On the World-Wide Disturbance in F2-Region

抄録

The world-wide patterns of the F2-region disturbance and their development process with the geomagnetic storm-time were examined with the comprehensive world-wide data of F2-layer.
The average disturbance in f⁰F2 during the main phase of the associated magnetic storm, so-called D (f⁰F2), was derived with respect to geomagnetic latitude and local-time, and it was separated into the Dst (f⁰F2) and Ds (f⁰F2) component. It will be shown in this analysis these two components play an important role in the ionospheric storms, and not only their range, but also their phase are controlled by the magnetic activity.
The average development course of the ionospheric storm and the mode of the Ds (f⁰F2), changing regularly with storm-time, were studied. The phase of the Ds (f⁰F2) during the active stage of magnetic storm is almost uniquely dependent upon local-time, but after the activation ceases, the pattern of the disturbance moves together with the rotating earth.
Detailed analysis was made on the progressive aspects of the individual disturbances in the northern hemisphere accompanied with some typical severe magnetic storms.