Sprites And Elves Haunt Nighttime Thunderclouds

Red sprites captured by astronauts aboard the space station on April 30, 2012 while they passed over Myanmar (Burma) and just north of Malaysia. The white glow is lighting inside a thundercloud. Credit: NASA

Ever since I learned about sprites, the bizarre electric discharges associated with thunderstorms that shoot up in the sky instead of down to the ground, I’ve wanted to see one. July’s a great month to be on the look out for these short-lived red flashes that come and go in milliseconds. They occur some 50 miles above active thunderstorms – about the same level as noctilucent clouds – and extend upward from 12 to 19 miles. The name refers to the phenomenon’s spooky, elusive nature like the folkloric fairies of old.

Red sprite with blue tendrils extending downward. Click to see a short movie of a sprite.  Credit: Univ. of Alaska, Fairbanks

Dr. Dave Sentman of the University of Alaska, Fairbanks is one among a small group of researchers who have been studying these mysterious bursts of colored light. Although no one’s sure what sprites really are or what causes them, these scientists have learned that sprites contain a great deal of energy.

They’re associated with positive cloud-to-ground lightning discharges but unlike lightning, they direct their energy toward outer space into Earth’s ionosphere. In addition to light, sprites also radiate radio waves and even pulses of high-energy gamma rays.

Sprites are members of a family of energetic, high-altitude phenomena occurring during thunderstorms. Credit: Abestrobi / Wiki

Sentman and other scientists flew above thunderclouds to study sprites up close. Seen nearly head-on, he describes them as colorless and about as bright as the aurora; younger members of the team with younger eyes spied the red color.

Sprites aren’t the only recently discovered electrical discharge to pop up in thunderstorms. Similar phenomena called elves, blue jets and halos have also been recorded, though sprites are more common and likely to be observed.

So how do you see one? Well, you could get lucky and find yourself in an airplane flying between storm clouds at 35,000 feet on a cross-country vacation. If so, turn off the overhead light and squeeze your face up against the window with your eyes on the stars above.

For ground viewing, you’ll need a night-time thunderstorm but not one that covers the sky and blocks the sprites from view. Best is a clear, starry sky with a line of thunderstorms crackling away along a distant horizon. That way you have a line of sight view across the cloud tops. The next time you notice flashes of lightning in an otherwise cloudless night sky, see what direction they’re coming from and drive to where you have an open view of that horizon.

A thunderhead cloud is lit from within by lightning a couple years back. Note the stars above it.  I didn’t see any sprites that night. Photo: Bob King

To improve your chances, avoid observing during twilight and in bright moonlight. You need dark skies and dark-adapted eyes. Fix your gaze a short distance above the line of thunderclouds while ignoring the bright flashes of lightning.

You can use a piece of cardboard or the roof of your car to help block the storm if it’s too much of a distraction.

Not all thunderstorms produce sprites, elves and the rest, so you’ll need patience to see one. The more you’re out under the stars, the better your chances.

I hope the fairies will guide you and me both to our first sprite this summer. You can learn more about sprites HERE and HERE.

6 Responses

    1. astrobob

      Thanks Mike! I set up camera on tripod, found the optimum exposure and hoped a frame or two would capture the occasional lightning I was seeing with my eyes. I only got a few with lightning in them.

  1. Otha H Vaughan Jr

    Here is a Brief History for the Discovery of Sprites:
    Historical Background for Sprites
    Eyewitnesses have reporten luninous events above thunderstorms
    for over 100 years, but no detail documentation, these events were
    given little credence by the atmospheric electricity community.
    Strong evidence presented itself in July 1989 when scientists in
    Minnesota were testing a low light level TV camera for an upcoming
    sounding rocket launch. By accident the camera pointed to observe
    stars captured two illuminated columns extending into the stratosphere
    above a distant thunderstorm that was below the earth’s horizon
    about 224 miles away.
    Prior to this event a U-2 pilot in 1976 reported that he had seen a lightning
    bolt move up from the top of a thunderstorm and go to at least 100,000
    feet above his altitude. In addition retired military and civilian pilots had
    reported they had seen unusual lightning events during their flying careers.
    The U-2 event , the pilots reports, and Minnesota observation led Otha H
    Vaughan, Dr. Richard Blakeslee of NASA MSFC as well as his University
    lightning researchers Dr William Boeck, Niagara University, New York, Dr
    Bernard Vonnegut at State University of New York at Albany and Dr. Marx
    Brook of the New Mexico Institute of Mining and Technology to propose
    an observational program in an attempt to record these type of events from
    the Space Shuttle.
    The observational program was called the Mesoscale Lightning
    Observation Experiment (MLE). The first good Sprite event was captured on
    video was from a thunderstorm during the STS-34 October 1989 flight as the
    shuttle’s payload bay camera recorded images as the shuttle passed near
    Australia on its orbit.

    For more details check out my Web site: http:www.knology.net/~skeetv/

    The Role of the Space Shuttle Videotapes in the Dicovery of Sprites, Jets,
    and Elves

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