Similarities and differences between regular variations of F2-layer parameters of the polar and midlatitude ionosphere in East Siberian sector

Analysis of similarities and differences between the polar and midlatitude ionosphere in the East Siberian sector was performed with local ionosphere models. The local models were constructed using 6-year (December 2002 - December 2008) continuous measurements made with ionosondes located in Norilsk (69.4° N, 88.1° E) and Irkutsk (52.3° N, 104.3° E). The models describe variations of regular ionospheric parameters in terms of diurnal and seasonal variations under low solar activity and their changes with increasing solar activity. The paper discusses regular variations of the main F2-layer parameters: the electron density maximum ( N mF2) and the peak height ( h mF2). Special attention has been given to the manifestation of such phenomena as the winter anomaly, semiannual anomaly, summer evening anomaly, and formation of the winter night peak at the polar and mid-latitude stations. The specific diurnal and seasonal behavior of h mF2 in Norilsk is explained by the maximum magnetic inclination and the lowest geomagnetic latitude compared to other polar stations located at the same geographic latitude.