Why does it sometimes rain and thunder, and sometimes it doesn't?

Because thunder needs certain conditions when it rains:

When it rains, some clouds in the sky are positive and some are negative. When two kinds of clouds meet, they will emit lightning and a lot of heat, which will make the surrounding air heat and expand. Instantly heated and expanded air will push the surrounding air, causing strong explosion vibration and thunder.

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 the weather phenomenon of "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.

Extended data:

Generation of lightning:

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.

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