The authors have addressed all the referee comments. The paper can be accepted for publication in ACP after the authors have considered the following, minor technical issues:

1) The correct ways to cite Asmi et al. in the text is Asmi et al. (2011a) and Asmi et al. (2011b), not by using Asmi, A. or Asmi, E.

2) In Table 4 the citation should be Dal Maso et al. (2005), not Maso et al.

3) In the reference list, all journal names should be shortened correctly (i.e. Atmos. Chem. Phys.; J Geophys. Res. etc) and doi-indices should be added whenever needed.

Editor