Variations of ionospheric parameters over Almaty (Kazakhstan) in 1999-2013

The paper presents the results of a study of the behavior of ionospheric parameters of the total electron content, I ( t ), and electron density in the maximum F2 layer, N m, over Almaty (Kazakhstan) [43.25° N; 76.92° E] in 1999-2013. The time interval under study covers different solar activity levels. We have shown that at F 10.7>175 in summer and at F 10.7>225 in winter there is a saturation effect, i.e. with increasing solar activity level values of I ( t ) do not increase. The observed nonlinear relationship between the total electron content of the ionosphere and the solar radiation flux F10.7 results from the nonlinear relationship between the solar ultraviolet radiation and the solar radiation flux. The study of the variability of the mid-latitude ionosphere parameters during different solar and geomagnetic activity levels has shown that the standard deviation ( x ) and average shift x ave of I ( t ) and N m fluctuations relative to the quiet level weakly depend on solar activity, but greatly depend on geomagnetic activity when F 10.7