The effects of mineral dust particles, aerosol regeneration and ice nucleation parameterizations on clouds and precipitation 1Energy, Environment and Water Research Center, The Cyprus Institute, Nicosia, Cyprus
12 Oct 2012
2National Center for Atmospheric Research, Boulder, CO, USA
3Tel Aviv University, Tel Aviv, Israel
*Weizmann Institute of Science, Rehovot, Israel
Received: 07 Feb 2012 – Published in Atmos. Chem. Phys. Discuss.: 27 Mar 2012Abstract. This study focuses on the effects of aerosol particles on the formation of
convective clouds and precipitation in the Eastern Mediterranean Sea, with a
special emphasis on the role of mineral dust particles in these processes. We
used a new detailed numerical cloud microphysics scheme that has been
implemented in the Weather Research and Forecast (WRF) model in order to
study aerosol–cloud interaction in 3-D configuration based on
1° × 1° resolution reanalysis meteorological data.
Using a number of sensitivity studies, we tested the contribution of mineral
dust particles and different ice nucleation parameterizations to
precipitation development. In this study we also investigated the importance
of recycled (regenerated) aerosols that had been released to the atmosphere
following the evaporation of cloud droplets.
Revised: 30 Aug 2012 – Accepted: 05 Sep 2012 – Published: 12 Oct 2012
The results showed that increased aerosol concentration due to the presence
of mineral dust enhanced the formation of ice crystals. The dynamic
evolution of the cloud system sets the time periods and regions in which
heavy or light precipitation occurred in the domain. The precipitation rate,
the time and duration of precipitation were affected by the aerosol
properties only at small spatial scales (with areas of about 20 km2).
Changes of the ice nucleation scheme from ice supersaturation-dependent
parameterization to a recent approach of aerosol concentration and
temperature-dependent parameterization modified the ice crystals
concentrations but did not affect the total precipitation in the domain.
Aerosol regeneration modified the concentration of cloud droplets at cloud
base by dynamic recirculation of the aerosols but also had only a minor
effect on precipitation.
The major conclusion from this study is that the effect of mineral dust
particles on clouds and total precipitation is limited by the properties of
the atmospheric dynamics and the only effect of aerosol on precipitation may
come from significant increase in the concentration of accumulation mode
aerosols. In addition, the presence of mineral dust had a much smaller effect
on the total precipitation than on its spatial distribution.
Citation: Teller, A., Xue, L., and Levin, Z.: The effects of mineral dust particles, aerosol regeneration and ice nucleation parameterizations on clouds and precipitation, Atmos. Chem. Phys., 12, 9303-9320, doi:10.5194/acp-12-9303-2012, 2012.