Effects of Saharan dust and dry air on clouds and precipitation

Qilong Min
SUNY Albany

Abstract:

Dusts are a significant climate forcing due to their direct effects on scattering and absorption of solar and thermal radiation as well as indirect effects on clouds and precipitation. There are inconsistent results of aerosol indirect effects on clouds and lack of direct evidence that reveal the impacts of dusts on rainfall internal structures. We utilize multi-sensors on multi-platforms to investigate Sahara dust layer impact on cloud and precipitation over Atlantic Ocean, with focusing on microphysical processes of dust-cloud interaction. We found that dusts suppress the precipitation and reduce the latent heat release in high altitudes, resulting more suspended clouds. Strong convection in rainy clouds play a very important role in transporting Sahara dust particles from lower layer to upper layer of tropical atmosphere. Aerosol indirect effects are significantly altitude-dependent for different convection strengths.