"For me, personally, these shots are special," says Spinner, who has been monitoring sprites in Europe for more than 7 years. "Although three jellyfish sprites in one evening is nothing unusual for a strong thunderstorm, color videos of sprites in HD or 4K quality haven't been possible for very long. The Sony A7s came on the market only a few years ago."
Cosmic rays may be helping Spinner capture such images. The rays are intensifying because of Solar Minimum. During this phase of the solar cycle, radiation from deep space penetrates the sun's weakening magnetic defenses and enters Earth's atmosphere more than usual. Some researchers believe that cosmic rays provide the ionizing "spark" that triggers sprites.
Spinner knows where to point his cameras thanks, in part, to live lightning maps published by Blitzortung.org. Mesoscale convective systems with strong lightning tend to produce sprites as well. It helps to be at least a hundred kilometers away from a storm in order to see over the top of the thunderhead. "Even if you know exactly where the thunderstorms are and where the sprites might occur, however, it is always a surprise what kind of spectacle nature actually offers you," says Spinner.