The Effect of the Solar Tides and the Temperature Change on the Daily Variation in Electron Density and Height of the F2-Layer

Abstract

Chapman's ion-production function in an isothermal ionosphere is first reformed for the convenience of applying it to the ionosphere with the temporal variation of temperature. Then using this ionization function, the equation of motion and the equation of continuity are solved, taking both the thermal- and tidal- variations into account. As a result, the maximum electron density and its corresponding height can be obtained for each hour during a day. Departures of these from the norm of the static Chapman region indicate that the behaviour of this departure Δnm is very different from that by Weiss [6], who deals only with tidal effect on the ionosphere. In our case it is inversely proportional to the temperature variation in the course of a day except in the morning when the electron density is very small. It is also noted that the semidiurnal variation in Δnm appears even in the case of taking into account only the diurnal variation in temperature but not the tidal variation. As regards the behaviour of Δhm, the result similar to Weiss' can be seen, but with the reasonable difference that it is much raised and lowered by thermal expansion and contraction in the afternoon (high temperature) and in the morning (lower temperature), respectively. Further, the effect of temperature variation and tidal one exerted simultaneously on the daily variations in the maximum electron density and its height seem to show the complicated mutual interaction between these two effects.