Tröpfchenkernen

Tröpfchenkernen refers to the process of droplet nucleation, a fundamental phenomenon in phase transitions, particularly in the formation of liquids from a gaseous state or the creation of aerosols. It is a crucial step in cloud formation, condensation, and the generation of fine particles. The process involves the spontaneous formation of tiny, stable liquid droplets from a supersaturated vapor phase.

This nucleation typically occurs around existing microscopic particles in the atmosphere, known as condensation nuclei. Without these nuclei, the vapor would need to reach extremely high levels of supersaturation for homogeneous nucleation to occur, which is a much rarer event. Heterogeneous nucleation, facilitated by these nuclei, requires lower supersaturation levels and is therefore the dominant mechanism for droplet formation in most natural environments.

The size and chemical composition of the condensation nuclei play a significant role in determining the supersaturation required for nucleation. Water-soluble particles, such as salts and sulfates, tend to be more effective condensation nuclei than insoluble particles. The rate of droplet growth after nucleation is influenced by factors like the availability of water vapor, temperature, and the presence of other atmospheric constituents. Understanding droplet nucleation is essential for various scientific disciplines, including meteorology, atmospheric chemistry, and aerosol science.