Recently, the topic of positive lightning has attracted many people's attention. Many people think that lightning is lightning, and there are no types, but in fact, lightning is also divided into many types. One of the types of lightning is positive lightning. So what's the difference between positive lightning and negative lightning? What are the types of lightning? This article brings you a detailed introduction. Let's have a look.
What is the difference between positive lightning and negative lightning
lightning
Lightning is generally two kinds. One comes from between two clouds. One cloud is positively charged and the other is negatively charged. Form positive and negative discharge. The other is heaven and earth thunder (that is, the kind that kills people). Clouds are positively charged (positive), and the earth is negatively charged (negative).
Charged thunderstorm clouds are usually positively charged in the upper layer and negatively charged in the lower layer. Due to charge induction, the ground under the clouds is positively charged, so an electric field of millions of volts is formed between heaven and earth. Air is a bad conductor of electricity, so the positive charge of the ground moves upward along trees, mountains, tall buildings and people, combined with the negative charge of clouds.
At the same time, the negative charge of the clouds is also emitted to the ground. Each launch, the closer it is to the ground. Finally, overcome the air resistance and the positive and negative electricity meet. Along a conductive air channel, a large number of positive charges rush from the ground to the clouds, and then burst into dazzling light. Ordinary lightning has a temperature of 30000 to 50000 degrees Fahrenheit, which is equivalent to three to five times the surface temperature of the sun. Some lightning lasts a little longer, about 0.1 seconds, and some only 0.001 seconds.
Storm clouds usually generate electric charges, with negative electricity at the bottom and positive electricity at the top. Moreover, they also generate positive charges on the ground and follow the clouds. Positive and negative charges attract each other, but air is not a good conductor. Yang electricity runs to the top of trees, hills, tall buildings and even the human body, trying to meet the clouds with Yin electricity; The negative charge branched antennae extend downward, and the more they extend downward, the closer they are to the ground. Finally, the Yin and Yang charges finally overcome the air barrier and connected. A huge current surged from the ground to the clouds along a conduction airway, producing a bright flash. The length of a lightning bolt may be only thousands of meters, but it can be up to hundreds of kilometers.
The temperature of lightning varies from 17000 degrees Celsius to 28000 degrees Celsius, which is equal to 3 ~ 5 times the surface temperature of the sun. The extreme heat of lightning makes the air expand violently along the way. The air moves rapidly, so it forms waves and makes sound. When the lightning is close, what you hear is a sharp crack; If you are far away, you hear a rumble. You can start the stopwatch after seeing the lightning, press it to stop when you hear the thunder, and then divide the seconds by 3 to roughly know that the lightning is thousands of meters away from you.
What are the types of lightning
lightning
Ordinary lightning with twists and turns is called branch lightning. If the channel of branch lightning is blown to both sides by the wind, so that there appear to be several parallel lightning, it is called ribbon lightning. If two branches of lightning appear to reach the ground at the same time, they are called forked lightning.
When lightning flashes between the Yin and Yang charges in the cloud and brightens the sky all over the region, it is called flake lightning.
Lightning that does not reach the ground, that is, lightning in the same cloud or between two clouds, is called cloud lightning. Sometimes this kind of horizontal lightning will walk a distance and land on the ground many kilometers away from the storm, which is called a 'bolt from the blue'.
The electric action of lightning sometimes forms a halo of red light around tall, pointed objects. Usually on the sea in a storm, a fiery red light can be seen around the mast of a ship. People borrow the name of the seaman's patron saint and call this lightning 'the fire of St. Elmo'.
Super lightning refers to rare lightning that is more than 100 times more powerful than ordinary lightning. The power generated by ordinary lightning is about 1 billion watts, while the power generated by super lightning is at least 100 billion watts, and may even reach trillion to 100000 billion watts.
In 1978, clock island in Newfoundland was obviously attacked by a super lightning. Even houses 13 kilometers away were rattled, and the doors and windows of the whole countryside were spewing blue flames.
Lightning activity law
lightning
(1) Geological conditions: when the relative value of soil resistivity is small, it is conducive to the rapid accumulation of charges. Places with small local resistivity are vulnerable to lightning strikes; Sudden change of resistivity and underground conductive mineral deposits are easy to be struck by lightning; In fact, the resistivity of grounding grid will increase the probability of lightning stroke.
(2) Topographic conditions: the trend of the valley is consistent with the wind direction, and the tuyere or downwind Valley is vulnerable to lightning stroke; The slopes of mountains close to lakes and seas are more likely to be struck by lightning.
(3) Ground conditions: it is conducive to establish a good discharge channel between thunderstorm clouds and the earth. Isolated buildings in open areas and tall buildings in buildings are vulnerable to lightning strikes; Trees, receiving antennas and transmission lines in mountainous areas are vulnerable to lightning strikes; In line with the characteristics of tip discharge, the probability of lightning stroke will also be increased after the completion of the base station tower.
2. According to engineering experience, the following places may be places with high probability of lightning damage.
(1) Where there is a sudden change in soil resistivity R10 at 10m depth.
(2) At the junction of stone mountain, paddy field and river, the boundary of mineral resources, the boundary of mountain forest, and some geological fault zones.
(3) Mountain Yueyang slope or windward slope facing vast water area.
(4) High, isolated peaks.
(5) Locations where lightning disasters have occurred repeatedly in the past.
(6) Near isolated towers and stay wires, high-rise buildings and other grounding protection devices.