[en] The seasonal and solar cycle dependences of the ionosphere over Chatanika, Alaska, as deduced from 108 experiments conducted over the course of an 11-year period, have yielded electron concentrations, electron and ion temperatures, and line-of-sight in velocities, as functions of altitude and time. Attention is presently given to E and F region ionization. Empirical relationships are established which allow the daytime maximum E region electron concentrations to be expressed in terms of the 10.7-cm solar flux and the solar zenith angle, and also permit the expression of the daytime maximum F region electron concentration in terms of the 10.7-cm solar flux alone. The dependence of nighttime precipitation-produced ionization in both the E and F regions on solar flux and magnetic activity is noted, together with a clear distinction between summer and winter F region ionization conditions. 7 references