Cold clouds (mixed-phase and ice) play an important role in the Earth’s radiation budget because of their high temporal and spatial coverage and their interaction with long wave and short wave radiation. Yet, the variability and complexity of their macro- and microphysical properties, a consequence of intricate ice particle nucleation, secondary ice production and growth processes, makes their study extremely challenging. As a result, large uncertainties still exist in our understanding of cold cloud processes, their radiative effects, and their interaction with their environment (in particular, aerosols).
This session aims to advance our comprehension of cold clouds by bringing observation- and modelling-based research together. A diversity of research topics shall be covered, highlighting recent advances in cloud observation techniques, modelling and subsequent process studies:
(1) Airborne, space borne, ground- or laboratory-based measurements and their derived products (e.g. retrievals), which are useful to characterise cloud properties like extent, emissivity, or crystal size distributions, to clarify formation mechanisms, and to provide climatologies.
(2) Process-based, regional and global model simulations that employ observations for better representation of cold cloud microphysical properties and radiative forcing under both current and future climate.
The synthesis of these approaches can uniquely answer questions regarding dynamical influence on cloud formation, life cycle, coverage, microphysical and radiative properties, crystal shapes, sizes and variability of ice particles in mixed-phase as well as ice clouds. Joint observation-modelling contributions are therefore particularly encouraged.