Ionospheric F2 Behavior at Coniugate Places in Low Latitudes

After a brief review of the current knowledge of ionospheric F2 conjugate behavior in low latitudes, temporal variations of foF2 at several low-latitude conjugate pairs are examined for the period from IGY through IQSY. Although the monthly median values of foF2 at conjugate stations showed poor correlations, deviations from the median values, ΔfoF2, on individual days exhibited positive conjugate correlations in all seasons for both geomagnetically quiet and disturbed periods. Furthermore, a negatively correlated temporal variation of ΔfoF2 was discovered between the equatorial zone (L < 1.09) and the low-latitude zone (1.1 < L < 1.3). All of these results indicate a strong diffusion effect along field lines.

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