Invited Presentation: Physical mechanisms of cloud-aerosol interaction at different scales

Different aspects of aerosol effects on warm and cold microphysics of clouds are discussed. A review of recent theoretical studies and numerical simulations is presented. It is shown that large CCN are responsible for formation of rain, while small CCN are responsible for formation of super cooled water at high levels,for high ice crystal concentration in anvils of deep convective clouds and foster hail formation. It is shown that soluble aerosols containing insoluble part can play a crucial role in formation of cirrus clouds. Effects of CCN on precipitation formation depend on environmental conditions such as humidity, wind shear etc. Mechanisms of CCN on cloud systems differ from those on isolated clouds. Examples of aerosol effects on isolated clouds, cloud systems and tropical cyclones are presented.