Abstract: The high latitude Earth’s atmosphere is ionized via direct solar radiation. This results in the formation of positively charged ions through, e.g., photoionization and the ionization of NO. A one-dimensional chemical and climatic model with interactive neutral and ionic chemistry is used to track the ionic compositions of the D region of the ionosphere on daily and seasonal scales. It is found that ion clusters dominate the total ion content up to altitudes of 95 km in winter and 80 km in summer.