1Department of Physics, University of Helsinki, 00014 Helsinki, Finland
2Finnish Meteorological Institute, Research and Development, 00101 Helsinki, Finland
3Department of Applied Environmental Science & Bert Bolin Centre for Climate Research, Stockholm University, 11418, Stockholm, Sweden
4Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas (ICEHT/FORTH), Patras, Greece
5Finnish Meteorological Institute, Kuopio Unit, 70211, Kuopio, Finland
6Division of Nuclear Physics, Lind University, P.O. Box 118, 22100 Lund, Sweden
Abstract. This paper synthesizes the available scientific information connecting atmospheric nucleation with subsequent Cloud Condensation Nuclei (CCN) formation. We review both observations and model studies related to this topic, and discuss the potential climatic implications. We conclude that CCN production associated with atmospheric nucleation is both frequent and widespread phenomenon in many types of continental boundary layers, and probably also over a large fraction of the free troposphere. The contribution of nucleation to the global CCN budget spans a relatively large uncertainty range, which, together with our poor understanding of aerosol–cloud interactions, results in major uncertainties in the radiative forcing by atmospheric aerosols. In order to better quantify the role of atmospheric nucleation in CCN formation and Earth System behavior, more information is needed on (i) the factors controlling atmospheric CCN production and (ii) the properties of both primary and secondary CCN and their interconnections. In future investigations, more emphasis should be put on combining field measurements with regional and large-scale model studies.