Ice particles in the atmosphere, both in cirrus and mixed-phase clouds, contribute to the largest uncertainty in interpretations of the Earth’s changing energy budget. Their large variability in number, size and shape makes it difficult to understand and parameterize their microphysical and hence radiative properties.

To advance our understanding of these clouds, this session aims to bring together two research areas, namely (1) 'Ice Clouds (IC)' and (2) 'Ice Nucleating Particles (INP)':

(1) 'Ice Clouds (IC)' are investigated with different approaches and methodologies: observations (ground based, airborne and spaceborne), modelling (process-based, regional and global) as well as radiative transfer and transport studies. We aim to gather contributions from all these aspects including dynamical influence on ice cloud formation, life cycle, coverage, microphysical and radiative properties, crystal shapes, sizes and variability of ice particles for mixed-phase as well as cirrus clouds.

(2) 'Ice Nucleating Particles (INP)' are examined in the laboratory on a fundamental level, trying to understand the nucleation processes. For characterizing INP in the atmosphere, their temperature dependent number concentrations are determined by ground based and aircraft measurements, and also remote sensing.

This session is intended to promote the exchange of knowledge between the different communities, and welcomes contributions from all topics mentioned above.

Just before the EGU, from 3rd to 6th April 2019, the Viennese colleagues Bernadett Weinzierl, Anne Kasper-Giebl and Hinrich Grothe will organize the 12th International Conference on Carbonaceous Particles in the Atmosphere (ICCPA) 2019, where ice nucleation will also be a highlighted topic: www.iccpa.net