SoMAS Research on Cloud Microphysics – Atmospheric Ice Formation featured in Physical Chemistry Chemical Physics
The prediction of the formation of ice crystals in the atmosphere presents one of the biggest challenges in the atmospheric sciences. Ice crystals will affect the properties of clouds with consequences for climate and the hydrological cycle and thus precipitation. In the atmosphere ice forms on pre-existing airborne particles, also called aerosols, which are present in sizes from a few nanometers to hundreds of micrometers. The physical and chemical properties of these aerosol particles govern the conditions under which ice can form. To improve our fundamental knowledge of atmospheric ice crystal formation, a novel experimental setup has been developed that allows to observe ice formation on the nanoscale. An environmental chamber, in the size of a poppy seed, that allows to simulate atmospheric conditions up to ~13 km in height, is implemented within an electron microscope. This approach allows to observe in situ and at high resolution how and where ice forms on nano- and micrometer sized aerosol particles, i.e. being witness of the birth of an embryonic ice crystal.