Traditional Culture Encyclopedia - Weather forecast - How do tornadoes form? What is the specific principle?

How do tornadoes form? What is the specific principle?

First, the reasons for the formation of tornadoes

Because the small-scale air vortex is caused by the strong convective movement of the air under unstable weather conditions.

Tornadoes are caused by unstable mesoscale airflow, with an average diameter of 200-300 meters, the smallest is only tens of meters, and only a few large ones reach 1000 meters or more.

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 generally1~ 2km.

Second, the principle of tornado formation

1, the instability of the atmosphere produces a strong updraft, which is further strengthened due to the influence of the maximum transit airflow in the rapids.

2. Due to the interaction with the wind with shear speed and direction in the vertical direction, the updraft begins to rotate in the middle of the troposphere, forming a mesoscale cyclone.

3. With the development and upward extension of mesoscale cyclone to the ground, it becomes thinner and stronger. At the same time, the strengthening of cooperation in a small area, that is, the primary tornado formed inside the cyclone, forms the tornado core.

4. The rotation in the tornado core is different from that in the cyclone, and its intensity is enough to make the tornado extend all the way to the ground. When the developing vortex reaches the ground, the ground air pressure drops sharply and the ground wind speed rises sharply, forming a tornado.

Extended data

There are many tornadoes in America:

Tornadoes in the United States are not only numerous, but also strong, so they are called "the hometown of tornadoes". This is mainly related to the geographical location, climatic conditions and atmospheric circulation characteristics of the United States. The United States faces the Atlantic Ocean in the east, the Pacific Ocean in the west and the Gulf of Mexico in the south. A large number of water vapor continuously flows from the east, west and south to the United States.

The United States is mainly located in the mid-latitude, and it is often controlled by subtropical high in spring and summer, and even affected by its edge in autumn and winter. The south and west of the subtropical high are the most active places in the east and southeast, and it is a sufficient condition for the formation of thunderstorm clouds to continuously transport a large amount of warm and humid air from the Atlantic Ocean and the Gulf of Mexico to the United States. Thunderstorm clouds continue to develop strongly, and tornadoes follow.

Baidu encyclopedia-tornado