F-region of the ionosphere

In the E and the lower F regions of the ionosphere, photochemical processes dominate, and the electron density canbe calculated simply by equating local production aiKl loss rates,... 

Fig. 5. Ionospheric electron density vs height above the earth at the extremes (A = minimum, B = maximum) of the 11-yr sunspot cycle during (a) day and (b) night (54). D, E, F, F, and F2 are conventional labels for the indicated regions of the ionosphere.

F region Region of the ionosphere extending from about 145 to 1000 km above the earth, where atomic ions play a major role. 

Above approximately 80 km, the prominent bulge in electron concentration is called the ionosphere. In this region ions are created from UV photoionization of the major constituents—O, NO, N2 and O2. The ionosphere has a profound effect on radio conmumications since electrons reflect radio waves with the same frequency as the plasma frequency, f = 8.98 x where 11 is the electron density in [147]. The... 

The effect of efficient dissociative recombination is reflected in the daytime ionospheric charged particle densities shown in Fig. 2. In the FJ-region, 02 and NO+ are the most abundant ions, while in the F-region, the higher plasma densities due to increased photoionization rates dramatically reduces the abundance of all molecular ions and 0+ is the principal positively charged species. Figure 2 also depicts a typical metal ion density profile (Me" ") around 100 km. As will be outlined further, this profile can be... 

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