Work package 1 - Revising the cloud scheme
Work package 2 - Contrails
Anthropogenic aerosols have an impact on cloud formation, cloud properties and their life times. Comparing those indirect aerosol effects on clouds, or the clouds themselves, in simulations and observations is hampered by changes in cloudiness due to air traffic.
A prerequisite for realistically simulating the cloud adjustment to aerosol-radiation interactions is a realistic representation of aerosol radiative properties in the model. The aim of work package 3 are new time-varying 3D distributions of cloud condensation nuclei (CCN) and aerosol radiative properties, which will be used in dedicated simulations with the ICON_GCM (global circulation model) and the high-resolved HD(CP)² model to analyze the cloud adjustment effects.
Work package 4 - Response of mixed-phase clouds to aerosol perturbations
Atmospheric aerosol particles influence cloud properties by acting as the seeds for cloud droplet and ice particle formation. Work package 4 uses the ICON_LEM to investigate how changes in the concentration of cloud condensing and ice nucleating particles affect the microphysical characteristics of mixed-phase clouds, which comprise both liquid droplets and ice particles.
The aerosol and CCN (cloud condensation nuclei) profiles derived from COSMO-MUSCAT as an input for ICON-LEM are evaluated using measurements from HD(CP)² supersites. Multiwavelength lidar is the main instrument for this purpose.
Work package 6 - Scale- and regime-dependency of cloud-aerosol relationships
Cloud observations from polar-orbiting satellites are used to investigate the scale- and regime dependency of cloud-aerosol relationships. The observed and modelled spatial and temporal distributions of cloud properties are analyzed by, e.g., the construction of probability density functions, also stratified with respect to meteorological parameters.
Work package 7 - Modelling and Observations
Work package 7 in particular works on the evaluation of the ICON-LES model, we compare the control run and perturbed simulations with observations.
Work package 8 - Detectability in observations