Volcanic Lightning

Image by Martin Rietze

It is thought that friction between particles and gases cause potential differences that create the lightning displays. [**]

Via Wikipedia:

Upper-atmospheric lightning or upper-atmospheric discharge are terms sometimes used by researchers to refer to a family of short-lived electrical-breakdown phenomena that occur well above the altitudes of normal lightning and storm clouds. Upper-atmospheric lightning is believed to be electrically induced forms of optical fluorescence. The preferred usage is transient luminous event (TLE), because the various types of electrical-discharge phenomena in the upper atmosphere lack several characteristics of the more familiar tropospheric lightning.

There are several types of TLEs, the most common being sprites. Sprites are flashes of bright red light that occur above storm systems. C-sprites (short for “columniform sprites”) is the name given to vertical columns of red light. C-sprites exhibiting tendrils are sometimes called carrot sprites. Other types of TLEs include sprite halos, blue jets, gigantic jets, blue starters, and ELVES. ELVES (Emission of Light and Very Low Frequency perturbations due to Electromagnetic Pulse Sources) refers to a singular event which is commonly thought of as being plural. TLEs are secondary phenomena that occur in the upper atmosphere in association with underlying thunderstorm lightning.

TLEs generally last anywhere from less than a millisecond to more than 2 seconds. The first TLE was captured accidentally in a video recording in 1989. University of Minnesotaresearchers were waiting to record a rocket launch and pointed the camera at a distant thunderstorm. A TLE was later identified, appearing in only two frames of the film. TLEs have been captured by a variety of optical recording systems, with the total number of recent recorded events (early 2009) estimated at many tens-of-thousands. The global rate of TLE occurrence has been estimated from satellite (FORMOSAT-2) observations to be several million events per year

A map of where lightning strikes most across the globe

In this map, created using NASA satellite data, you can see in lurid detail where lightning struck Earth the most between 1995-2002. This historical information can give scientists clues about where it’s likely to strike again. And with tornado, monsoon, and hurricane seasons getting underway, you too might want to know where these ultra-hot bolts of electricity will slam out of the clouds. Here are some of the most up-to-date lightning maps.

NASA also has a map of lightning strikes that’s regularly updated, showing lightning strikes from 1998 to the present. The more up-to-date map is very similar to what you see above, except that it shows more intense activity in Argentina and South Africa.

Also, according to NASA, the greatest amount of lightning strikes are near the Catatumbo River in Venezuela (where there are 40,000 strikes every night, for most of the year), and a mountain town called Kifuka in the Democratic Republic of the Congo. You can see the dark regions signaling thousands of lightning strikes over these areas in the map above.

Over at the University of Washington in Seattle, Earth scientist Robert Holzworth is running an ongoing project to collect lighting strike data all over the globe. Using sensors all over the world, Holzworth and his colleagues analyze very low frequency (VLF) waves in the radio spectrum emitted by lightning. He creates maps and animated gifs showing the distribution of lightning in various areas, revealing where lightning is striking the most over time.

The upshot? Warmer areas over land tend to attract the most lightning. And the patterns seem to be quite predictable, so it’s fairly easy to plan trips to avoid areas where you might incur the wrath of Zeus. Of course, as the climate warms up over the next century, these maps may reveal a very different set of patterns.

Guided Lightning

Using an experimental apparatus reminiscent of a classic Frankenstein movie, French researchers have coaxed laboratory-generated lightning into striking the same place, not just twice, but over and over. This feat of electrical reorientation used femtosecond (one quadrillionth of a second) pulses of laser light to create a virtual lightning rod out of a column of ionized gas. This is the first time that these laser-induced atmospheric filaments were able to redirect an electrical discharge away from its intended target and guide it to a normally less-attractive electrode.

Turns out, lightning can strike the same spot twice (and many, many more times)!