M05 - Aerosol-cloud session

Convenor: Ottmar Möhler
Co-Convenors: Greg McFarquhar, Yan Yin  

Aerosols from different sources and with a variety of chemical compositions and mixing states are key players in the formation and evolution of atmospheric liquid, mixed-phase and ice clouds. Depending on their size, chemical composition, phase state, and morphology, aerosol particles act as cloud condensation nuclei or ice nucleating particles (INPs). The latter constitute only a very minor fraction of atmospheric aerosol particles, therefore are very difficult to measure and to quantify, but very often initiate the formation of precipitation by primary ice nucleation followed by a cascade of secondary ice processes. Many underlying processes of cloud condensation nucleation, ice nucleation and ice multiplication are still only poorly understood. Improved formulations of aerosol microphysics in models are essential to quantify and predict the weather and climate impact of aerosols from both natural and anthropogenic sources like sea spray, soil dust, organic or biomass burning aerosols.

This session welcomes contributions on aerosol-cloud interactions for both freshly emitted and chemically processed aerosols, including field and laboratory measurements of CCN, INPs, ice nucleation and ice multiplication, ground-based, remote sensing or aircraft cloud measurements, description of new techniques and instruments, parameterizations of aerosol-cloud processes, theoretical developments and modeling studies at all scales.