Ionosphere is a complex system usually analyzed in terms of long-term trends versus short-term fluctuations. This contribution hence performs a scale-dependent cross-analysis of the F2-region critical frequency data, locally measured at 11 mid-latitude European stations, and 5 global solar and geomagnetic indices. It shows that such Ionospheric variations are well described by the superimposition of well-defined long-term cycles with highly correlated fractional Gaussian noise fluctuations. Also, it is shown that mid-latitude European stations display highly correlated variations even for short-term fluctuations and that, while the solar activity mostly drives long-term cycles, short-term fluctuations are essentially controlled by the geomagnetic activity.

In the proposed paper we analyze variability of the stratospheric parameters by mean of classical spectral analysis and wavelet analysis over period range of hours to several days covering tidal and planetary oscillation domains. Detected wave-like oscillations are further classified and compared to the wave-like bursts detected within ionospheric plasma mainly in the E region. Special campaigns were run since 2004 in order to collect data related to Sporadic E layer. Within time series of foEs and hEs there are significant oscillations that could be linked to the corresponding wave bursts within neutral stratosphere.