The Atmospheric Aerosols group operates within the Institute for Atmospheric and Earth System Research (INAR) at University of Helsinki, Faculty of Science. We perform both long-term and campaign-wise measurements on atmospheric aerosols in various environments and conduct laboratory experiments. Our aim is to increase the understanding of the physical properties of aerosol particles and the processes affecting the atmospheric aerosol population. Thereby we help in reducing the uncertainties related to the effect of aerosols on climate and human health.