Gamma rays interaction with matter

TRANSIENT LUMINOUS EVENTS, TLEs

Figure 11. Transient Luminous Events in the atmosphere extending to 62 miles or 100 kms in height. Sprites only last for about 10 to 100 milliseconds, despite being dozens of miles in length. Sprites have been observed above every continent on the globe except for Antarctica. They happen with most frequency over the central USA around Tornado Alley. The deep red color is believed to be the result of the lightning interacting with nitrogen in the atmosphere. The phenomenon may also be accompanied by a large, rapidly expanding halo of light known as an Elve, but the two do not always occur at the same time. Sprites are so large that they have been spotted by cameras on the International Space Station, ISS which orbits the Earth around 250 miles above the planet's surface.

Launched to the International Space Station (ISS), the Atmosphere-Space Interactions Monitor (ASIM) package includes two cameras which can capture 12 frames per second, plus x- ray and gamma ray detectors. It will observe the strange electrical phenomena that occur above thunderstorms. Orbiting at an altitude of just over 400km, the ISS provides the perfect view of Earth's turbulent weather systems. The electrifying effects of storms are frequently observed from the space station. The Transient Luminous Events (TLEs) were first spotted in 1989. The phenomena were named sprites and elves because of their fleeting, mysterious nature [11].

These are different from lightning as pulses of an electric field that travels up. For the sprite, when the atmosphere gets thin, the electric field can get a discharge. Sprites appear milliseconds after a powerful cloud-to-ground lightning strike.
Elves are caused by the electromagnetic pulse that the strike produces. They are a brief, aurora-like expanding halo in the ionosphere. They occur too quickly to be spotted by the human eye and last less than one millisecond. They are thought to occur twice as often as sprites.
The blue jets as upward electrical discharges from cloud tops are not very well studied because they are very faint. They are not necessarily associated with lightning.
While elves are mainly spotted over warm ocean waters, sprites tend to occur over land. A normal summer thunderstorm is about 10 km wide. Sprites appear above mesoscale convective systems which storm complexes about 10 times larger.
Lighting happens so fast and is so dangerous that it is hard to get to the real inside physics. In the thin upper atmosphere, TLEs are larger and easier to measure and represent a window to the inside of lightning [11].

Figure 12. Blue jets. Source: NASA.

Figure 13. Sprite discharges from cloud tops in thunderstorms. Source: NASA.

Figure 14. Jellyfish sprites.

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