Abstract
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 (76°55′ E, 43°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 ~38 km for h m F = 280 km, it is ~54 km for h m F = 380 km. Additionally, the correlation is good between the increase in the electron concentration in the layer maximum ΔN m and the maximum enhancement at the fixed height ΔN; the electron concentration enhancement in the layer maximum is about two to three times lower than its maximum enhancement at the fixed height.