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Elusive red sprites caught dancing above an Arizona thunderstorm

Sprite captured above a storm near Ajo, Ariz. (John Sirlin)

It is positively electric!

While I have seen photos of sprites before, I have never seen an example of one placed so perfectly above a mature thunderstorm. This photo from southern Arizona made me stop in my tracks and exclaim, “Wow!” Photographer John Sirlin likely had the same reaction, when he got to check this rare capture off his photo bucket list.

When Sirlin shared this image on Twitter he exclaimed, “Made my first attempt at capturing sprites up close last night near Ajo. Weather is just amazing sometimes!”

This is something we agree on!!

So what is a red sprite? Allow me to wave the geek flag while breaking down the incredible science behind this electrifying phenomenon.

In short, a red sprite is a large-scale electrical discharge that occurs above a thunderstorm. Yes, you heard that right, above a thunderstorm. If thunderstorms can tower up to 60,000 feet into the atmosphere, sprites can occur up to 300,000 feet into the atmosphere (we are talking a zone of about 31 to 56 miles above the ground). To put this into more perspective, that is reaching altitudes 10 times as high as the average airplane flies.

Red sprites typically develop in relation to positive lightning strikes within a cloud. Positive strikes are the stronger discharges within a thunderstorm. The National Weather Service provides a good explanation on what makes positive lightning strikes so lethal:

Since it originates in the upper levels of a storm, the amount of air it must burn through to reach the ground is usually much greater. Therefore, electric fields associated with positive Cloud-to-Ground (CG) strikes are typically much stronger than those associated with negative strikes. The flash duration is also longer with peak charge and potential up to ten times greater as compared to negative CG strikes; as much as 300,000 amperes and one billion volts!

Positive lightning strikes originate in the cirrus anvil. This is the higher part of the thunderstorm, where a significant positive charge resides. Sprites are so rare in part because they originate from positive strikes, plus the fact that positive lightning strikes make up only about 5 percent of lightning.

While sprites are an electrical discharge just like lightning, there is one main difference: Sprites are not nearly as hot as lightning. Sprites come from a cold plasma phenomenon, which means they do not have the hot temperature channels that typical lightning has (remember, at 50,000 degrees Fahrenheit, lightning is five times hotter than the sun). Sprite formation is more analogous to fluorescent tube discharges than lightning discharges.

To see and capture a sprite in action, the perfect conditions must be present: a clear view of a mature thunderstorm, positive cloud-to-ground-lightning strikes and a pitch-black night-sky.

Sirlin found that sweet spot over Arizona earlier this week, and the results speak for themselves!

Weather is awesome. #cwgpicoftheweek