5 research outputs found
TEC and foF2 variations: preliminary results
Investigation of the relationship between TEC and (foF2)2 shows that although they are highly correlated, a «hysteresis» effect exists between them. The slab thickness is greater before than after mid-day for equal cos ?values. Moreover, a comparison of the calculated upper and lower quartiles of variability in TEC, foF2 and Nmax, respectively shows that the variability of TEC lies between those of foF2 and Nmax depending on the level of solar activity
TEC and foF2 variations: preliminary results
Investigation of the relationship between TEC and (foF2)2 shows that although they are highly correlated, a «hysteresis» effect exists between them. The slab thickness is greater before than after mid-day for equal cos ?values. Moreover, a comparison of the calculated upper and lower quartiles of variability in TEC, foF2 and Nmax, respectively shows that the variability of TEC lies between those of foF2 and Nmax depending on the level of solar activity
Within-the-hour variability: levels and their probabilities
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
TEC and foF2 variations: preliminary results
Investigation of the relationship between TEC and (foF2)2 shows that although they are highly correlated, a «hysteresis» effect exists between them. The slab thickness is greater before than after mid-day for equal cos ?values. Moreover, a comparison of the calculated upper and lower quartiles of variability in TEC, foF2 and Nmax, respectively shows that the variability of TEC lies between those of foF2 and Nmax depending on the level of solar activity.PublishedJCR Journalope
Within-the-hour variability: levels and their probabilities
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