Planetary and gravity wave signatures in the F-region ionosphere with impact on radio propagation predictions and variability

The aim of this work within the WP 3.1 of the COST 271 Action is the characterization of the variability introduced in the F-region ionosphere by 'Planetary Wave Signatures' (PWS) and 'Gravity Wave Signatures' (GWS). Typical patterns of percentage of time occurrence and time duration of PWS, their climatology and main drivers, as well as their vertical and longitudinal structure have been obtained. Despite the above characterization, the spectral distribution of event duration is too broad to allow for a reasonable prediction of PWS from ionospheric measurements themselves. GWS with a regular morning/evening wave bursts and specific GWS events whose arising can be predicted have been evaluated. As above, their typical pattern of occurrence and time duration, and their vertical structure have been obtained. The latter events remain in the ionospheric variability during disturbed days while additional wave enhancements of auroral origin occur. However, both types of disturbances can be distinguished.