Ionosphere as an Indicator of Processes in the Geospace,Troposphere, and Lithosphere

The possible causes of the strong ionospheric day-to-day variability under the influence of processes in the geospace, troposphere, and lithosphere are considered based on the data of the critical frequency of the F2 layer of the ionosphere at two observation stations. It is shown that even in the absence of powerful events, the ionosphere is influenced both “from above” and “from below”; in this case, the ionosphere can respond to an external action as an open nonlinear dissipative system.