We analyzed ionospheric observations made with digisondes in Jicamarca, Ramey, Wallops Island, Ascension Island, and Kwajalein Island during the major magnetic storm of November 9–10, 2004, which was associated with rapid interplanetary magnetic field (IMF) Bz changes. The strongest ionospheric responses ...

Groundbased ionograms measure the Chapman scale height HT at the F2-layer peak that is used to construct the topside profile. After a brief review of the topside model extrapolation technique, comparisons are presented between the modeled profiles with incoherent scatter radar and satellite measurements ...

This study is the first attempt to examine the quiet-condition variations in scale height (Hm) near the F2-layer peak in the equatorial ionosphere. The data periods of Hm derived from the Jicamarca ionograms are January-December 1996 and April 1999–March 2000. The results show that the greatest and ...

The Jicamarca (11.95°S, 76.87°W) digisonde and the Arequipa (16.47°S, 71.49°W) GPS receiver observed the equatorial F region irregularities on the western South America from April 1999 to March 2000. The spread F measured by the digisonde were classified into four types, and the GPS phase fluctuations ...

The National Center for Atmospheric Research thermosphere/ionosphere/electrodynamic general circulation model (TIEGCM) is one of the few models that self-consistently solves the coupled equations for the neutral atmosphere and ionosphere. Timely questions are how well the TIEGCM currently simulates ...