What level is the tornado? What is the speed of each level? Thank you very much

Tornadoes are not classified, only wind speed. The wind speed may be 50- 150 meters per second, and in extreme cases it may even reach 300 meters per second or exceed the speed of sound.

Feng Juan got its name because it is very similar to the East China Sea Dragon that jumped out of the waves in ancient mythology, and it has many aliases, such as "dragon absorbs water", "dragon wags its tail" and "upside down dragon".

Now we know that a tornado is a circular column of air that rotates violently. Its upper end is connected with thunderstorm clouds, its lower end is suspended in mid-air, and some directly extend to the ground or water surface, and move forward while rotating. It happens at sea, just like the phenomenon of "dragon absorbing water", which is called "waterspout"; Tornadoes that appear on land, roll up dust and take away houses, trees, etc. , known as the "land tornado". From a distance, it is not only like a huge python dangling in the air, but also like the nose of an elephant that keeps swinging.

How did this big "trunk" come into being?

Tornadoes in nature were born in thunderstorm clouds. In thunderstorm clouds, the air disturbance is very intense, and the temperature difference between the upper and lower parts is very large. On the ground, the temperature is more than 20 degrees Celsius. The higher the altitude, the lower the temperature. At the top of the cumulonimbus cloud at an altitude of more than 8 thousand meters, the temperature is as low as MINUS 30 degrees Celsius. In this way, the cold air above drops rapidly, and the hot air below rises violently. When the updraft reaches high altitude, if it encounters strong horizontal wind, it will force the updraft to "upside down" (rotate downward). Due to the alternating disturbance at high altitude, it rotates and forms many small eddies. These small eddies gradually expand. The agitation became stronger and stronger, and finally a large vortex was formed. The large vortex first rotates around the horizontal axis, forming a horizontal air rotating column. Then, the two ends of the air rotating column gradually bend and slowly hang down from the bottom of the cloud. For the direction of cumulonimbus clouds, the cloud extending from the left is called "left tornado" and the cloud extending from the right is called "right tornado"; The former rotates clockwise and the latter rotates counterclockwise. Generally, the right tornado reaches the ground, and the left tornado has little chance to reach down.

In addition, tornadoes are also prone to occur at the intersection of two squall lines. Squall lines often appear in the most "outpost" of strong cold air in hot seasons.

When there is a tornado, there is often more than one. Sometimes two or more "trunk" funnel cloud columns will appear in the same cumulonimbus cloud. Only some "trunk" has just started to extend downward, some "trunk" lower end has landed or is shrinking into the cloud after landing, and some stretch and contract at the bottom of the cloud and never land again.

Tornadoes have a small range, with an average diameter of 200-300 meters; The smallest diameter is only tens of meters, and only a few large diameters reach 1000 meters. Its life is also very short, often only a few minutes to dozens of minutes, no more than a few hours. Its average moving speed is15m per second, and the fastest speed can reach 70m. The length of the moving path is mostly around 10 km, the short path is only tens of meters, and the long path can reach hundreds of kilometers or more. The ground width caused by it is generally only l-2 kilometers.

Tornadoes are extremely grumpy. Wherever you go, the roar is like thunder, which is better than the low-flying fleet. This may be because the wind speed in some parts of the vortex exceeds the sound speed, resulting in a small amplitude shock wave. How competitive is the wind speed in a tornado? People can't measure it yet, because any anemometer can't stand its destruction. Generally speaking, the wind speed may be 50-150m per second, and in extreme cases it may even reach 300m per second or exceed the speed of sound.

Supersonic wind energy can generate infinite power. 1896, a pine stick carried by a tornado in St. Louis, USA, actually penetrated a steel plate with a thickness of one centimeter. 1 19 19 A tornado occurred in Dazhou, Minnis, USA, which made a thin grass stalk pierce a thick board. A clover leaf is deeply embedded in the mud wall like a wedge. However, the wind speed in the center of the tornado is very small or even windless, which is very similar to the situation in the eyes of a typhoon.

What is particularly frightening is the low pressure inside the tornado. The low pressure can be as low as 400 mbar or even 200 mbar, and the standard atmospheric pressure is 10 13 mbar. Therefore, the place swept by a tornado, like a special water pump, often sucks up the water, dust and trees it comes into contact with, forming a tall column, which is what people used to call "the dragon hangs upside down" or "the dragon sucks water". Yu Yu, Blood Rain, Grain Rain and Yuqian were formed by tornadoes that swept some colored substances or other substances on land and fish in the sea into the air, moved to a certain place, and fell to the ground with heavy rain.

When a tornado sweeps over the top of a building or vehicle, the building or vehicle will "explode" as soon as it leans because of its extremely low internal air pressure and strong air pressure difference between the inside and outside of the building or vehicle. If the tornado and the huge wind force together, the damage and loss will be extremely serious.

But under normal circumstances, when a tornado passes through a residential area, there will be fragments such as bricks and broken wood flying in the sky. Due to the high wind speed, people and animals will be killed and injured, and trees and telephone poles will be smashed into holes. Even pebbles, like bullets, can go through the glass without crushing it.

According to statistics, tornadoes have occurred in every land country, and the United States is the country with the most tornadoes. Canada, Mexico, Britain, Italy, Australia, New Zealand, Japan and India also have many opportunities for tornadoes. Tornadoes in China mainly occur in South China and East China, and they often appear in the Xisha Islands in the South China Sea.

Because the occurrence of tornadoes is closely related to the occurrence of strong thunderstorms, tornadoes generally appear in warm seasons. But in the cold season without thunderstorms, tornadoes may occur as long as there are strong convective conditions.

Tornadoes can occur during the day and at night, but most of them occur in the afternoon. Sometimes, several tornadoes appear together.

Tornadoes may also be caused by smoke and water vapor from volcanic eruptions and fires. This kind of tornado is called fire tornado or smoke tornado.

All kinds of tornadoes are small in scope and short in life, which brings great difficulties to scientific research and prediction. However, before the arrival of the tornado, as long as you pay attention to observation, there will always be some noteworthy weather phenomena and characteristics. For example, before the formation of a tornado, the atmosphere was unstable, the convection in the cloud system was strong, the air pressure was obviously reduced, and the cloud bottom was particularly turbulent, which was helpful for forecasting tornadoes. In addition, weather radar plays an important role in finding and tracking tornadoes. It can detect thunderclouds 300 kilometers away, and once the hook echo of a tornado is found in the radar, it can give an alarm. But when some tornadoes appear, this hook echo is not obvious. Therefore, the combination of radar and vision is often more reliable. When an observer finds a tornado, he should immediately report it to the meteorological department, which can track it by radar, and then give an alarm to the residents and units in the tornado path for a while.

The appearance of meteorological satellites has added new detection means for tornado forecasting, especially the cloud images taken by synchronous satellites, which have played a more important role in monitoring the occurrence of tornadoes. Satellites can observe day and night and can see smaller targets. If satellites are combined with radar, we can continuously observe the changes of tornadoes and give an early warning half an hour before tornadoes occur.