Atmospheric aerosol-cloud-climate interactions (e.g. particle oxidation and photosensitization, secondary aerosol and biogenic particle formation, molecular composition-, phase-, acidity- and structure- changes, heterogeneous ice nucleation ...) are fundamental processes in the atmosphere. Despite the importance of these processes in energy transfer, cloud dynamics, precipitation formation, and hence in climate change, little is known about the molecular mechanism and the respective contribution of different structural and chemical surface properties of the atmospheric aerosols and ice nuclei controlling these processes in the atmosphere. For Example, 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, shape, and surface properties makes it difficult to understand and parameterize their microphysical and hence radiative properties.
Fundamental understanding of the cloud dynamics and aerosol properties, which play the major role in the climate system, will require the understanding of gas-, water-, and ice-aerosol surface interactions. To advance our knowledge about atmospheric processes, this session aims to bring together two research areas, namely (1) Atmospheric Surface Science (ASS) and (2) Ice particles (IP) and Ice Nucleating Particles (INP):
(1) ASS is concerned with the experimental and theoretical approaches investigating atmospheric interactions as well as ice nucleation processes “on the molecular level”. The goal is to fill the gap between the large scale atmospheric processes and gas-, water-, and ice- interactions with atmospherically relevant mineral and biological surfaces.
(2) IP and INP are concerned with the laboratory examination, on a fundamental level, trying to understand the nucleation processes and characterizing IP and INP in the atmosphere.

- Solicited talk_1: "The Portable Ice Nucleation Experiment chamber (PINE): laboratory characterization and field test for its semi-automated ice-nucleating particle measurements in the Southern Great Plains".
Speaker: Naruki Hiranuma, West Texas A&M University, USA.