This is a soft X-ray image of the sun from the Yohkoh SXT telescope. CMEs are borne by the solar wind and their interaction with Earth's magnetosphere is a major cause of geomagnetic storms. I am interested in learning about the interior of the solid Earth by studying the electric currents that are induced in Earth's lower crust and upper mantle by geomagnetic storm events. It all starts inside the sun. A transient disturbance is passed though the loop.
Eddy currents circulate in the conductive ground in response to the disturbance.
The eddy currents, in turn, generate a secondary magnetic field that is modulated by the subsurface electrical conductivity distribution. The secondary field diffuses through the earth long after the transmitter has been turned off. The transient flux waveforms are digitized and stored, and then subjected to inverse analysis which generates models of subsurface electrical conductivity. So far, so good. Laboratory data on electrical properties of rocks come in useful, while other geophysical information can further reduce ambiguities in the interpretation.