Is this cool or what? It's lightning within the Icelandic volcano whose name no-one but an Icelander can pronounce.
I actually hunted around the 'net to find out why volcanoes can generate their own lightning, but the discussions varied from "I dunno" to the idea that the eruptions cause mesocyclones, thus generating the conditions for lightning.
I'm guessing no-one has managed to get close enough to take the readings they need to solve the conundrum.
While a lot of people seem bent out of shape over this (my sister is stuck in Paris... whatever shall she do?) it provides an opportunity for all those clever engineers to create an ash-proof engine. Remember Dante's Peak with that yummy Pierce... ah, the helicopter? Or 1991 when Mt Pinatubo went up in the Philipines? How is it we still don't have a totally weather-proof engine? That aircraft are still so fragile? The peeps who develop an engine unaffected by ash clouds, or smoke, or ducks could probably name their price.
Maybe Virgin Galactic have the right idea and we should leave terrestrial airspace. Just pop up outside the atmosphere and then down again. I have visions of it...