Longitudinal variations of the electron concentration in the ionospheric shape D region

Abstract

[1]  Analysis of the longitudinal effects in the lower ionosphere revealed from the measurements by rockets and partial reflection method is presented. It is shown that in the summer and equinox periods the electron concentration in the altitude range 70-85 km at fixed zenith angle varies by a factor of 1.5-5.6 at the transition from the Pacific longitudinal sector to the Eurasian and American sectors. The longitudinal effects depend on season and time of the day: they are weak in the American sector and strong in the Eurasian sector. A conclusion is drawn that to reconstruct the longitudinal features of the global structure of the lower ionosphere, it is reasonable to attract the data obtained by the A1 method.

Received 8 June 2004; revised 1 February 2005; accepted 2 May 2005; published 20 September 2005.

Keywords: Ionospheric D region; Empirical modeling; Electron concentration.

Index Terms: 2447 Ionosphere: Modeling and forecasting; 2443 Ionosphere: Midlatitude ionosphere; 2494 Ionosphere: Instruments and techniques.