Sprite Lightning Storm

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

The Epicenter of Sprite Alley

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

Jellyfish Sprites over Oklahoma

May 25, 2018: Last night, a swarm of luminous jellyfish appeared over Oklahoma. “A swarm of jellyfish sprites, that is,” says Paul Smith, who photographed them rising above an intense thunderstorm near Oklahoma City:

“The sprites were about 80 miles away from me,” says Smith. “At that distance I could see over the tops of the storm cells where the jellyfish appear. I’ve photographed many sprites from 200 to 300 miles away. These, however, were unusually nearby, and they are my best pictures yet.”

Sprites are an exotic form of upward directed lightning. Although the forms have been seen for at least a century, many scientists did not believe they existed until after 1989 when sprites were photographed by cameras onboard the space shuttle. Now “sprite chasers” like Smith routinely photograph them from their own homes.

“I have been recording sprites since last summer when I accidentally caught a few during the Perseid meteor shower,” says Smith. “I have a couple of hundred events on camera now and I am out almost every night there are storms in my vicinity. This month I have driven for five hours some nights trying to find a clear view over active cells.”


The blue pushpin is Smith’s location; the arrow points to the sprites he saw on May 24, 2018.

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. Already this year we have received reports of sprites and their stronger cousins, Gigantic Jets, from Texas to Nebraska. And summer thunderstorm season isn’t even fully underway yet.

Some researchers think that sprites may be linked to cosmic rays: Subatomic particles from deep space strike the top of Earth’s atmosphere, producing secondary electrons that trigger the upward bolts. If this is true, then sprites could multiply in the months and years ahead as cosmic rays intensify due to the decline of the solar cycle. More sprite images may be found on Paul Smith’s Facebook page.

Realtime Sprite Photo Gallery

Giant ‘ELVE’ Appears over Europe

On April 2nd, high above a thunderstorm in the Czech republic, an enormous ring of light appeared in the night sky. Using a low-light video camera, amateur astronomer Martin Popek of Nýdek photographed the 300 km-wide donut hovering near the edge of space:

“It appeared for just a split second alongside the constellation Orion” says Popek.

This is an example of an ELVE (Emissions of Light and Very Low Frequency Perturbations due to Electromagnetic Pulse Sources). First seen by cameras on the space shuttle in 1990, ELVEs appear when a pulse of electromagnetic radiation from cloud-to-ground lightning propagates up toward space and hits the base of Earth’s ionosphere. A faint ring of deep-red light marks the broad ‘spot’ where the EMP hits.

“For this to happen, the lightning needs to be very strong–typically 150-350 kilo-Ampères,” says Oscar van der Velde, a member of the Lightning Research Group at the Universitat Politècnica de Catalunya. “For comparison, normal cloud-to-ground flashes only reach 10-30 kA.”

ELVEs often appear alongside red sprites, which are also sparked by strong lightning. Indeed, Popek’s camera caught a cluster of sprites dancing nearby.

ELVEs are elusive–and that’s an understatement. Blinking in and out of existence in only 1/1000th of a second, they are completely invisible to the human eye. For comparison, red sprites tend to last for hundredths of a second and regular lightning can scintillate for a second or more. Their brevity explains why ELVEs are a more recent discovery than other lightning-related phenomenon. Learn more about the history and physics of ELVEs here and here.

Realtime Sprite Photo Gallery

Mesospheric Bore

Nov. 29, 2016: This month, a lot is happening in the mesosphere. The mesosphere is a layer of Earth’s atmosphere above the stratosphere; it is the realm of sprites, noctilucent clouds (NLCs), and airglow. Starting on Nov. 17th, NASA’s AIM spacecraft spotted bright noctilucent clouds forming in the mesosphere above Antarctica. Then, in an apparently unrelated development on Nov. 24th, the normal dome of airglow over China split in two. Xiao Shuai photographed the event from Mount Balang in Sichuan:

This is called a “mesospheric bore”–and not because it’s dull.  A bore is a type of atmospheric wave with deep ripples at its leading edge.  Indeed, you can see the ripples in Shuai’s photo separating the zone of airglow from clear sky.

Bores fall into the category of “gravity waves”—so called because gravity acts as the restoring force essential to wave motion. Analogy: Boats in water. When a boat goes tearing across a lake, water in front of the boat is pushed upward. Gravity pulls the water back down again and this sets up a wave.

In this case, instead of water, rarefied air is the medium through which the wave propagates.  The sudden boundary in the airglow layer is probably akin to a hydraulic jump.  But what created the disturbance in the first place?  (What is the ‘boat’?) No one knows.

“There may be updates in the coming days as scientists from NASA and the Chinese Academy of Science check data from satellites to learn more about this event,” says Jeff Dai, who has been helping Xiao Shuai process and communicate his extraordinary images. “Also, we encourage other photographers from Thailand, Myanmar, Bangladesh and India to submit their images of the wave.”

Realtime Space Weather Photo Gallery

Sprites above Hurricane Matthew

by Dr. Tony Phillips (Spaceweather.com)

Oct. 2, 2016: On Oct. 1st, Earth weather met space weather above Hurricane Matthew.  As the giant storm system was approaching the Greater Antilles, Frankie Lucena of Puerto Rico photographed red sprites shooting up from the thunderclouds:

Sprites are a strange and beautiful form of lightning that shoot up from the tops of electrical storms. They reach all the way up to the edge of space alongside meteors, auroras, and noctilucent clouds. Some researchers believe cosmic rays help trigger sprites, making them a  true space weather phenomenon.

Seeing sprites above a hurricane is rare. Many hurricanes don’t even have regular lightning because the storms lack a key ingredient for electrical activity: vertical winds. (For more information read the Science@NASA article “Electric Hurricanes.”) But Matthew is not a typical hurricane.  It’s one of the most powerful in recent years, briefly reaching Category 5 at about the time Lucena photographed the sprites.  Perhaps extra-strong winds in the vicinity of the storm set the stage for upward-reaching bolts.

Sprite photographers across the Caribbean and the southeastern USA should be alert for more as the storm system approaches the mainland: observing tips.

Realtime Sprite Photo Gallery

Space Lightning Over China

On Aug. 13th in China, photographer Phebe Pan was photographing the night sky, hoping to catch a Perseid meteor. Instead, he witnessed a spectacular bolt of “space lightning.” Working atop Shi Keng Kong, the highest mountain peak in the Guangdong province, “I was using a fisheye lens to capture as much of the sky as possible,” says Pan. “Suddenly we saw a flash of blue and purple ejected from the top of a nearby thundercloud. It just looked like a tree with branches, and grew up very fast. So awesome!”

“It just looked like a tree with branches, and grew up very fast,” says Pan. “It lasted just less than one second. So awesome!”

Oscar van der Velde, a member of the Lightning Research Group at the Universitat Politècnica de Catalunya, explains what Pan saw: “This is a very lucky capture of a gigantic jet. It’s the first time I’ve seen one captured using a fisheye lens!”

Think of them as sprites on steroids: Gigantic jets are lightning-like discharges that spring from the tops of thunderstorms, reaching all the way to the ionosphere more than 50 miles overhead. They’re enormous and powerful.

“Gigantic jets are much more rare than sprites,” says van der Velde. “While sprites were discovered in 1989 and have since been photographed by the thousands, it was not until 2001-2002 that gigantic jets were first recorded from Puerto Rico and Taiwan.” Only a few dozen gigantic jets have ever been seen.

Like their cousins the sprites, gigantic jets reach all the way up to the edge of space alongside meteors, noctilucent clouds, and some auroras. This means they are a true space weather phenomenon. Indeed, some researchers believe cosmic rays help trigger these exotic forms of lightning, but the link is controversial.

Realtime Sprite Photo Gallery

Rare Blue Starter

by Dr. Tony Phillips (this article originally appeared on Spaceweather.com)

We all know what comes out of the bottom of thunderstorms: lightning bolts. But on Oct. 20th, Thomas Ashcraft of New Mexico saw something coming out of the top. “I captured a form of a transient luminous event called a ‘blue starter’ shooting up from the top of a thunderstorm cloud,” he says. “Blue starters are rarely captured from ground level and there are hardly any specimens on the internet.”

Lightning scientist Oscar van der Velde explains this phenomenon: “A blue starter is an electric streamer discharge coming out of the top of a thundercloud, fanning out and reaching up to the stratosphere as high as 26 km altitude. First reported by UAF scientists Wescott and Sentman in 1995/1996, they were found to be different from blue jets, which reach 35-40 km height.”

“Since then, there have been very few reports of blue starters,” continues van der Velde. “It seems that unusual physical circumstances may be required to produce them. Also, geometry can prevent people from seeing blue starters when a cloud is nearby because the underbody of the cloud can block their view. At larger distances the blue/violet light does not make it to the observer due to scattering.”

Blue starters and blue jets are cousins of sprites, another form of exotic lightning that shoots up instead of down. Sprites, however, are more frequently observed. Check them out in the realtime photo gallery:

Realtime Sprite Photo Gallery