How did the red elves form?

"Red Elf" is one of several phenomena caused by lightning in recent years, and its possible causes are briefly described as follows: Generally, lightning originates from the bottom of negatively charged clouds and falls to the surface. Lightning occasionally comes from a large number of positive charges accumulated at the cloud top, so after lightning, the ionosphere and cloud top will generate a strong electric field, attracting electrons to move upward. In the process of movement, it will collide with gas molecules. If the generated electric field is strong enough and the surrounding air is thin enough, electrons can get quite high energy before colliding with air molecules. When an electron collides with an air molecule, it will hit an excited state, causing the molecule to emit light, resulting in a short-lived high-altitude luminescence phenomenon, such as a red elf. Theoretically, this phenomenon occurs at an altitude of 40 to 90 kilometers. The brightest red elf can be seen by the naked eye, but it has been unknown for a long time. The reason is that it happens after extremely bright cloud lightning, so the above phenomenon will not attract the attention of scientists in particular. The luminous time of the red elf usually lasts less than one thirtieth of a second, and the brightness is usually not very bright, so the probability of its appearance is quite low. Therefore, scientists must use a high-sensitivity camera to continuously record the sky above the thunderstorm cloud in order to record this short-lived luminous phenomenon at high altitude. 1994, Sentman and Wescott recorded the strange phenomenon of' blue jets' for the first time. They were accidentally photographed by a high-sensitivity camera when the plane flew over a strong storm in the sky to catch the red elves. From these photos, we can know that this light is ejected from the top of the clouds at the speed of 120 km per second. At present, researchers are trying to find a theory that can fully explain its causes.

More than 20 international organizations and groups have studied the phenomenon of red elves in different parts of the world. In addition to the famous NASA and the University of Minnesota, Skyfire, located in Colorado, USA, has also made great achievements in atmospheric physics research and red elf research. Skyfire has done a lot of detailed research on red elves and blue jets. There are also special personnel responsible for investigating and collecting information about red elves and blue jets around the world. At present, there is also a Red Elf research team in Taiwan Province Province, China, which is composed of the physics department of the National national cheng kung university and other academic groups, and has also made great achievements in the study of lightning in the upper atmosphere.