Ilona RiipinenHead of unit
Phone: +46 8 674 7284
Mobile: +46 73 585 9251
What I do
The air we breathe does not consist of gas molecules only: each cubic centimetre of atmospheric air typically contains thousands of small aerosol particles. These liquid or solid airborne particles originate from both natural sources (e.g. forests, oceans, deserts) as well as human activities (e.g. combustion processes, traffic), and their diameters span from nanometres to hundreds of micrometres.
Atmospheric aerosol particles play an important role in defining the environments we live in. When inhaled, many particles are harmful to human health. Atmospheric particles also decrease visibility and damage buildings and landmarks when deposited on their surfaces. On global scale, aerosols regulate the Earth’s energy balance and therefore the climate. In current climate models aerosols are still poorly represented: the Intergovernmental Panel on Climate Change recognizes aerosols as the largest individual source of uncertainty in calculations of the Earth’s radiative forcing.
My research focuses on understanding the sources, sinks and evolution of atmospheric aerosol particles and their interactions with clouds, climate and human health. My current focus is largely on the interactions between aerosol particles and the atmospheric gas phase, in particular the formation and effects of atmospheric organic aerosol and thus the feedback between ecosystems, human activities and climate.
Together with my colleagues, I work mainly with atmospheric computational models representing the processes governing the evolution and impacts of atmospheric aerosol populations. We model the evolution of atmospheric aerosol from the molecular to the global scale, with a tight connection to experimental data from both laboratory and field studies. The underlying philosophy is that to correctly upscale the molecular level processes to global scale, the scientists working on the fundamental theory need to be brought together with the scientists working on the highly simplified aerosol descriptions in regional and global atmospheric models.
Alumni (PhD students and post-docs I have mentored)
Dr. Erica Trump (Carnegie Mellon University, now at OSIsoft)
Dr. Taina Yli-Juuti (University of Helsinki, now at University of Eastern Finland)
Dr. Benjamin Murphy (Stockholm University, now at US Environmental Protection Agency)
Dr. Silja Häme (formerly Häkkinen) (University of Helsinki, now at University of Helsinki)
Dr. Juan Camilo Acosta Navarro (Stockholm University, now at Barcelona Supercomputing Center)
Dr. Elham Baranizadeh (University of Eastern Finland, now at University of California Riverside)
Dr. Jan Julin (Stockholm University, now at ThermoCalc AB)
Dr. Lars Ahlm (Stockholm University, now at ÅF AB)
Dr. Maryam Dalirian (Stockholm University)
Dr. Narges Rastak (Stockholm University, now at Helmholtz Zentrum Munich)
Dr. Jenni Kontkanen (Stockholm University, now at University of Helsinki)
Dr. Tanja Dallafior (Stockholm University, now at RMS – Risk Management Solutions Inc.)
Major part of my work is funded by the European Research Council starting grant ATMOGAIN (grant No 278277-ATMOGAIN), Vetenskapsrådet, Formas and the Wallenberg Academy Fellowship program.
Latest scientific papers
Interactions between the atmosphere, cryosphere and ecosystems at northern high latitudes
Impacts of future European emission reductions on aerosol particle number concentrations accounting for effects of ammonia, amines and organic species
Exploring the potential of nano-Köhler theory to describe the growth of atmospheric molecular clusters by organic vapors using cluster kinetics simulations