. Therefore explicit modeling of particle size distribution is needed to calculate the radiative effects and the climate impact of mineral dust. We describe a parameterization of the global mineral aerosol size distribution in a transport model using eight size classes between 0.1 and 10 μm. The model prescribes the initial size distribution using soil texture data and aerosol size measurements close to the ground. During transport, the size distribution changes as larger particles settle out faster than smaller particles. Results of Mie scattering calculations of radiative parameters (extinction efficiency, single scattering albedo, asymmetry parameter) of mineral dust are shown at wavelengths between 0.3 and 30 μm for effective particle radii between 0.1 and 10 μm. Also included are radiative properties (reflection, absorption, transmission) calculated for a dust optical thickness of 0.1. Preliminary studies with the Goddard Institute for Space Studies (GISS) general circulation model (GCM), using two particle size modes, show regional changes in radiative flux at the top of the atmosphere as large as +15 W m−2 at solar and +5 W m−2 at thermal wavelengths in the annual mean, indicating that dust forcing is an important factor in the global radiation budget.