Comment by fsloth

Geomagnetically induced currents generally become a problem over hundreds of kilometers. Long range electricity transmission lines are the main worry I believe and solar storm events have knocked off large grids occasionally.

I have no idea what the correlation is between particle flux (the metric reported here) and actual geomagnetic variation which induces the current (varying magnetic field causes voltage). Basically the charged particles zoom past earth, then loop back from the magnetotail towards the poles. The magnetohydrodynamics cause effects large enough to modulate the magnetic field on earths surface.

”We have this long conducting loop” is the issue. The Earth is one component of the loop.