Lightning is a strong discharge phenomenon between clouds, between clouds and the ground, or between different parts of clouds (usually in cumulonimbus clouds).
Cumulonimbus clouds usually produce electric charges, with negative charges at the bottom and positive charges at the top, and the ground also produces positive charges, which move with the clouds. Positive and negative charges attract each other, but air is not a good conductor. Positive charges rush to tree tops, hills, tall buildings and even human bodies in an attempt to meet negatively charged clouds; The negatively charged dendritic antenna extends downward, and the farther it extends, the closer it is to the ground. Finally, the positive and negative charges finally overcome the air barrier and connect. A huge current rushed from the ground to the clouds along the conductive path, producing a bright flash. The length of lightning may be only a few hundred meters (the shortest is 100 meters), but the longest is also several kilometers. The temperature of lightning varies from 17000 degrees Celsius to 28000 degrees Celsius, which is 3~5 times the surface temperature of the sun. The extreme heat of lightning caused the air along the way to expand violently. Air moves very fast, so waves are formed and sounds are made. When lightning approaches, you hear a sharp crack; If it's far away, you hear rumbling. You can start the stopwatch after seeing lightning, press the stopwatch to stop when you hear thunder, and then multiply the number of seconds by 0.3 (the speed of sound is about 340m/s) to get a general idea of how many kilometers the lightning is away from you.
If we apply a high voltage between two electrodes, they will be closer together. When two electrodes are close to a certain distance, there will be an electric spark between them, which is called "arc discharge". The lightning generated by thunderstorm clouds is very similar to the arc discharge mentioned above, except that lightning is fleeting, but the spark between electrodes can exist for a long time. Because the high voltage between the two electrodes can be artificially maintained for a long time, it is difficult to replenish the charge in the thunderstorm cloud immediately after discharge. When the accumulated charge reaches a certain amount, lightning in hail clouds will occur between different parts of the cloud or between the cloud and the ground.
[1] formed a strong electric field. The average electric field intensity can reach several thousand volts/cm, and it can be as high as 10000 volts/cm in some areas. Such a strong electric field is enough to break through the atmosphere inside and outside the cloud, so dazzling flashes are excited between the cloud and the ground or between different parts of the cloud and between different clouds. This is what people often say about lightning. Seeing lightning with the naked eye is very complicated. When the thunderstorm cloud moves somewhere, the middle and lower part of the cloud is the center of strong negative charge, and the underlying surface opposite the cloud bottom becomes the center of positive charge, forming a strong electric field between the cloud bottom and the ground. With more and more charges and stronger electric field, a section of air column with strong atmospheric ionization first appears at the bottom of the cloud, which is called cascade leader. This ionized gas column extends to the ground step by step. The leader of each step is a dim light beam with a diameter of about 5 meters, a length of 50 meters and a current of about 100 ampere. It extends to the ground step by step at an average high speed of about 150000 m/s. When it was about 5-50 meters from the ground, the ground suddenly counterattacked. The channel of counterattack is from the ground to the bottom of the cloud, along. The return stroke galloped from the ground to the bottom of the cloud at a higher speed of 50,000 km/s, emitting an extremely bright beam, which lasted for 40 microseconds, and the current passed through exceeded 10000 amps. This was the first lightning strike. A few seconds later, a dim light beam from the cloud, carrying huge current, flew to the ground along the path of the first lightning strike. This is the so-called direct channeling pilot. When it is about 5-50 meters away from the ground, the ground strikes back again, forming a bright beam, which is the second lightning strike. Then, like the second time, there were the third and fourth lightning strikes. Usually 3-4 lightning strikes constitute a lightning process. A lightning process lasts about 0.25 seconds. In this short time, a huge amount of electric energy will be released in the narrow lightning channel, which will form a strong explosion, produce shock waves, and then form sound waves to spread around. Is this thunder or "thunder"
Edit the chemical reaction that occurred during this lightning stroke.
1. When struck by lightning, it can change the chemical bond of oxygen in the atmosphere and produce a very small amount of ozone; 2. Oxygen and nitrogen can combine to produce nitric oxide, which is an important form of natural nitrogen fixation. 3.3H2+N2=2NH3 The temperature of lightning varies from 17000 degrees Celsius to 28000 degrees Celsius, which is 3-5 times of the surface temperature of the sun. The extreme heat of lightning caused the air along the way to expand violently. Air moves very fast, so waves are formed and sounds are made.
lightning
What has been studied in detail is linear lightning, so let's take it as an example to talk about the structure of lightning. Lightning is a pulse discharge phenomenon in the atmosphere. Lightning consists of multiple discharge pulses, and the interval between these pulses is very short, only a few hundredths of a second. Pulse after pulse, and the subsequent pulse follows the path of the first pulse. Now it has been clearly studied that each discharge pulse consists of a "leader" and a "counter-attack". Before the first discharge pulse bursts, there is a preparation stage-"step-by-step" discharge process: under the impetus of strong electric field, the free charge in the cloud moves quickly to the ground. During the movement, electrons collide with air molecules, which makes the air slightly ionized and glow. The leader of the first discharge pulse spreads down step by step, like a glowing tongue. At first, the smooth tongue was only a dozen meters long. After a few thousandths of a second or even less, the smooth tongue disappeared. Then, on the same paragraph, a longer light tongue (about 30 meters long) appeared and disappeared in the blink of an eye; Then a longer smooth tongue appeared ... the smooth tongue approached the ground step by step in a "gnawing" way. After many times of discharge-disappearance, the smooth tongue finally landed. Because the leader of the first discharge pulse propagates from the cloud to the ground step by step, it is called "step leader". On the channel of the light tongue, the air has been strongly ionized, and its conductivity has been greatly increased. The process of continuous ionization of air only occurs in a narrow channel, so the current intensity is very high. When the first pilot, the ladder pilot, reached the ground, a large amount of charge immediately flowed from the ground to the cloud through the highly ionized air channel. This current is so strong that the airway fires and a winding and slender light beam appears. This stage is called the "counter-offensive" stage, and also called the "main force expulsion" stage. The ladder pilot and the first counterattack constitute the whole process of the first pulse discharge, which lasts only one hundredth of a second. After the first pulse discharge process, only a very short time (4 seconds) passed, and the second pulse discharge process occurred. The second pulse also starts from the pilot and ends at the return trip. However, after the first pulse discharge, "the ice has broken and the route has been opened", so the pilot of the second pulse will not go down step by step, but directly reach the ground from the cloud. This kind of pilot is called "direct channel pilot". After the direct pilot reaches the ground, it takes about a few thousandths of a second to counterattack and end the second pulse discharge process. Then the third and fourth ... straight lead and return strokes, completing multiple pulse discharge processes. Because each pulse discharge will consume a lot of accumulated charges in the thunderstorm cloud, the future main discharge process will become weaker and weaker, and the pulse discharge will not stop until the charge reserve in the thunderstorm cloud is exhausted, thus ending a lightning process.
When you read this article, there are about 1800 lightning exchanges going on all over the world. They emit about 600 lightning flashes per second, of which 100 hits the earth. Lightning can transform some nitrogen in the air into nitrogen compounds, which can be washed to the ground by rain. In a year, every hectare of land on the earth can get a few kilograms of this free fertilizer from the sky. Kampala, the capital of Uganda, and Java, Indonesia are the most vulnerable places to lightning strikes. According to statistics, there are 300 days of lightning in Java a year. The most violent lightning in history was that 1975 hit a small house near Umtali in rural Zimbabwe, when 2 1 person died.
The most common lightning is linear lightning, which is some very bright white, pink or light blue lines. It looks like a river with many branches on the map, and it hangs in the sky like a winding tree. Scientists have long known the "temper" of linear lightning. The whole process of linear lightning can be completely recorded by continuous high-speed camera, and the simulation experiment can be successfully carried out in the laboratory. lightning
In addition to linear lightning, there are spherical lightning and chain lightning, both of which are relatively rare. Spherical lightning often occurs in bad weather of strong thunderstorm. A fireball suddenly appeared in the sky after the linear lightning. Fireballs float around in the sky along winding paths, and sometimes they may stop and hang in the air. This kind of fireball likes to drill holes, and sometimes it rushes into the house through chimneys, windows and cracks in the door, and then slips out of the house. Compared with spherical lightning, chain lightning is more difficult to find. At present, people only know that it also appears after linear lightning and appears on the same path as linear lightning. It hangs in the sky like a row of luminous hammer balls, and slides slowly on the cloud curtain like a dotted line against the cloud. Lightning has a great influence on human activities, especially buildings and transmission lines, which may cause serious losses. The most practical way to protect buildings from lightning stroke is to install lightning arresters (lightning rods) to guide the electricity in lightning to a pre-selected safe area on the ground. Linear lightning, strip lightning, flake lightning, rocket lightning, ball lightning and bead lightning will all do harm to human beings, so you can't go out. What we usually see is linear lightning, just like a branch with many branches and twists and turns. Band lightning is similar to linear lightning, but the bright channel is wider and looks like a bright band. Spherical lightning usually occurs after linear lightning. It is a fireball with a diameter of about 20 cm, emitting red or orange light, and occasionally emitting beautiful green, usually lasting for several seconds. Fireballs drift in the air with the wind, like to slide along the edge of objects, and can enter the room through gaps. When they are about to disappear, there will be a deafening explosion. Among all kinds of lightning, the rarest is the combined bead lightning, which most people in the world have never seen. This kind of lightning is shaped like a string of glowing pearls extending from the cloud to the ground (1916 On May 8, 2006, bead lightning appeared over a bell tower in Dresden, Germany, and was recorded. People first saw a linear lightning falling from the cloud; Later, people saw that the channel of linear lightning widened and the color changed from white to yellow. Soon the lightning channel gradually darkened, but the whole channel did not darken evenly at the same time, so the bright channel became a string of pearl-like bright spots hanging on the clouds, which was beautiful and moving. It is estimated that there are 32 bright beads, each with a diameter of 5 meters. After that, the bright beads gradually shrink and become round in shape; Finally, the brightness gets darker and darker, and then it goes out completely. ) Because the probability of this kind of lightning is very small and its duration is very short, people have little research on the causes of this kind of lightning, and the reasons for its formation are still unclear.
Edit the type of lightning in this paragraph.
The difference between linear lightning and other lightning is that its current intensity is particularly large, reaching tens of thousands of amperes on average and 200,000 amperes in a few cases. Such a large current intensity will destroy and shake trees and sometimes hurt people. When it comes into contact with buildings, it often causes "lightning strike" and fire. Linear lightning is mostly cloud-to-ground discharge. Flake lightning Flake lightning is also a common lightning shape. It looks as if there is a flash of light on the cloud. This kind of lightning may be the background light of the invisible spark discharge behind the cloud, or the diffuse light generated by the lightning in the cloud being blocked by the cloud droplets, or it may be a cluster or flickering independent discharge phenomenon appearing in the upper part of the cloud. Spherical lightning Spherical lightning is a form of lightning, also known as spherical lightning, which is often called rolling thunder by the people. This is a very rare lightning shape, but it is the most striking. It is like a fireball, and sometimes it is like a luminous "hydrangea" chrysanthemum. It is about the size of a human head, and occasionally it is several meters or even dozens of meters in diameter. Spherical lightning sometimes swims slowly in the air, and sometimes it hangs completely still in the air. It sometimes emits white light, and sometimes it emits pink light like a meteor. Ball lightning likes to make holes. Sometimes, it can enter the house through chimneys, windows and cracks, turn around the house and then slip away. Spherical lightning sometimes hisses and then disappears with a muffled sound; Sometimes it just makes a faint crack and disappears unconsciously. After the ball lightning disappears, some unpleasant gas smoke may be left in the air, which is a bit like ozone. The average diameter of spherical lightning is 25 cm, most of them are between 10 and 100 cm, the smallest is only 0.5 cm, and the largest is several meters. Spherical lightning occasionally has a ring or blue halo extending outward from the center, emitting sparks or rays. Common colors are orange or red. When it appears with particularly bright glare, you can also see yellow, blue and green. Its life span is only 1 ~ 5 seconds, and it can reach several minutes at the longest. The walking route of spherical lightning generally falls directly from the sky, and suddenly changes direction and moves horizontally when approaching the ground; Some suddenly appear on the ground and bend forward; There are also those that roll along the surface and rotate rapidly; The speed of motion is often 1 ~ 2 meters per second. It can enter the building through doors and windows, usually through chimneys. It can even slide on the wire and sometimes make a "buzzing" sound. Most fireballs disappear silently, and some will explode when they disappear, which will cause damage and even collapse buildings, causing human and animal deaths. People will have an amazing explosion when they meet something, producing a pungent smell, causing casualties, fires and other accidents. The way to prevent ball lightning is to close doors and windows in thunderstorm weather to avoid direct flow. If you encounter a floating "fireball", avoid it gently and never touch it. Scientists speculate that spherical lightning is a gas vortex produced at the sharp turn of lightning path, which is a gas mixture with high charge, mainly composed of oxygen, nitrogen, hydrogen and a small amount of water. It usually happens after dendritic lightning, and it seems that dendritic lightning is a necessary condition to produce spherical lightning. Ball lightning is rare, so it is very difficult to study, and it is still a mystery in nature. Strip lightning consists of multiple continuous discharges. Between each lightning, due to the influence of the wind, the lightning path moves, making each individual lightning close to each other and forming a band. The belt width is about 10 meter. If this lightning strikes a house, it will immediately cause a large area to burn. Beaded lightning Beaded lightning looks like a connecting line that slides on the cloud curtain or throws it to the ground through the clouds, and it also looks like a sparkling pearl necklace. Some people think that bead lightning seems to be a transitional form from linear lightning to spherical lightning. Beaded lightning often follows linear lightning with almost no time interval. Rocket lightning rocket lightning is much slower than other kinds of lightning, and it takes L ~ 1.5 seconds to fully discharge. Its activities are easy to track and observe with the naked eye. Black lightning is usually blue, red or white, but sometimes there are black lightning. Due to the action of sunlight, cloud electric field and some physical and chemical factors in the atmosphere, a particle with very active chemical properties will be produced in the sky. Under the action of electromagnetic field, these particles gather together to form many spheres. This ball will not give off energy, but it can exist for a long time. It has no light and is opaque, so it can only be observed during the day.
Edit this paragraph of Super Lightning.
Super lightning refers to those rare lightning whose power exceeds ordinary lightning 100 times. The electricity generated by ordinary lightning is about 1 megawatt, while the electricity generated by super lightning is at least 1 megawatt, and may even reach trillions to 1 megawatt. Clock Island in Newfoundland was obviously struck by a super lightning at 1978. Even the houses at 13 km away rattled, and the windows and doors of the whole village were sprayed with blue flames.
Edit this paragraph of submarine lightning
There is also lightning at the bottom of the sea, which was discovered by scientists from the former Soviet Union at the bottom of Japan. Sensitive electric field instruments show that the frequency of submarine discharge is the same as that of lightning in the atmosphere, which puzzles scientists. Because according to the laws of hydrogeology, deep seawater has good conductivity, so it should be out of reach with Lei Gong Dian Mu. After repeated experiments, scientists finally believe that the charge source actually comes from the air on the land near the coast, and then travels through rocks all the way to the bottom of the sea. However, with the increase of conduction distance, the amount of electricity gradually decreases. Therefore, the flow measured on the seabed is generally weak.
Edit this black lightning.
Finally, there is a comfort: when you see lightning, it can't hit you. The formation of black lightning is beyond the explanation of scientists. For a long time, people's minds only have blue and white lightning, which is a natural phenomenon of atmospheric discharge in the air, usually accompanied by dazzling light! I've never seen "black lightning" that doesn't shine. But through long-term observation and research, scientists have indeed proved the existence of "Black Lightning". lightning
1On June 23rd, 974, chernov, an astronomer of the former Soviet Union, saw a "black lightning" in Zabarozh: at first it was a strong spherical lightning, and then a mass of black things flew behind, which looked like a foggy condensate. Research and analysis show that Black Lightning is produced by molecular aerogel aggregates, and these aggregates are hot and charged substances, which are easy to explode or transform into spherical lightning, which is extremely dangerous. According to observation and research, Black Lightning is generally not easy to appear near the ground. If it appears, it is easy to hit trees, masts, houses and other metals. Generally, it is a lump or a lump. At first glance, it looks like a dirty thing, which is easily overlooked by people, but it contains a lot of energy. Therefore, it is a lightning family with great danger and harm. In particular, Black Lightning is small and difficult to be captured by radar; And it is very "favored" for metal objects; Therefore, it is called "aerial dark mine" by pilots. If the plane touches black lightning during the flight, the consequences are unimaginable. Whenever black lightning is close to the ground, it is easy to be mistaken for a bird or something else, which is not easy to arouse people's vigilance and attention; If you hit with a stick, it will explode quickly, and there is a danger of breaking people into pieces. In addition, Black Lightning is similar to spherical lightning, and general lightning protection facilities, such as lightning rods, lightning balls and lightning nets, cannot protect Black Lightning; Therefore, it often reaches the vicinity of oil storage tanks, gas storage tanks, transformers and explosives depots with extremely strict lightning protection measures. Don't go near it at this moment. Should be avoided, focusing on personal safety. The cause of lightning formation red lightning
In thunderstorm clouds, due to the friction and decomposition of water molecules, the airflow will generate static electricity. There are two kinds of electricity. One is the positive charge of positively charged particles and the other is the negative charge of negatively charged particles. Positive and negative charges attract each other, just like magnets. The positive charge is at the top of the cloud, and the negative charge attracts the positive charge on the ground at the bottom of the cloud. The air between the cloud and the ground is an insulator. It will prevent the current of bipolar charge from passing through. When the charge in the thunderstorm cloud and the charge on the ground become strong enough, these two parts will break through the air barrier and contact to form a strong current, positive charge and negative charge contact. When these opposite charges meet, neutralization (discharge) will occur. Strong charge neutralization will release a lot of light and heat. These emitted lights form lightning. Most lightning strikes will happen twice in a row. The first time it was called lead flash, it was an invisible air that went down to a place close to the ground. This charged air is like a wire, which establishes a guide for the second current. At the moment when the conductor is close to the ground, a backflow jumps up along the conductor. The flash produced by this backflow is the lightning we can usually see.
Purple lightning
The lightning generated by a single cloud system near the ground and the earth is mostly blue-purple lightning, which is very thick and directly inserted into the ground, and its energy is extremely destructive. In the sky, lightning generated by two or more cloud systems is mostly bright white or reddish light.
In fact, lightning is a kind of arc discharge, which emits white light and contains a lot of ultraviolet rays, thus giving people a purple feeling, in which the color of light is only a part. Red mainly comes from the chemical changes of some gases in the air under the action of strong light, resulting in colored gases. Blue-white light is light with different wavelengths seen by naked eyes. When the cloud moves violently, the fire-that is, lightning-is very powerful, and it ionizes the air to produce purple light with short wave length and high energy. On the contrary, it is.
Edit the reason for the thunder in this paragraph.
Now we know that when the charge is neutralized, it will release a lot of light and heat, and instantly release a lot of heat, heating the surrounding air to a high temperature of 30,000℃. When a powerful current passes through the air, the air along the way will suddenly expand, and at the same time, it will push the surrounding air and make the air vibrate violently. The sound produced at this time is [thunder]. Don't forget to tell the baby that thunder and lightning happen at the same time, because the speed of light is much faster than the speed of sound. Therefore, we always see lightning first and then hear thunder. If lightning falls nearby, we will hear deafening thunder or tearing. If lightning falls in the distance, we will hear rumbling thunder. This is because sound waves are refracted by the atmosphere and reflected by ground objects. If lightning falls nearby, we will hear the sound of trees falling and then explode. This is because lightning quickly tears the air and then makes a tearing sound. What others see and think is a simple personal feedback on external things. The formation of lightning may be the fireworks of God or the product of dragons. The analysis of things focuses on details. Only by seeing the movement of molecules can we understand the structural changes of everything: "Baidu is advised to search for lightning in slow motion", and "the unity of man and nature" can be seen from the eyes of everyone: "The shape of human blood" winner "Lightning Strike"; Macro "the shape of the earth's blood vessels (rivers)" and "the shape of the earth's cracks" (or "the satellite remote sensing map of mountains"): nothing can be separated from its "sect"
Edit the necessary conditions for lightning to occur in this section.
1. The air should be very humid; 2. Clouds must be big and dark; Usually cumulonimbus clouds; 3. Lightning is not easy to happen in arid areas.
Edit this lightning and thunderstorm cloud
The atmospheric electric field in thunderstorm is obviously different from that in sunny days. The reason for this difference is the accumulation of charges in thunderstorm clouds, which forms the polarity of thunderstorm clouds, produces lightning and causes great changes in atmospheric electric field. But how does thunderstorm cloud get electricity? That is to say, what are the physical processes in the thunderstorm cloud that cause it to be charged? Why can so many charges accumulate in thunderstorm clouds and form a regular distribution? This section will answer these questions. As we said before, the macroscopic process of thunderstorm cloud formation and the microphysical process in thunderstorm cloud are closely related to cloud electrification. Scientists have made a lot of observations and experiments on the charging mechanism of thunderstorm clouds and the regular distribution of charges, accumulated a lot of data and put forward various explanations, some of which are still controversial. To sum up, there are several scientific hypotheses about the charging mechanism of clouds: A. For the "ion flow" hypothesis in the initial stage of convective clouds, there are always a lot of positive ions and negative ions in the atmosphere. On the water droplets in the cloud, the charge distribution is uneven: the outermost molecules are negatively charged, the inner layer is positively charged, and the potential difference between the inner layer and the outer layer is about 0.25 volts. In order to balance this potential difference, water droplets must "preferentially" absorb negative ions in the atmosphere, which makes water droplets gradually negatively charged. When the convection begins, the lighter positive ions are gradually carried to the upper part of the cloud by the updraft; However, the cloud droplets with negative charges remain in the lower part because they are relatively heavy, resulting in the separation of positive and negative charges. B. Charge accumulation in cold clouds When convection reaches a certain stage and the cloud reaches a height above 0℃, there are supercooled water droplets, graupel particles and ice crystals in the cloud. This cloud, which is composed of water vapor condensate with different phases and the temperature is lower than 0℃, is called Leng Yun. The process of charge formation and accumulation in Leng Yun is as follows: a. Ice crystals collide with graupel particles to generate electricity. Polonium particles are composed of frozen water droplets, which are white or milky white and have a brittle structure. Because supercooled water droplets often collide with it and release latent heat, its temperature is generally higher than that of ice crystals. Ice crystals contain a certain amount of free ions (OH- or H+), and the number of ions increases with the increase of temperature. Because of the temperature difference between the contact part of graupel and the ice crystal, the free ions at the high temperature end must be more than those at the low temperature end, so the ions must migrate from the high temperature end to the low temperature end. In the process of ion migration, the lighter positively charged hydrogen ions are faster, while the heavier negatively charged hydroxide ions (OH-) are slower. Therefore, in a certain period of time, the phenomenon of excess H+ ions at the cold end appeared, which led to negative polarization at the high temperature and positive polarization at the low temperature. When ice crystals come into contact with graupel particles and separate, the graupel particles with higher temperature are negatively charged, while the ice crystals with lower temperature are positively charged. Under the action of gravity and updraft, the lighter positively charged ice crystals are concentrated in the upper part of the cloud, while the heavier negatively charged haze particles stay in the lower part of the cloud, resulting in the Leng Yun being positively charged in the upper part and negatively charged in the lower part. B. supercooled water droplets collide with graupel particles to freeze and charge. There are many water droplets in the cloud that will not freeze when the temperature is below 0℃. This kind of water drop is called supercooled water drop. Supercooled water droplets are unstable. Just shake it a little and it will freeze into ice particles at once. When supercooled water droplets collide with graupel particles, they will freeze immediately, which is called collision freezing. When the collision occurs, the outside of the supercooled water droplets immediately freezes into an ice shell, but the inside of the supercooled water droplets temporarily remains liquid. Because the latent heat released by the external freezing is transferred to the inside, the temperature of the liquid supercooled water inside is higher than that of the external ice shell. The temperature difference makes the frozen supercooled water droplets positively charged outside and negatively charged inside. When the inside also freezes, the cloud drops expand and split, and the outer skin breaks into many small positively charged ice chips, which fly to the upper part of the cloud with the airflow. The core of the negatively charged frozen drops adheres to the heavier graupel particles, so that the graupel particles are negatively charged and stay in the middle and lower part of the cloud. C. Water drops are charged due to thin salt. In addition to the above two electrification mechanisms in Leng Yun, it has been suggested that the electrification mechanism is due to the thin salt contained in water droplets in the atmosphere. When the cloud drops freeze, the crystal lattice of ice can accommodate negative chloride ions (Cl-) but repel positive sodium ions (Na+). Therefore, the frozen part of water droplets is negatively charged, and the unfrozen outer surface is positively charged (water droplets are frozen from the inside out). In the process of falling, the graupel particles frozen by water drops fall off from the surface water before freezing, forming many small clouds with positive charges, while the frozen core is negatively charged. Due to the separation of gravity and airflow, positively charged water droplets are carried to the upper part of the cloud, while negatively charged polonium particles stay in the middle and lower part of the cloud. D. Charge accumulation of warm clouds Some main mechanisms of Leng Yun charging are mentioned above. In the tropics, some clouds are above 0℃, so they only contain water droplets and no solid water particles. This kind of cloud is called warm cloud or "water cloud". There will be lightning in warm clouds. In the thunderstorm clouds in the mid-latitude region, the part of the cloud below the 0℃ isotherm is the warm region of the cloud. There is also an electrification process in the warm area of the cloud. In the process of thunderstorm cloud development, the above mechanism may play a role in different development stages. However, the main electrification mechanism is still caused by the freezing of water droplets. A large number of observation facts show that only when the cloud top presents a fibrous filament structure can the cloud cluster develop into a thunderstorm cloud. Aircraft observation also found that there are a large number of cloud particles mainly composed of ice, snow crystals and graupel particles in thunderstorm clouds, and the accumulation of a large number of charges is the rapid charging mechanism of thunderstorm clouds, which can only occur through collision, freezing and friction during the growth of graupel particles.
Edit this paragraph why lightning and thunder don't happen at the same time.
Lightning and thunder occur at the same time, but their propagation speeds in the atmosphere are very different, so people always see lightning first and then hear thunder. Light can travel about 300 thousand kilometers per second, while sound can only travel 340 meters. According to this phenomenon, we can calculate the distance from when we see lightning to when we hear thunder. If lightning is in the northwest and thunder is heard every 10 second, it means that this thunderstorm is about 3400 meters away from us.
How far is lightning from us?
When lightning approaches, you hear a sharp crack; If lightning is far away, you hear a rumble. You can start the stopwatch after you see the lightning, press the stopwatch to stop when you hear the thunder, and then divide the number of seconds by 3 to get a rough idea of how many kilometers the lightning is from you. If the time difference is 3 seconds, the lightning is one kilometer away.