Abstract
Horizontal wind systems in the ionospheric E region are deduced along the same line as in a previous paper [1]. This time, however, the wind systems on both northern and southern hemispheres in the solstice season are obtained. The wind systems thus obtained represent the actual state instead of the mean state as in Part I and II [1] [3], in the solstice season. In Part IV the effect of the Coriolis force is taken into account and an advance is made in the treatment in Part III where the wind velocity is simply assumed to be irrotational [4].
It is shown, as in Part III, that in summer the diurnal wind motion is predominant over the semi-diurnal, whereas in winter the velocity of the former is almost the same as that of the latter. Further the diurnal wind velocity is greater in summer than in winter and the semi-diurnal wind velocity is somewhat smaller in summer than in winter.
Some differences are found between the results of Part III and IV. However, more observational material than available at present must be accumulated before discussing these differences,
