Sodankylä Geophysical Observatory

Sodankylä Ion Chemistry Model

The Sodankylä Ion-Neutral Chemistry (SIC) model is a comprehensive 1-dimensional coupled model of the chemistry of the middle atmosphere, i.e. the mesosphere and lower thermosphere as well as the ionospheric D region. SIC has been developed by SGO under the lead of Dr Esa Turunen in close collaboration with the Finnish Meteorological Institute.

SIC includes more than 400 reactions of

  • 36 positive ions,
  • 27 negative ions, and
  • 14 neutral constituents.

See SIC chemistry for a list of all constituents.

Sources of ionisation accounted for are solar UV, X-rays, protons and electrons, as well as galactic cosmic rays.

The model is described in Turunen et al., [1996], Verronen et al., [2005] and Turunen et al., [2009]. The current version of the model is particularly designed to be used as an inversion tool for the energetic particle precipitation (see e.g., Turunen et al., [2016] and Miyoshi et al., 2021).

The SIC Model is used extensively in our international research network CHAMOS (Chemical Aeronomy of the Mesosphere and Ozone in the Stratosphere). All members of the SIC model team are also members of the larger CHAMOS Network.


  • Asst. Prof. Antti Kero, SGO
  • Prof. Pekka Verronen, SGO and FMI/Space and Earth Observation Centre


SIC Developers

  • Dr Esa Turunen, adj. prof., SGO
  • Prof. Pekka Verronen, SGO and FMI
  • Asst. Prof. Antti Kero, SGO
  • Dr Carl-Fredrik Enell, adj. prof., SGO (now at EISCAT)
  • Dr Thomas Ulich, adj. prof., SGO
  • Prof. Annika Seppälä, FMI (now at U Otago, NZ)
  • Dr Monika Szeląg, FMI

Last modified: 13 January 2022, 13:09:49.

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