Lightning Sprites, Elves, and Trolls: Magic in the Skies

How to see a red sprite

August 24, 2020
Weather Sprite

Ever heard of lightning’s stranger cousins—red sprites, blue jets, elves, trolls, and gnomes? No, these brilliant lights are not fairy tales; they are a colorful community of lightning flashes that occur high above large thunderstorms.

For over a century, these flashes of lightning that shot up from storm clouds, like stories of rains of toads, were dismissed as fiction. Even when respectable pilots or scientists (including CTR Wilson, a Nobel Prize winning physicist) described them, the scientific community ignored the events. Then, in 1989, something awkward happened. University of Minnesota scientists actually caught the so-called “sprites” on film.

Oops!

Since then, scientists have been studying not just the lightning that crashes down from thunderstorms, but also these colorful flashes that stream up towards space. Electricity soars up to the electrically charged ionosphere, just as it plunges down towards the earth.

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Image: Red Sprites over the English Channel, 2017. APOD/NASA.
 
Together, these flashy events are labeled Transient Luminous Events or TLEs. Individual light flashes have much more playful names. The original lights were named sprites because they were mysterious, the other lights received fairy names because scientists can have a sense of humor.

Different TLEs flash at different levels in the sky. SOURCE: Wikipedia
Click image to expand

So, if you look high in the sky, well above over the thunderstorms, what can you see?

  • Sprites—The most common TLE is a flash of red light directly above large thunderstorms. Sprites flash a fraction of a second after strong lightning strokes, soaring up almost 60 miles high. They are most frequently seen in the Midwest.
  • Blue Jets—A blue jet is a dim blue light that rises like a quick puff of smoke above heavy hailstorms. They are quite rare and usually can only be seen from airplanes.
  • Elves—Elves are brief disks of dim light that appear around 60 miles high in the atmosphere. Actually, the name is an abbreviation of the disk’s real name—Emissions of Light and Very low frequency from EMP Sources.
  • Trolls—These red spots pop near cloud tops after the flash of an extremely strong red sprite. Like Elves, Trolls are an abbreviation: Transient Red Optical Luminous Lineament.
  • Gnomes—The tiniest and quickest flashes are gnomes. They are small white spikes of light that flash for a microsecond from the top of a large thundercloud’s anvil.

Image: Look over the top of thunderstorms to see sprites and other flashes. NASA.

Here’s an interesting fact: Lightning sprites and TLEs do not happen in our normal thunderstorms with rain clouds. All of Earth weather occurs in the troposphere (4 to 12 miles above us). Rather, these flashes happen in the Earth’s mesosphere, up to 50 miles high in the sky. 

How to See a Red Sprite

A red sprite is the easiest TLE to see, but you need to be aware of the conditions that make a lightning sprite visible.

  1. You’ll need a strong thunderstorm. Sprites pop up everywhere and anywhere powerful thundstorms occur, especially in summertime.
  2. The thunderstorms needs to during the nighttime. Of course, the skies need to be very dark and clear. Avoid bright moonlight. 
  3. The storm should be in the distance (100 to 200 miles away), so clouds do not block the sky.  Ideally, the storm is moving out of the region or along a distant horizon so that you can see above the cloud tops. Use weather radar to track a storm.
  4. Give your eyes 20 minutes to adapt to darkness. And then try to keep your eyes above the clouds (not on the clouds) while ignoring the lightning flashes. Sprites pop into view roughly once for every 200 lightning strokes.

Note: It may be difficult to capture a sprite on camera as the flash is fleeting. 

Watch this gorgeous video by Paul M Smith which shows Red Sprite lightning from the 2019 storm season in Oklahoma.

Next time you see a thunderstorm, look above it. You may see a fairyland!

About This Blog

The column, “Weather Whispers,” is authored by James Garriss and Evelyn Browning Garriss, historical climatologists and weather addicts!  Whether you enjoy the science of weather or the fascinating folklore or just fun weather phenomena, it’s probably covered by these weather watchers!

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