lonization transport effects in the equatorialFregion

Solutions of the continuity equation for electrons in the F2 region of the earth's ionosphere are obtained for the region near the magnetic equator under noon conditions. The physical processes of photo-ionization, recombination, diffusion, neutral winds, and electromagnetic drift are included explicitly in the equation; the presence of light ions (H+, He+) and the effects of ion drag, however, are specifically ignored. It is shown that upward plasma drift at the equator is very likely the cause of the Appleton anomaly, as originally suggested by Martyn; a drift velocity of about 10 m sec−1 is required. Other cases with downward drift or with neutral winds are presented. It is shown that a 15% interhemisphere asymmetry in the electron concentration at the Appleton peaks can be caused by a 60 m sec−1 neutral wind blowing from north to south. By using a very small drift velocity the time-dependent behavior of the electron concentration along particular field lines is investigated for different initial conditions.