Aerosols in the future: What drives their formation and how can we develop new methods to investigate them?

The atmosphere is changing. Human activities have altered the composition of the air over the last century, but nowadays more and more emission regulations are imposed. What will the future atmosphere be like? And are human activities still influencing climate patterns and air quality? In our research group we focus on aerosols, tiny liquid, or solid particles suspended in air. They are a crucial component of the atmosphere. They can act as cloud condensation nuclei: without aerosol particles there would be no cloud droplets. And they can impact human health: Breathing high concentrations of aerosol particles can be toxic, as they can penetrate deep into our lungs, depositing their constituents, which can then even get into our blood streams.

Many aerosols are formed through secondary processes, that means they are not directly emitted into the atmosphere such as dust blown away from the soil by strong winds. No, they are formed in the atmosphere itself by gases, which have a low vapor pressure and are produced by chemical reactions. Secondary aerosols might be the dominant aerosol in the future, when many primary anthropogenic sources such as soot are reduced to air quality policies. However, secondary formation processes are highly dynamic, involving complicated chemical reaction schemes of the gaseous precursors and fast removal and growth processes of those mostly ultrafine (that means smaller than 100 nm) particles. Their small mass, high diffusivity and transient nature makes them extremely challenging to study. We thus constantly aim to develop new methods in characterizing ultrafine aerosol particles to follow our research mission: What’s the role of aerosols in the future atmosphere?

Urban areas are hotspots for climate change and air pollution. The urban aerosol system is complex, influenced by various sources that impact urban heat islands, local precipitation, and urban biological activity. New particle formation (NPF) is the primary source of particle number concentrations, where new particles are formed from gaseous precursors. NPF affects air quality by contributing to ultrafine aerosol pollution, which poses health risks and is being considered for inclusion in European air quality regulations.

Studying the interaction processes between the city-sphere, the atmosphere and aerosol formation is crucial for understanding urban environments and creating sustainable and healthy living spaces. In the future, urban aerosol sources will undergo significant changes due to a shift in car fleets and reduced industrial emissions. The importance of NPF as an aerosol source in urban areas will increase due to a reduced condensation sink provided by primary aerosols and the emergence of organic non-combustion emissions, so-called volatile chemical products (VCPs) evaporating e.g., from cleansing agents, personal care products, adhesives, coatings or asphalt.

The potential of these VCPs in forming and growing new aerosol particles is not well understood. Funded with 1.6 M€ by the Viennese Science Fund (WWTF) the Vienna Research Group (VRG) on Atmosphere-Cityscape Aerosol Interactions (ACAI) aims to investigate the role of VCP emissions and NPF in the environmental system of the city of the future. The VRG utilizes a multi-method, interdisciplinary approach, employing ultra-high-resolution chemical ionization mass spectrometry to identify gas-phase oxidation products from various VCP emitters in the laboratory and simultaneously constrain their functionalization via FTIR spectroscopy. In ambient measurements conducted in Seestadt, a newly developed district in Vienna and Europe's largest urban development area, the VRG directly measures NPF in an environment representative of future cities and aims to find molecular fingerprints of individual sources VCP sources tested in the laboratory.

By focusing on the organic oxidation chemistry involved in NPF and subsequent aerosol growth in urban environments, the VRG aims to provide valuable insights to air quality policymakers. This research can inform decisions related to building materials and urban planning, ultimately contributing to improved outdoor and indoor air quality.

Join our newly formed group, working on environmentally important topics, and shape the city of the future. Benefit from accessible supervision of a young PI, the usage of state-of-the-art experimental equipment, and outstanding international networking opportunities as we have project partners in Finland, Switzerland, Sweden and the US!

We always have interesting BSc and MSc thesis projects available. For PhD opportunities ask us!

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