MOVEMENTS OF IONOSPHERIC IRREGULARITIES AND ATMOSPHERIC WINDS

The various phenomena which are associated with motions or apparent motions in the ionosphere are outlined, and the ways in which the atmosphere may be divided into regions are briefly examined, particularly in relation to the interaction between the neutral atmosphere and the ionisation. The sources of movements in these regions are discussed, and the irregularities in the ionosphere and their origin are also examined. The various methods for measuring movements or apparent movements in the ionosphere are summarized. The experimental results so far available are sketched out with emphasis placed upon establishing what reliable evidence there is for real mass movement of both plasma and neutral atmosphere throughout the ionosphere. In the lower ionosphere there is a considerable amount of direct experimental data on neutral wind motions, and radio techniques appear to give values in agreement with these measurements. The significance of the radio data for the F-region is examined in some detail with respect to the little information which is available on neutral air motion in this region. Strong evidence is presented that the major cause of the movement of small irregularities in this region is electrodynamic. © 1968.