Seasonal Dependence of SC-Field in Middle and Low Latitudes

抄録

An analysis of world-wide geomagnetic field-change for eight SC's during IGY indicates that the uniform northward external magnetic field for SC in middle and low latitudes shows a systematic seasonal dependence, namely, the uniform external magnetic field inclines towards the sunlit side in the summer hemisphere, and towards the night side in winter. This systematic seasonal dependence of the SC-field may be explained as due to the geometrical relation between the incident direction of the solar wind and the geomagnetic dipole axis.