Aerosol-Cloud Interactions: Insights from the East Mediterranean

This lecture provides an overview of aerosol-cloud interactions in warm and mixed-phase orographic clouds, focusing on studies conducted at Mt. Helmos in Greece. The instructor discusses the Cloud-Aerosol Interaction Studies in the Helmos background Troposphere (CALISHTO) project, which spanned from Fall 2001 to Winter 2022. The lecture highlights the use of in-situ measurements, remote sensing, and modeling to understand the sources of cloud condensation nuclei (CCN) and ice nuclei (IN) in the region. The instructor explains how boundary layer turbulence, vertical aerosol distributions, and meteorological conditions influence cloud microphysical states, including supersaturation and droplet/ice formation. The role of secondary ice processes in mixed-phase clouds is also examined, emphasizing their significance for precipitation formation. The lecture concludes with insights on how the integration of various observational techniques can enhance understanding of these complex atmospheric processes, which are crucial for improving climate models and predicting human impacts on climate.