June 10, 2018: This weekend, a powerful mesoscale convective system (MSC) of thunderstorms over central Europe produced a furious outburst of sprites. “It was unreal,” says Martin Popek of Nýdek, Czechia, a veteran photographer of the upward directed bolts. “I recorded more than 250 sprites in only 4.5 hours of observation! That’s nearly as many as I typically see in the entire summer thunderstorm season.”

Many of the sprites during the outburst looked like this:

This is a jellyfish sprite–so called because it resembles the eponymous sea creature. Jellyfish sprites are typically very large, stretching as much as 50 km between the tops of their heads to the tips of their tentacles below. “Regular jellyfish sprites are associated with very strong positive cloud-to-ground lightning strokes in the underlying convective storms,” notes lightning scientist Oscar van der Velde of the Technical University of Catalonia, Spain.

However, not all of the jellyfish were regular. Some were “decapitated”–without heads. “I recorded about 20 sets of tentacles only,” says Popek. Here is one example of many:

“In my experience, this is quite rare,” he adds.

“It is rare,” agrees van der Velde. “We don’t know why they sometimes look like this.” He speculates that atmospheric waves called “gravity waves” sometimes interfere with the normal formation of jellyfish, leaving them headless. “Mesospheric gravity waves likely help focus the electric field to trigger downward streamers,” he says. “But note that sprite morphology is not fully understood–not even for regular jellyfish. We have a lot to learn.”

Another observer in the Czech Republic, Daniel Ščerba-Elza, also photographed the display. “It was extremely active,” says Ščerba-Elza. “I recorded about 69 sprites, much more than usual. The storms were about 250 – 300 km away in Austria and Hungary. This is a good distance because it allows you to see over the tops of the thunderheads.” He made a summary video of the outburst.

Such an outburst before summer even begins may be a good omen for sprite photographers as thunderstorm season gains steam. Stay tuned for more sightings.

Realtime Sprite Photo Gallery

June 2, 2018: Oklahoma is a good place to see sprites. “I photograph them often,” says Paul Smith of Edmond OK. “Here are some examples from May 30th flashing above fast-moving storms in the Oklahoma panhandle.”

“Venus is the bright ‘star’ just behind the windmill,” he adds.

Oklahoma is the epicenter of a region that we call “Sprite Alley,” a corridor stretching across the US Great Plains where intense thunderstorms produce lots of upward directed lightning–a.k.a. “sprites.”

“I have been recording sprites since last summer when I accidentally caught a few during the Perseid meteor shower,” says Smith. “I now have a couple of hundred events on camera and I am out almost every night there are storms in my vicinity.”

The blue pushpin in the satellite weather map, above, shows Smith’s location. The blue arrow points to the storm cell that produced the sprites.

People have been seeing sprites since at least the 19th century, but those early reports were often met with skepticism. Sprites entered the mainstream in 1989 when researchers from the University of Minnesota finally captured them on film. Subsequent video footage from the space shuttle cemented their status as an authentic physical phenomenon.

In recent years, citizen scientists have been photographing sprites in record numbers. But why? It could be a result of raised awareness. More photographers know about sprites, so naturally more sprite photos are taken.  There might also be a real increase in sprite activity. Some researchers think that sprites are linked to cosmic rays: Subatomic particles from deep space strike the top of Earth’s atmosphere, producing secondary electrons that trigger the upward bolts. Indeed, cosmic rays are now intensifying due to the decline of the solar cycle.

It all adds up to more sprites over Oklahoma. More examples may be found on Paul Smith’s Facebook page.

Realtime Sprite Photo Gallery