Seasonal cycle, size dependencies, and source analyses of aerosol optical properties at the SMEAR II measurement station in Hyytiälä, Finland
A. Virkkula, J. Backman, P. Aalto, M. Hulkkonen, L. Riuttanen, T. Nieminen, M. D. Maso, L. Sogacheva, G. Leeuw, M. Kulmala