The real fairy kings of the skies are the elves, it turns out. This is the name given to doughnut-shaped bursts of light that appear higher but more briefly than sprites, decorating the ionosphere skies at a height of 90 km for less than a millisecond.
Alfred Chen at the National Cheng Kung University in Tainan, Taiwan, a member of the ISUAL team, says he is excited by his unexpected discovery of the large global elf population. Unlike the sprites, which "mainly congregate over continents, elves are found mostly over oceans," he says.
Elves, it seems, like it wet and warm. Wherever the sea surface temperature exceeded 26˚C, Chen found elves. "The warm ocean surface can provide the heat source needed to drive intense oceanic lightning with very high peak currents, which generate elves in the ionosphere," he says.