Recent observations for ageing of organic and multi-component aerosols indicate that the coupling of gas- and particulate phase may be more important for microphysical and chemical properties of aerosols then previously thought. By definition aerosols invoke gas-phase and particulate phase. This fact contributes to the complexity (and scientific challenge) of aerosols as the formation and the chemical evolution of aerosols in the atmosphere are driven by chemical processes in gas- and particle phase and subsequent exchange of reaction products between both phases.

The session Aerosol Chemistry and Microphysics is aiming to present and to discuss the newest findings regarding chemical ageing of aerosols and its importance for atmospheric chemistry and climate.