What is the origin of tornadoes?

Tornado is a kind of strong air cyclone with a small range, which is called tornado for short.

Although the tornado has a small range of activities and a short time, it is extremely destructive. It often

Trees were uprooted, houses were destroyed and people's lives were hurt.

Before the tornado formed, there was a strong air vortex above it, so that it could suck up the ground and water.

Things in the room.

During the development of thunderstorm clouds, the ground temperature is 20-30 degrees Celsius, and the temperature at the bottom of thunderstorm clouds drops to 10 degrees.

A few degrees, 4000 meters above sea level, the temperature dropped to 0 degrees, 8000 meters above sea level, as low as zero.

30-40 degrees. In this way, the cold air drops rapidly, while the hot air rises violently, and the upper and lower air move alternately.

Formed many small eddies. When these small eddies don't develop, they just stretch and contract at the bottom of the cloud.

When the small vortex gradually expands and stirs up and down badly, a large vortex is formed and extends to the ground.

There was a tornado. So tornadoes usually occur in summer, and the speed of tornadoes is often as high as 100 per second.

200 meters, even 200 meters, five to six times larger than the typhoon of 12. However, it has not created many opportunities.

The influence range is generally only tens or hundreds of meters wide, and the diameter of waterspout is usually only 20 to 100.

Rice; The lulongjuan is only 100 to 1000 meters. The average speed of tornado movement is 15 meters per second, all of which are straight lines.

It is not easy to make sharp turns when going straight.

Tornadoes occur in almost all areas of China, the most common being from the afternoon of March to the night of September.

Among them, June to September is the most.

cause

Tornado is a kind of strong wind vortex accompanied by a funnel-shaped cloud column rotating at high speed, which is produced by the strong convection movement of two air streams under extremely unstable weather conditions.

Tornadoes have a strange appearance. Its upper part is black or thick gray cumulonimbus clouds, and its lower part is a drooping funnel-shaped cloud column shaped like an elephant's nose. The wind speed is generally 50 meters per second to 100 meters, and sometimes it can reach 300 meters per second. Because the air inside the tornado is extremely thin, the temperature drops sharply and the water vapor condenses rapidly, which is also an important reason for the formation of funnel cloud column.

National situation

In Bangladesh, due to high population density, poor housing quality and poor knowledge of tornado safety, about 179 people die from tornadoes every year.

On average, there are 80 tornadoes in Canada every year, causing 2 deaths and 20 injuries and losing tens of millions of dollars. On July 4th, 2000, a "killer tornado" struck Songye Lake in Alberta, Canada, killing 1 1 people.

Britain is the most frequent tornado area in Europe. If you count the area of relevant land, Britain and the Netherlands are the countries that suffer the most tornadoes per unit area in the world, and the Netherlands can suffer an average of 0.00048 tornadoes per square kilometer every year. There are also small strong tornadoes in parts of New Zealand and Uruguay.

The United States suffers the most tornadoes in the world, with an average of 100000 thunderstorms and 1200 tornadoes every year, with 50 deaths. In the vast areas of the midwest and south of the United States, "tornado alley" is the most famous. The deadliest tornado on record in the United States occurred on March 1925, passing through tri-state tornadoes in southeastern Missouri, southern Illinois and northern Indiana, killing 695 people. [9]

2065438+02 [10] On March 2, Alabama and Tennessee in the southern United States were hit by tornadoes, and at least two tornadoes hit the northeastern part of the state that day. The two tornadoes hit Huntsville at about 9: 00 a.m. to 9: 30 a.m. local time, with an interval of about 10 minute. In Alabama, tornadoes damaged many houses, blew down many trees and injured at least four people.

In Capshaw, 0/6 km from Hunts Viljo/Kloc-,the state prison in Lemstone, Alabama was also damaged by a tornado. The prison is a maximum security prison, holding more than 265,438,000 prisoners, about 200 of whom are HIV-positive and are held in isolation.

Although Alabama prison was destroyed by a tornado, no prisoners escaped. Part of the outer wall of the prison and two prison houses were damaged, but the prison itself remained safe.

In addition to Alabama, Chattanooga, Tennessee was also hit by a tornado, injuring more than 20 people. The local Hamilton County Sheriff's Office confirmed that many local people were injured due to extreme weather, and the Bradley County Government also confirmed that houses were damaged.

A huge storm system is raging in the eastern, western and southern parts of the United States. This storm system has caused tornadoes in several states since February 28th, 20 12, and killed 13 people in Kansas, Missouri, Illinois and Tennessee.

On August 26th, 20 12, around 17∶30, a rare phenomenon of "dragon sucking water" appeared on Hongze Lake in Jiangsu, China, and a huge water column connected the water surface with the sky. The gray water column hangs down the lake from the dark clouds in the distance, hanging precariously in the air like a python. At this time,

Water absorption phenomenon of Hongze Lake Dragon in Jiangsu Province

You can still see blue sky and white clouds in the sky, and the dark clouds dragging the water column are particularly conspicuous. Master Liu said that he has lived in Hongze Lake for more than ten years and has never seen dragons absorb water.

20 13 On the afternoon of May 20th, local time, Moore, a suburb of Oklahoma, the capital of central Oklahoma, was hit by a strong tornado on the afternoon of the 20th, killing at least 9/kloc-0 people and injuring 233 others. The square tower primary school in this area was razed to the ground, and 24 children were trapped in the ruins.