Maps of ƒ₀F₂ derived from observations and theoretical data

Abstract

Observations of the F 2 region critical frequency, foF2, and values determined from the timedependent continuity equation for ions and electrons in the ionosphere have been used to develop a new set of numerical coefficients to represent the global variation of foF2 . Like those in earlier investigations, the new coefficients permit monthly median hourly values OffoF 2 to be obtained at any location around the globe for any month of the year and solar activity level. Comparisons between foF2 determined using older sets of numerical coefficients and foF 2 determined using the new set of coefficients are given along with a description of how well each set of coefficients specifies and predicts the observed variations in the F 2 region critical frequency.

A new global model for the ionospheric F2 peak height for radio wave propagation

“…Similar work was done by Jones and Obitts (1970), Rush et al (1983Rush et al ( , 1984, Fox and McNamara (1988), Bilitza et al (1990), Bilitza (2001), and Bilitza and Reinisch (2008) in developing global ionospheric parameter models. Considering the importance of ionospheric characteristics in radio frequency planning, the International Telecommunications Union (ITU) issued a standard set of ionospheric parameter models (CCIR, 1967;ITU-R, 1997) on advice from its International Radio Consultative Committee (CCIR), presently from its Radio-Communication Sector (ITU-R).…”

Effect of vertical plasma transport on ionospheric F2-region parameters at equatorial latitude

“…The production rate q e is assumed to be given by the usual Chapman function (Chapman, 1931) with a maximum value at about 180 km above the Earth, and the recombination rate is defined by a linear loss coefficient b, which decreases exponentially with height. The only ion of concern in this work was atomic oxygen (O + ), a valid approximation for F2-region heights (Rush et al, 1984). The analysis is carried out at 300 km altitude under the tacit assumption that the parameters in the continuity equation are limited to the F2-layer at around this height (Chaman, 1997).…”

Towards the development of a new global foF2 empirical model using neural networks

“…The principal ionospheric layer for high frequency (HF) propagation predictions is the F2-layer (Nibset, 1971;Bent et al, 1978;Rush et al, 1983Rush et al, , 1984Kumluca et al, 1999), and thus it requires prediction with an acceptable minimum error.…”