Aerosol particles act as nuclei for cloud droplets in the atmosphere. Aerosols are, therefore, important players in determining the properties and lifetimes of cloud properties, and the aerosol-cloud interactions have a significant role in the Earth’s climate system. The size and composition of an aerosol particle affects its ability to act as cloud condensation nuclei. There are still unknowns in the composition dependence of the cloud droplet forming ability, especially for the organic aerosols. Our laboratory facilities and instrumentation allows as to study water uptake of model aerosol systems. The unique measurement station at the top of the Puijo-tower, which is maintained in collaboration with the Finnish Meteorological Institute, facilitates in-cloud measurements of aerosol properties and cloud droplet activation. Our group’s research objects related to aerosol-cloud interactions are:

  • hygroscopicity of aerosol particles under sub- and super-saturation
  • cloud droplet activation


Relating articles

  • Romakkaniemi, S., Maalick, Z., Hellsten, A., Ruuskanen, A., Väisänen, O., Ahmad, I., Tonttila, J., Mikkonen, S., Komppula, M., and Kühn, T. (2017)
    Aerosol–landscape–cloud interaction: signatures of topography effect on cloud droplet formation
    Atmos. Chem. Phys., 17, 7955-7964, doi:10.5194/acp-17-7955-2017.
  • Väisänen, O., Ruuskanen, A., Ylisirniö, A., Miettinen, P., Portin, H., Hao, L., Leskinen, A., Komppula, M., Romakkaniemi, S., Lehtinen, K. E. J., and Virtanen, A. (2016)
    In-cloud measurements highlight the role of aerosol hygroscopicity in cloud droplet formation
    Atmos. Chem. Phys., 16, 10385-10398, doi:10.5194/acp-16-10385-2016.
  • Dalirian, M., Keskinen, H., Ahlm, L., Ylisirniö, A., Romakkaniemi, S., Laaksonen, A., Virtanen, A., and Riipinen, I. (2015)
    CCN activation of fumed silica aerosols mixed with soluble pollutants
    Atmos. Chem. Phys., 15, 3815-3829, doi:10.5194/acp-15-3815-2015.
  • Hansen, A. M. K., Hong, J., Raatikainen, T., Kristensen, K., Ylisirniö, A., Virtanen, A., Petäjä, T., Glasius, M., and Prisle, N. L. (2015)
    Hygroscopic properties and cloud condensation nuclei activation of limonene-derived organosulfates and their mixtures with ammonium sulfate
    Atmos. Chem. Phys., 15, 14071-14089, doi:10.5194/acp-15-14071-2015.
  • Portin, H., Leskinen, A., Hao, L., Kortelainen, A., Miettinen, P., Jaatinen, A., Laaksonen, A., Lehtinen, K. E. J., Romakkaniemi, S., and Komppula, M. (2014)
    The effect of local sources on particle size and chemical composition and their role in aerosol–cloud interactions at Puijo measurement station
    Atmos. Chem. Phys., 14, 6021-6034, doi:10.5194/acp-14-6021-2014
  • Jaatinen, A., Romakkaniemi, S., Anttila, T, Hyvärinen, A.-P., Hao, L. Q., Kortelainen, A., Miettinen, P., Mikkonen, S., Smith, J. N., Virtanen, A. & Laaksonen, A. (2014)
    The third Pallas Cloud Experiment: Consistency between the aerosol hygroscopic growth and CCN activity.
    Boreal Env. Res. 19 (suppl. B): 368–382. Reprint (PDF)