Abstract
The study of foF2 data measured every 5-min and of TEC measurements made every 10-min shows that the within-the-hour variability is different in the two parameters. Deciles of this variability for foF2 and for TEC are determined together with the probabilities of exceeding a given level of variability. Furthermore, considering hourly values, it is found that the variability in TEC is like an «intrinsic noise» throughout the day of the order of less than 5% of the hourly value; but at sunrise and often at sunset large values take place. A seasonal dependence is evident. Besides, a within-the-hour variability in foF2 is always present with large values at sunrise or sunset depending on the season, and also during disturbed ionospheric conditions.
Highlights
Perturbations of ionization density at the heights of the ionospheric F-region are permanent features
Variability in TEC – The analysis shows that the within-the-hour variability in TEC has a different behavior from that in foF2
Only an «intrinsic» variability of the order of less than 5% is found, comparative to the one found for all other ionospheric characteristics, e.g. foE (Kouris and Fotiadis, 2002)
Summary
Perturbations of ionization density at the heights of the ionospheric F-region are permanent features. First we evaluate the 10-min relative deviations of TEC from the measured every 10-min daily values in each interval time of an hour (half an hour before and after each standard hour) of each day/month/year/location using the expression dT =
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
