[Politically Correct]

Hmm. The article calls this “mystery giant lightning” in the title, but then goes on to explain exactly what is happening. I think there is not a mystery here.

No, there are still mysterys here.
Did you know that these are so energetic that anti-matter is produced and annihilated in the sprites?

Lots of other weird stuff that we don't yet understand going on in there.

[exDemMom]

They described the overall phenomena—they know what it is. The rest is just details. No mystery.