1University of Helsinki, Department of Physics, Helsinki, 00014 University of Helsinki, Finland
2Helsinki Institute of Physics, P.O. Box 64, 00014 University of Helsinki, Finland
3Finnish Meteorological Institute, Climate Change Unit, 00101 Helsinki, Finland
4Lund University, Department of Physics, Lund, 22100 Lund, Sweden
5Tampere University of Technology, Dept. of Physics, P.O. Box 692, 33101 Tampere, Finland
6Department of Physical Geography and Ecosystems Science, Sölvegatan 12, 223 62 Lund, Sweden
7Karlsruher Institute of Technology, Instute of Meteorology and Climate Research/Atmospheric Environmental Research (IMK-IFU), Kreuzeckbahnstr. 19, 82467 Garmisch-Partenkirchen, Germany
Abstract. We investigated atmospheric aerosol particle dynamics in a boreal forest zone in Northern Scandinavia. We used aerosol size distribution data measured with either a Differential Mobility Particle Sizer (DMPS) or Scanning Mobility Particle Sizer (SMPS) at three stations (Värriö, Pallas and Abisko), and combined these data with the HYSPLIT air mass trajectory analysis. We compared three approaches: analysis of new particle formation events, investigation of air masses transport from the ocean to individual stations with different over-land transport times, and analysis of changes in aerosol particle size distributions during the air masses transport from one measurement station to another. Aitken mode particles were found to have an apparent average growth rate of 0.6–0.7 nm h−1 when the air masses travelled over land. Particle growth rates during the NPF events were 3–6 times higher than the apparent particle growth. When comparing aerosol dynamics between the different stations for different over-land transport times, no major differences were found except that in Abisko the new particle formation events were observed to take place in air masses having shorter over-land times than at the other stations. We speculate that this is related to the meteorological differences along the paths of air masses caused by the land surface topology. When comparing between air masses travelling the east-to-west direction to those traveling the west-to-east directions, clear differences in the aerosol dynamics were seen. Our results suggest that the condensation growth has an important role in aerosol dynamics also when new particle formation is not evident.