Solar flare is the proper term, sometimes connected with a sunspot, sometimes not. They can cause problems with electronics, mostly at the high latitudes as our magnetic field channels the particles to the north and south poles. As an amateur astronomer, I have more than passing interest, they're just damn pretty, when strong enough that I can see them through the light polution of Milwaukee. We use terms such as curtains, beams, searchlights, to describe the different effects. Something that may be interesting to try to model.