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

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_mF2 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_mF, while h_Am is always less than h_mF. The difference between h_Am and h_mF linearly increases with increasing h_mF. Whereas the difference is ~38 km for h_mF = 280 km, it is ~54 km for h_mF = 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.