Abstract
Abstract. 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 smallest Hm values are generally at 11:00–12:00 LT and 04:00–05:00 LT, respectively. Additionally, the sunrise peak occurs at 06:00 LT only during solar minimum. The post-sunset peaks in the equinoctial and summer months are more obvious during solar maximum. The Hm difference between solar minimum and maximum are significant from afternoon to midnight. On the other hand, the Hm values during 07:00–10:00 LT for solar minimum are close to those for solar maximum. Furthermore, the correlation of Hm with the critical frequency (foF2) of F2-layer is generally low. In contrast, the correlation between Hm and the peak height (hmF2) of F2-layer is high. For Hm and the thickness parameter (B0) of F2-layer, the correlation between these two parameters is almost perfect.
Highlights
The understanding of the electron density profile, which is the altitude distribution of electron density, is important for the ionospheric studies
We analyze for the first time, the diurnal and seasonal variations of the scale height (Hm) at F2-layer peak near the dip equator during the solar minimum and maximum
The Hm values are derived from the Jicamarca ionograms from January to December 1996 and from April 1999 to March 2000
Summary
The understanding of the electron density profile, which is the altitude distribution of electron density, is important for the ionospheric studies. The profile can be obtained from the ISR, the space-born instruments (e.g. Stankov et al, 2006), or by analytic functions. In Huang and Reinisch (2001) and Reinisch and Huang (2001), a new technique was introduced to derive the scale height (Hm) near the F2-layer peak from the shape of the bottomside profile. Reinisch et al (2004) showed that the Hm can help to improve the model of topside profile in International Reference Ionosphere (IRI) (Bilitza, 2001). The diurnal, seasonal, and solar activity variations of Hm at Wuhan (30.6◦ N, 114.4◦ E) and the yearly variation of Hm of Wuhan and 12 other stations were investigated by Liu et al (2006). The correlations of Hm with the critical frequency (foF2), peak height (hmF2), and thickness parameter (B0) of F2-layer are analyzed here
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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 call
