抄録
The unequal occurrence frequency of positive and negative geomagnetic bays at various places over the world will be attributable to the condition that most cases of geomagnetic bays are polar elementary storms, especially negative ones, the typical or idealized disturbance field of which is represented by an overhead current-system composed of an intense westward current of narrow longitudinal width along the auroral zone and the counter current flow over the whole remaining part of the world. This result must be carefully taken into consideration when the average current-system for geomagnetic bays is dealt with. The systematic rotation sense of the disturbing force vectors of bays observed everywhere in middle latitudes, clockwise in the forenoon and counter-clockwise in the afternoon, is a result of the systematic progressive change in the overhead current-system during the course of bays. Some other important problems to be examined are also suggested.
