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The equatorial F-region of the ionosphere

1960; Elsevier BV; Volume: 18; Issue: 2-3 Linguagem: Inglês

10.1016/0021-9169(60)90081-7

1878-593X

R. A. Duncan,

Geomagnetism and Paleomagnetism Studies

A comparison of data from ionospheric sounders at Chimbote and Panama, shows that afternoon critical frequencies in the equatorial zone are negatively correlated with those on the same meridian in the sub-tropical belts. This supports Martyn's suggestion that ionization is transported from the equatorial zone to the sub-tropics. The process suggested by Martyn, electrodynamic lift at the equator followed by diffusion under gravity along the geomagnetic field lines to the sub-tropical belts, is investigated quantitatively, and it is shown that the process can account for the high sub-tropical electron densities observed. It is shown that the diurnal variation of the correlation between Chimbote and Panama critical frequencies, the diurnal variation in the height, thickness and electron density of the equatorial F-region, and the diurnal variation of electron density enhancement in the sub-tropics, can all be ascribed to the simple diurnal electrodynamie tide expected from the observed magnetic variations, in conjunction with diffusion along the geomagnetic field lines.