Behavior of Parameters of Enhancements in the Nighttime Electron Concentration in the Ionospheric F2 Layer

We have analyzed the behavior of the F2 layer parameters during nighttime periods of enhanced electron concentration by the results of vertical sounding of the ionosphere carried out with five-minute periodicity in Almaty (76A degrees 55' E, 43A degrees 15' N) in 2001-2012. The results are obtained within the frameworks of the unified concept of different types of ionospheric plasma disturbances manifested as variations in the height and half-thickness of the layer accompanied by an increase and decrease of N (m) F2 at the moments of maximum compression and expansion of the layer. A good correlation is found between height h (Am) , which corresponds to the maximum increase, and layer peak height h (m) F, while h (Am) is always less than h (m) F. The difference between h (Am) and h (m) F linearly increases with increasing h (m) F. Whereas the difference is similar to 38 km for h (m) F = 280 km, it is similar to 54 km for h (m) F = 380 km. Additionally, the correlation is good between the increase in the electron concentration in the layer maximum Delta N (m) and the maximum enhancement at the fixed height Delta N; the electron concentration enhancement in the layer maximum is about two to three times lower than its maximum enhancement at the fixed height.