1. Atmospheric ionization characteristics:

According to the ionization characteristics of the atmosphere, the atmosphere can be divided into the neutral layer, ionosphere and magnetosphere.

A. Neutral layer: The neutral layer refers to the atmosphere from the ground to about 60 kilometers. Under normal circumstances, there are fewer charged plasmids in this layer, which is mainly composed of neutral gases.

B. Ionosphere: Generally refers to the air layer from 60 km to about 500 km. Under the action of solar ultraviolet radiation, a large amount of air is ionized, producing a large number of electrons and positive ions. Reflecting radio waves makes long-distance radio communication possible. The ionosphere changes with the changes of day and night, seasons, solar activity, etc. In general, the number of positive ions in the ionosphere is greater than that of electrons, and the positive ions are mainly distributed at the bottom.

C. Magnetosphere: refers to the atmosphere above 500 kilometers. There are also electrons and positive ions in this layer, but the distribution is extremely uneven and extremely thin. At such a height, the movement of charged particles is mainly controlled by the earth's magnetic field lines, so it is called the magnetosphere.

2. Vertical distribution characteristics of temperature:

According to this characteristic, the atmosphere can be divided into five layers: troposphere, stratosphere, mesosphere, thermosphere, and exosphere.

A. Troposphere: From the ground to the air, it is about 12 kilometers (mid-latitudes), about 8 kilometers at the poles, and 17-18 kilometers at the equator. The main atmospheric phenomena occur in this layer, such as clouds, rain, fog, rainbows, wind, hail, thunderstorms, sandstorms, etc.

B. Stratosphere: From the top of the troposphere to 50 kilometers. The ozone layer is between 10-50 kilometers, with the highest concentration between 20-30 kilometers. The movement of this layer of atmosphere is mainly advection, and is safer for aircraft to fly in this layer, and generally no turbulence.

C. Mesosphere: The atmospheric layer between the top of the stratosphere and about 85 kilometers.

D. Thermosphere: The air layer from the top of the mesosphere to a distance of 250 kilometers (when the sun is quiet) or about 500 kilometers (when the sun is active). The air in this layer is highly ionized due to the strong ultraviolet radiation from the sun. The aurora near the North and South Poles appears in this layer.

E. Outer layer: generally refers to the atmospheric range beyond 500 kilometers.

3. (Wilson):Wilson hypothesis:

There is no complete theory that is recognized as impeccable. The Wilson hypothesis is considered to be more complete and often recommended. The following is an overview of this hypothesis:

According to a large number of scientific tests, the earth itself is a capacitor, usually carrying a stable negative charge of about 500,000 coulombs. There is a positively charged ionosphere above the earth, and a charged capacitor is formed between the two. The voltage between them is about 300KV, and the field strength is positive at the top and negative at the bottom.

When the air containing water vapor on the ground is heated by the hot ground and rises, or when the warmer humid air meets the cold air and is lifted, an upward airflow will be generated. When these water vapors rise, the temperature gradually drops to form raindrops and hail (called hydroids). These hydroids are polarized under the action of the earth's electrostatic field, with negative charges on the top and positive charges on the bottom. They fall faster than cloud droplets and ice crystals (these two are called cloud particles) under the action of gravity. Polarized hydroids collide with cloud particles during their fall. As a result of the collision, some of the cloud particles are captured by the hydroids, increasing the volume of the hydroids, while the other part is not captured and is bounced back. The rebounded cloud particles take away part of the positive charge at the front of the hydroids, making the hydroids negatively charged.

Water-formed objects fall quickly, while cloud particles fall slowly, so the particles with positive and negative charges gradually separate (this is called gravity separation). If they encounter an updraft, the cloud particles continue to rise, and the separation effect becomes more obvious. Finally, positively charged cloud particles are formed in the upper part of the cloud, while negatively charged water-formed objects are in the lower part of the cloud, or negatively charged water-formed objects fall to the ground in the form of rain or hail. Once the charged cloud layer described below is formed, the thundercloud space electric field is formed. The direction of the space electric field is consistent with the direction of the electric field between the ground and the ionosphere, both are positive at the top and negative at the bottom, thus strengthening the electric field strength of the atmosphere, making the polarization of water-formed objects in the atmosphere more severe. In the presence of updrafts, the gravity separation effect is further intensified, causing the thundercloud to develop faster.

From the above analysis, it seems that thunderclouds always have positive charges on the upper layer and negative charges on the lower layer. In fact, airflow does not just move up and down, but there are more complex movements. Therefore, the distribution of thundercloud charges is much more complicated than what is mentioned above. The test results of scientists show that when the earth is struck by lightning, most of the negative charges are discharged from the thundercloud to the earth, and a few are positive charges on the thundercloud. In multiple lightning strikes in a thundercloud, the last lightning strike is often the positive charge on the thundercloud that discharges to the earth. Observations have shown that lightning strikes with positive charges discharged to the earth appear to be particularly violent.

Collision Induction Hypothesis (Workman-Reynolds Hypothesis)

Ice crystal-graupel collision: In thunderstorm clouds, updrafts carrying supercooled water droplets (temperature below 0°C but not frozen) collide with ice crystals and graupel (hail embryos with a diameter of about 1 to 5 mm).

Effect of surface water film: At the moment of collision, the surface of the hailstone generates heat due to friction and forms an extremely thin liquid water film (about nanometer thickness).

Charge transfer: Negative ions (such as Cl⁻, HCO₃⁻) in the water film are adsorbed by the graupel, causing the graupel to be negatively charged and the ice crystals to be positively charged.

Gravity sorting: Lighter positively charged ice crystals are carried to the cloud top (10-15 km altitude) by rising air currents, while heavier negatively charged graupel settle to the cloud bottom (5-8 km altitude), forming charge stratification.

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