On September 18, 2016, Frankie Lucena of Cabo Rojo, Puerto Rico, photographed an enormous ‘A-bomb’ sprite over the Carribean Sea.
These rank as the largest type of sprite in both horizontal and vertical dimensions. And for a split-second, the sky lit up like this:
This type of sprite is often called ‘jellyfish’ or ‘A-bomb,’ and ranks as the largest type of sprite in both horizontal and vertical dimensions.
It consists of a bright halo approximately 85 km above Earth’s surface surrounding sprite elements with long tendrils reaching down as low as ~30 km above ground level.
This kind of sprite tends to be triggered by a very impulsive positive cloud-to-ground flash.
But curiously, Lucena did not observe an instigating lightning bolt, but, Instead, just before the sprite appeared, he recorded a bright point-like flash of light. Was it a cosmic ray hitting the camera?.
Or was the point-like flash a cloud-to-ground strike mostly eclipsed by intervening clouds?
Did Lucena photograph something new triggering a sprite? There is still much to learn in this mysterious field.