Relationship between the Magnetic Flux of Solar Eruptions and the Ap- Index of Geomagnetic Storms . ... In the extreme-ultraviolent range, CMEs are accompanied by dimmings and bright post-eruption arcades. ... Solar Phys. 282, 175, 2013) revealed that the summarized unsigned magnetic flux of dimming and arcades at the photospheric level ? ... and another geomagnetic index Ap . ... Figure 1: Dependence of the geomagnetic storm Ap-index on the magnetic flux of solar eruptions . ...