Conditions for tornado formation

The condition is that tornado is the strongest vortex phenomenon in the atmosphere, which often occurs in summer thunderstorm weather, especially in the afternoon and evening. Although the scope of influence is small, it is extremely destructive. Next, come with me to see how tornadoes are formed.

Conditions for the formation of tornadoes:

Tornadoes, a natural phenomenon, are the product of thunderstorms in clouds. Specifically, a tornado is a form in which a small part of the huge energy of a thunderstorm is released in a small area.

Cumulonimbus clouds that can produce tornadoes are all giant cumulonimbus clouds. In the process of cloud-sky discharge, the positive charge at the top of the cloud is much greater than the negative charge at the bottom of the cloud. After the cloud is neutralized by lightning, the negative charge at the cloud bottom is insufficient, and the cloud with a large number of positive charges forms a strong electric field with the ground. Under the action of electrostatic attraction, positively charged clouds protrude downward from the bottom of the clouds, and negatively charged air gathers from all around for electric neutralization. At the bottom of the cumulonimbus cloud, a funnel cloud appears first, and the surrounding air rotates at high speed.

If the positive charge in the cloud is large enough, the funnel cloud will quickly extend to the ground or water surface, and a tornado will form when it meets the surface. The cloud column of a tornado is a downward moving cloud airflow with a large number of positive charges. There is a strong electric field between the cloud column and the ground. Although the electric field is not enough to cause lightning, it can produce strong negative ion flow (electron flow) on the ground or water surface. Driven by the negative ion flow, the air rises rapidly, forming a low pressure area. Under the action of atmospheric pressure, the surrounding air converges to the center of low pressure, and the converged air accelerates to rise under the action of negative ion flow. The converging airflow is influenced by the earth's rotation bias. Tornadoes rotate counterclockwise in the northern hemisphere and clockwise in the southern hemisphere. The above air movement makes the pressure at the bottom of the tornado lower and lower and the wind speed stronger and stronger.

Characteristics of tornadoes:

Tornado is the strongest vortex phenomenon in the atmosphere, which often occurs in thunderstorm weather in summer, especially in the afternoon and evening. Although the scope of influence is small, it is extremely destructive. Tornadoes often pull up trees, overturn vehicles and destroy buildings where they pass. It often destroys crops and tens of thousands of fruit trees in an instant, disrupts traffic, collapses houses and loses human and animal lives. The horizontal range of tornadoes is very small, ranging from several meters to several hundred meters in diameter, with an average of about 250 meters and a maximum of about 1 km. The diameter in the air can be several kilometers, and the maximum is 10 kilometers. The maximum wind speed can reach 150 km to 450 km per hour, and the tornado usually lasts only a few minutes, but the longest is only a few minutes.

Types of tornadoes:

Vortex tornado

A tornado in which more than two whirlpools revolve around the same center. Multi-vortex structures often appear in violent tornadoes, and these small vortices often cause greater damage in the area where the main tornado passes.

tornado

Landspout and the National Weather Service called dust tube tornado a term to describe tornadoes unrelated to mesoscale cyclones. Tornadoes and waterspouts have some similar characteristics, such as relatively weak intensity and short duration, and funnel-shaped clouds formed by condensation often do not touch the ground. Although the intensity is relatively weak, tornadoes will still bring strong winds and serious damage.

outfall

Can be simply defined as. Water tornado? This usually means a non-supercell tornado on the water. The hose will overturn the ship and destroy it. When it lands, it will do more harm and take away life.

Dragon Suction is another name for tornado, because it is very similar to Donghai Dragon in ancient mythology, and it has many other names, such as? Dragon absorbs water? 、? The dragon wags its tail? 、? Inverted dragon? Wait a minute.

Tornadoes are water-absorbing dragons, which are common tornadoes on land. Tornadoes are the flow of air, and air is invisible. The air pressure in the center of the tornado is very attractive. Attract dust, water vapor and other sundries. Due to gravity, liquid water cannot stay in the air for a long time. After the dragon absorbs water, the water sucked into the sky will fall and form a rainstorm, so the so-called dragon suction is a tornado.

Dragon suction is a tornado that occasionally appears over warm water. Its upper end is connected with thunderstorm clouds, and its lower end extends directly to the water surface. The air spins rapidly around the axis of the tornado. Attracted by the extremely low air pressure in the center of the tornado, the water flow is sucked into the bottom of the vortex and then becomes a vortex around the axis.

Tornado commonly known as? Dragon absorbs water? It is a strong wind vortex with small range and strong wind force extending from the bottom of thunderstorm cloud to the ground or water surface.

Tornado winds are very strong. Near the tornado center, the horizontal wind speed can reach more than 100 meters per second, and in extreme cases it can reach 300 meters. 12 wind speed is equivalent to more than 30 meters per second, and the damage caused is amazing.

Tornado winds are very strong, mainly because a large amount of air escapes in the tornado, which makes the air in the center of the tornado very thin and the air pressure is very low, which is particularly different from the air pressure in the periphery. The air difference between the typhoon center and the periphery is 20 millibars per 100 km on average, while the air difference between the tornado center and the periphery is 20 millibars as long as it is 20 meters. The greater the pressure gradient, the greater the wind force. The wind force of a tornado is many times greater than that of a typhoon, but the area involved in a tornado is very small.

When a whirlwind appears in a river, lake or ocean, a tornado will form. When the cold air mass in the atmosphere passes through the water body, the warm and humid gas rises upward, forming a huge water column. When these water columns pass through the sea surface, they will leave traces of water vapor formation. The diameter of the water column varies from several feet to several hundred feet, and its length exceeds 1 mile (1.6 1 km), and it goes deep into the clouds. Tornadoes at sea are weaker than cyclones, and often only when they cross the land will they pose a threat to people.

Fire tornado

A very rare form of tornado, consisting of tornadoes and flames. The tornado rolled up a flame several meters high and spun like a giant fire dragon.

Appear? Fire dragon wind? The main reason is that the unusually dry weather and strong winds contributed to the fire here. The air dryness in Sao Paulo has caught up with the Sahara desert.

Fire whirlwind, also known as fire monster and fire whirlwind, refers to the rare phenomenon that when a fire occurs, the temperature and thermal gradient of the air meet certain conditions, and the flame forms a vertical vortex and inserts straight into the sky like a whirlwind. Rotating flames mostly occur in jungle fires. The height of the flame varies from 30 to 200 feet, and its duration is limited, usually only a few minutes, but if the wind is strong, it can last longer.

Gust rolling

It is a small vertical rotating airflow associated with gust front and downburst. Because they are not strictly related to clouds, it is still controversial whether they belong to tornadoes. When the fast-moving dry and cold airflow overflowed by thunderstorm flows through the static warm and wet airflow at the overflow edge, it will cause the rotation effect (available? Cirrus? If the low-level wind shear is strong enough, this rotation will be horizontal (or inclined) and affect the ground, and the final result will be gust. The rotation direction of gust coil is not fixed, which can be clockwise or counterclockwise.

dust whirl

Dust wind is a special rotating convection motion caused by uneven local heating on the ground. In the process of dust wind formation, the peripheral air flows to the center through the thin layer near the ground after being heated by the ground, and the rotating energy of the peripheral air is strengthened at the center to form dust wind. Its rotational energy is formed by the local concentration of the original rotational energy of the thermal convection bubble and the transformation of some potential energy, and its rotational direction is determined by the initial rotational direction of the thermal convection bubble.

It is worth noting that tornadoes are completely different from sandstorms. Tornadoes are the product of thunderstorms in the clouds. A small cyclone produced by the intense warming of the ground is characterized by rolling up the dust on the ground and forming a rotating dust column with light and small objects.