Aerosol Physics and Chemisty
An aerosol is a suspension of fine particles in a gas, usually air, and is generally taken to include both solid and liquid particles with dimensions ranging from a few nanometers up to around 100 micrometers in diameter. Aerosol science is the study of the physics and chemistry of aerosol properties and behavior in the atmosphere and in technical processes involving particulate matter such as combustion. This includes techniques of generating particles of nanometer and micrometer dimensions, size classification and measurement of transport and deposition properties, chemical properties of aerosol particles in the atmosphere and in industry, as well as health effects. In our group, the studies of the aerosol physical and chemical properties are focused on aerosol-cloud interactions and are carried out in-situ and in the laboratory.
The knowledge of the aerosol physical properties such like particle size, number, morphology and shape represents the basis for the understanding of the role of aerosol particles in atmospheric processes and climate - and explicitly in the field of cloud microphysics. We investigate the aerosol physical properties experimentally deploying state-of-the-art analytical techniques, as well as theoretically using atmospheric models of different scales.
Knowledge of an atmospheric particle’s chemical composition is of importance as it determines the optical properties of particles and affects atmospheric chemistry in the gas as well as in the particulate phase. Moreover, the aerosol chemical composition influences the ability of particles to act as cloud condensation nuclei (CCN) or ice nucleating particles (INPs). For instance, while some particles (such as minerals) do not make very good CCN, they act as very good IN in colder parts of the atmosphere. In order to better understand these aerosol-cloud interactions our group carries out measurements of the aerosol chemical composition using aerosol mass spectrometry. Two different types of instruments are deployed: a single particle mass spectrometer ATOFMS providing semi-quantitative information on individual refractory and non-refractory particles, and a bulk particle mass spectrometer with the ability to quantitatively characterize the size-resolved composition of the aerosol.
Furthermore, the study of the physical and chemical properties of combustion particles is another research topic of our group, linking anthropogenic soot sources to the atmospheric aerosol.