Differences Between the Response of the Equatorial TEC and foF2 to Solar Soft X-ray Irradiances

Measurements of the solar soft X-ray irradiances from the SNOE satellite; the TEC from Ancon, Peru; and the foF2 from Jicamarca, Peru have been compared for a period of almost two years. While both TEC and foF2 have a significant response to changes in the solar irradiances, each responds differently. At noon time, solar irradiances have a stronger correlation with TEC than with foF2 and the solar irradiances lead TEC by ~1 day but they do not lead foF2. At earlier local times, the solar irradiances have a stronger correlation with foF2 than with TEC. The solar irradiances lead TEC by ~2 days and foF2 by ~1 day. The study shows that the ionospheric densities have a more significant dependence on solar soft X-ray irradiances than on F10.7.