At https://spaceweather.com (June 1st 2020) we have a short video captured over New Mexico and Texas – a magnificent jelly fish sprite followed by a green after glow …
… green ghosts were discovered just a few years ago by a storm chaser. Green is a colour commonly seen in aurora and air glow, two upper atmospheric phenomena that get the hue from excited atoms of oxygen. The same explanation may be true of green ghosts – excited by the sprites (atmospheric lightning). Sprites are common in the USA during summer electrical storms.
For the full story go to https://spaceweatherarchive.com/2020/05/31/introducing-the-green-ghost/