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The behaviour of the topside ionosphere at middle latitudes at night

1968; Elsevier BV; Volume: 30; Issue: 9 Linguagem: Inglês

10.1016/0021-9169(68)90008-1

1878-593X

Jonathan King, H.G Rix, C. Seabrook,

GNSS positioning and interference

Data obtained by means of two different satellites and also from ground-based observatories have been used to study the relationship between the ionosphere at an altitude of 1000 km and at the peak of the F2-layer. Because of the change in ion composition and, hence, in electron scale height, which accompanies the cooling of the topside ionosphere at night, the diurnal variations of electron concentration at the two heights are quite different. The large maxima in the electron concentration at 1000 km, observed by Bace et al. (1967) near 40° geomagnetic latitude at night during 1965, appear to be less evident during years of higher sunspot number. It is suggested that the maxima may be associated with the relatively large decrease in electron temperature which occurs between day and night at 35°N and S geomagnetic latitude.