Aerosols

Atmospheric aerosol particles are solid or liquid particles suspended in air. We are interested in processes that control formation, transformation and the removal of aerosol particles. These particles, which are often smaller than 1 micrometer in diameter, play an important part in Earth's radiation budget through the scattering of sunlight and through the interaction with clouds. Human activities, such as burning of fossil fuels and land use, change the properties of the aerosol and may therefore influence the climate. This can be either directly through an increase in aerosol number enhancing the aerosol-radiation interaction, and/or size or indirectly through the way the anthropogenic aerosols change the way clouds form. In addition, heterogeneous reactions on the aerosol particle surfaces or in the volume of liquid aerosol particles influences the atmospheric gas phase composition and chemistry. Furthermore, aerosols can be responsible for adverse health effects through inhalation.

To assess the role of aerosols in our environment and the influence by anthropogenic emissions requires an understanding of the life cycle and transport patterns for aerosol particles, their compositional evolution as well as a detailed knowledge of how cloud formation mechanisms depend on the properties of the pre-existing aerosols.

• Measurements of individual levitated aerosol particles
• Rutherford Backscattering Spectrometry (RBS) to probe the gas/aerosol particle interface 
• Thermodynamic modeling of the composition of liquid aerosol particles
• Liquid-liquid phase separation within aerosol particles
• Glassy aerosol particles and diffusion limitation
• Aerosols acting as ice nucleating particles
  
• Optical properties of liquid aerosol
• Vapor pressure of organic aerosol particles
• Stratospheric solar geoengineering
• Infectivity of viruses in expiratory aerosols