The storm’s timing only days after the autumn equinox is no accident. More geomagnetic storms occur in the weeks before and following Earth’s equinoxes.
Earth’s magnetosphere aligns with the sun’s magnetic field during equinoxes because the sun is squarely above the equator.
They are misaligned most of the year, so the magnetosphere partly deflects CMEs and reduces their effect.
Even a weak or indirect CME conflicts more directly with the Earth’s magnetosphere at equinox and produces geomagnetic activity.
