How is lightning formed?

Lightning is a discharge phenomenon in thunderstorm clouds. Thunderstorm clouds generally have two conditions, sufficient water vapor and strong convection. In winter, because the air is cold and dry, the solar radiation is weak, and convection is not easy to form in the air, so lightning is rare. But sometimes when the temperature is high in winter, it will form thunderstorm clouds, leading to lightning and rain and snow.

Convection is particularly strong, and it can also form hail, which will produce a weather phenomenon called "thunder in winter". Since the middle of 5438+ 10, the warm and humid air flow has been extremely strong, and the temperature is obviously high. On June 5438+04, the highest temperature reached 22. 1℃, the highest in the same period in history. On June 5438+07, the strong cold air in the north went south and the two met. It not only snowed, but also thundered. Knowing these reasons, it is not surprising that it thunders in winter.

As we all know, the lightning in thunderstorm season is the same as the ionization breakdown of insulating materials in high voltage electric field. In thunderstorm weather, the high-voltage electric field formed by charged clouds is very strong. Usually, this is the case when charged clouds discharge to the earth. Clouds have a high potential in the positively charged region, while the earth has a low potential in the negatively charged region.

Air is originally non-conductive, but under the action of strong electric field force, the outermost electrons of gas nucleus will be excited by electric field force to make a transition and form charged ions. The atoms that gain electrons are called negative ions, and the atoms that lose electrons are called positive ions. Under the action of electric field force, charged ions can form electron flow.

In addition, the electrons of the insulator are strongly influenced by the gravitational field of the nucleus, which can also be called the binding force of the nucleus on the electrons. In the general external electric field, the peripheral electrons are in a large inert state, and it is difficult to excite the orbit to become charged ions. If the applied electric field force exceeds the binding force of its insulator to the electron, that is, the excited state of the electron, then its insulator will form what we often call a breakdown state and participate in conduction.

Among natural substances, natural mica is the most conductive inert substance, followed by glass, ceramics, plastics and so on. Air is a general insulating medium, and the free inertia of electrons around the nucleus of pure single gas is also very strong. However, the composition of space gas is not pure, and it is also doped with other material particles or water molecules, which is easy to form ionic States formed under low electric field. Dielectric breakdown ionization conduction is a common technical term in electrotechnics.

In the face of the strong electric field formed in nature, the insulating medium formed by space gas is insignificant, and the voltage field of hundreds of millions of volts can easily excite electrons outside the gas core to become charged ions to participate in conduction. The breakdown of insulating medium is the ionic state of insulating substance, and the arc discharge phenomenon formed by high-voltage electric field is the optical radiation produced by the energy release formed after the electrons outside the core of insulating medium are excited freely.

Lightning is a plasma conduction state formed by extranuclear electrons of space gas excited by electric field, accompanied by optical radiation and thermal effect. Due to the action of light and thermal radiation, the temperature of the surrounding air rises sharply, leading to thermal expansion, which in turn pushes the air to form a shock wave, that is, the sound of thunderstorm we hear.

The greater the concentration of water molecules in the air, the more impurities there are, the greater the possibility of breakdown ionization by high-voltage electric field, and the higher the probability and intensity of lightning strike. The intensity of lightning electric field has two factors. First, the light radiation intensity of lightning and the decibel coefficient of thunderstorm are also related to the electric field intensity. The closer the charged cloud is to the ground, the greater the electric field intensity.

Secondly, the greater the charge of the charged cloud, the higher the electric field intensity, and the electric field intensity is also related to the speed of charge accumulation. The duration of electric field discharge is also related to the speed of cloud charge accumulation, which is what we usually call the range of lightning duration and brightness.

Thunderstorm lightning between clouds belongs to a strong high-voltage electric field composed of positive and negative charges between clouds. Under the action of electric field force, the light radiation and air shock wave effect produced by the collision of positive and negative charges formed after gas breakdown are similar to the phenomenon of positively charged cloud-to-ground discharge.

The more cloud charges accumulate, the greater the high-voltage electrostatic field force, the stronger the lightning radiation intensity and the decibel coefficient of thunderstorm shock wave sound. Usually we can judge the energy of lightning from the glow intensity of lightning and the decibel coefficient of thunderstorm sound. At the same distance, the stronger the glow of lightning, the greater the thermal radiation energy and the higher the magnetoelectric induction to metal conductors.

The spectrum emitted by lightning is in the range of ultraviolet to infrared, and it will also destroy power and communication equipment, forming a natural lightning disaster with strong magnetic field radiation. In view of the mechanism of lightning formation, we humans are still exploring, and it is difficult to crack the formation factors of spherical lightning.

In a word, there are still many unknown problems to be solved in many aspects of lightning formation. It is believed that with the continuous progress of science, people will constantly attack the forbidden zone of nature and discover many unknown quantities in our nature.

Extended data

(1) When it thunders and rains, it is forbidden to stay at the top of the mountain or high hills, and it is necessary to continue to push up and watch the rain scene. Don't hide under trees or telephone poles, and don't walk or stand in open fields. You should hide in a low-lying place as soon as possible, or try to find a room floor or a dry cave to hide.

② In thunderstorm weather, do not use umbrellas with metal handles, and take off glasses, watches and belts with metal frames. If you travel by bike, you should leave the bike as soon as possible and stay away from other metal objects to avoid being struck by lightning.

③ Don't go swimming, boating or fishing in rivers and lakes in thunderstorm weather.

(4) In lightning and stormy weather, if tourists rest in the hotel, they should immediately turn off the indoor TV, tape recorder, stereo, air conditioner and other electrical appliances to avoid using electricity. It's safer in the middle of the room when it thunders. Don't stay under the electric light, and don't lean against posts, walls, doors and windows, so as to avoid accidents caused by induced electricity when it thunders.

When lightning strikes, the traveling companion should take the patient to the hospital immediately. If breathing and heartbeat have stopped at that time, mouth-to-mouth resuscitation and chest massage should be carried out at the scene immediately, and on-site rescue should be actively carried out.

Don't rush to the hospital without rescue, otherwise it will delay the onset and lead to death. Sometimes, on the way to the hospital, we have to continue artificial respiration and chest massage. In addition, we should pay attention to keep patients warm. If you have mania, convulsions, convulsions and other mental symptoms, you should also do a cold compress on your head. For the part of electric burn, in the case of first aid, it is only necessary to keep it dry or bandage it.

During a thunderstorm, even if a lightning rod is installed, it is necessary to quickly unplug the indoor TV, refrigerator and antenna power supply to prevent unnecessary losses caused by space electromagnetic interference. In addition, judging from the formation and occurrence process of lightning, lightning accidents mostly occur in open fields, the tops of buildings, tall trees, rivers, lakes, ponds and wet areas.

References:

Thunder Baidu encyclopedia