Journal article

Aerosol charging state at an urban site: New analytical approach and implications for ion-induced nucleation

Gagn?? S, Lepp?? J, Pet??j?? T, McGrath M, Vana M, Kerminen V, Laakso L, Kulmala M ...see all

Atmospheric Chemistry and Physics, vol. 12, issue 10 (2012) pp. 4647-4666 Published by Copernicus GmbH

  • 8


    Mendeley users who have this article in their library.
  • 6


    Citations of this article.
Sign in to save reference


The charging state of aerosol populations was determined using an
Ion-DMPS in Helsinki, Finland between December 2008 and February 2010.
We extrapolated the charging state and calculated the ion-induced
nucleation fraction to be around 1.3 % +/- 0.4 % at 2 nm and 1.3 %
+/- 0.5 % at 1.5 nm, on average. We present a new method to retrieve
the average charging state for a new particle formation event, at a
given size and polarity. We improve the uncertainty assessment and
fitting technique used previously with an Ion-DMPS. We also use a new
theoretical framework that allows for different concentrations of small
ions for different polarities (polarity asymmetry). We extrapolate the
ion-induced fraction using polarity symmetry and asymmetry. Finally, a
method to calculate the growth rates from the behaviour of the charging
state as a function of the particle diameter using polarity symmetry and
asymmetry is presented and used on a selection of new particle formation

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text


  • St??phanie Gagn??

  • J. Lepp??

  • T. Pet??j??

  • M. J. McGrath

  • M. Vana

  • V. M. Kerminen

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free