When a volcano erupts, it can spew a cloud of ash miles into the stratosphere. It makes for an impressive sight, and an even more impressive amount of sheer material — large eruptions can loft cubic miles of rock and ash skyward.
And, to add to the wow factor, the clouds sometimes spawn their own lightning. As the cloud swirls chaotically in its journey skyward, the jagged ash particles are rubbed against one another, causing static electricity to accumulate. Static electricity in nature