Invisible aerosol particles affect air quality and the climate

Professor of Atmospheric Science and Physics Katrianne Lehtipalo investigates the formation pathways and properties of the smallest particles in our atmosphere. This knowledge aids in the understanding of the effects of particles on air quality and their role in the global climate system.

What are your research topics?

My group investigates the physical properties of aerosol particles, or fine particles, including their concentration, size, charge distribution and optical properties in various environments. Through field measurements and laboratory experiments, we aim to determine how aerosol particles are formed and transformed in the air as a result of various chemical and physical processes. 

Picture the diameter of a human hair and divide it by 50,000. That is the size of the smallest aerosol particles immediately after their formation. We are investigating and testing the suitability of various measuring techniques especially for the study of these smallest particles, with the aim of improving the reliability and comparability of measurements. 

Where and how does the topic of your research have an impact?

Aerosol particles affect both air quality and the global climate. My research helps to understand particle properties in different environments and, consequently, their potential sources and effects. 

With the help of standardized measuring techniques, observations made in different environments can be compared and combined into a broader picture.

What is particularly inspiring in your field right now?

Novel measuring techniques help us continuously learn more about the mechanisms of particle formation and the gases that affect them. The smallest particles are found almost everywhere, both indoors and outdoors. This means that chemical reactions occur in the air, which initiate the chain reaction that results in the formation of particles. 

As yet, there is not enough information on the health effects of ultrafine particles, meaning particles of less than 100 nanometres in size. This is why it is important to investigate their sources, properties and occurrence in the air.