The Atmospheric Chemistry Division focuses its research on fog and aerosol chemistry. Fog is characterized as a cloud lying close to the ground, in which visibility is less than 1,000 meters. Its occurrence is linked to specific local conditions, which significantly influence how long this phenomenon persists in the lower atmospheric layers.
This residence time and the chemical composition of the surrounding air masses determine the concentrations of substances in the fog. High concentrations are primarily observed for the main components—sulfate, nitrate, and ammonium—as well as for trace elements such as Al, Pb, Cu, and Zn, and for particles such as soot. These concentrations of substances frequently lead to damage to vegetation—for example, due to high sulfate levels—or to respiratory diseases (caused by respirable particles). The human and ecotoxicological effects of the fog are thus inherent.
Aerosols are defined as a suspension of solid or liquid particles in a gaseous phase. Aerosol particles originate from various emission sources and are released through both natural processes and human activities. Because of their short residence time in the atmosphere, pollution levels in a region depend heavily on local conditions, such as emission sources, the influence of long-range transport, and local sinks. Particles in the atmosphere occur in different size fractions and chemical compositions. They affect human health and interact with materials and ecosystems. They also have direct and indirect impacts on the climate.
