Enell, C.-F.1, Verronen, P. T.2, Seppälä, A. M.2, Kero, A.1, Ulich, Th.1 and Turunen, E.1
1 Sodankylä Geophysical Observatory, Sodankylä, Finland
2 Earth Observation unit, Finnish Meteorological Institute, Helsinki, Finland
Although the mesosphere is almost neutral, coupling between ion and neutral chemistry affects the concentrations of species determining its structure and radiative balance, such as odd nitrogen and ozone. This is especially the case during events of high ionisation, such as solar flares.
The Sodankylä coupled Ion-neutral Chemistry model (SIC) has been developed specifically for modelling these processes, including reactions of negative ions and water cluster ions. This talk presents case studies of the effect of solar X rays and extreme UV radiation. The SIC results are compared with local measurements by EISCAT and riometers.