Seasonal variations in daily maximum of electron density in the F2 ionospheric layer depending on solar activity according to the Tomsk ionospheric station data

The paper analyzes variations in the maximum electron density of the F2 ionospheric layer (NmF2), using data from the Tomsk ionospheric station for the period from 1947 to 2024, including seven 11-year solar cycles, with the aim of identifying seasonal changes in daily NmF2 maxima in the mid-latitude ionosphere and their relationship with solar activity. Seasonal-daily variations of NmF2 were constructed separately for low and high solar activity levels. Linear and quadratic models of the regression dependence of the NmF2 daily values on the F10.7 index are calculated for each month of the year. Regression models are computed for both monthly medians and daily data. Quantitative comparisons and resistance factors of different models for different types of data aggregation are given.