What is a tornado and what determines its appearance?

Fortunately, few people from our country know what a tornado is. Of course, we do not mean small twists that sometimes appear in fields and desert roads. We are talking about giant atmospheric vortices that, as a rule, appear in a thundercloud and descend almost to the earth's surface in the form of a trunk or a cloudy sleeve with a diameter of several tens, or even hundreds of meters. Despite the fact that they do not last long, many troubles can be expected from them. Let's consider in more detail what kind of phenomenon it is.

What is a tornado?

Try to imagine the huge air funnel that has arisen because of the difference in pressure, which rotates at an incredible speed and draws into it everything that happened to be nearby. In America, about what a tornado, many know firsthand. There it is customary to call this phenomenon a tornado. There are also synonyms: meso-hurricane and thrombus, but they are used much less often. The rotation inside such a vortex goes counter-clockwise, just as it does in the cyclones that arise in the northern hemisphere of our planet.

Whirlwind characteristics

Vertically one such funnel can reach ten, and vertically fifty kilometers. The wind speed in it often exceeds 33 m / s. Talking about what a tornado, it must be noted that he has incredible power. According to the estimates of such experts as A. Yu. Gubar, SA Arsen'ev and V. N. Nikolaevsky, the energy of an average tornado with a radius of one kilometer and a velocity of about 70 m / s is comparable to the energy of the atomic bomb tested by the United States in July 1945 in New Mexico. In their form, tornadoes are not only in the form of funnels. Sometimes a tornado resembles a barrel, a cone, a glass, a biciform rope, a column, the horns of the devil, an hourglass , etc. But most often it appears in the form of a pipe, funnel or trunk, which hangs from the parent cloud. Take a look at the tornado, the photograph of which is presented below. It looks awesome, does not it? Sometimes the number of victims of such phenomena reaches several hundred people. The most terrible and famous tornado in the history of America is Tristate. Flown on March 18, 1925 across three states (Missouri, Illinois, Indiana), he took 747 human lives with him ...

Where does the tornado appear and what causes it?

The tornado is often formed on the tropospheric fronts, where the interfaces of air masses with different temperatures, velocities and humidity of air pass. In the zone of collision of cold and warm fronts, the atmosphere is extremely unstable and promotes the birth of a tornado in the mother cloud, and below several smaller turbulent vortices. Most often it happens in the autumn and spring-summer period. For example, cold fronts separate dry and cold air from Canada from damp and warm air from the Atlantic Ocean or the Gulf of Mexico. Sometimes such a collision occurs over the sea surface, and then a sea whirlwind appears. It can be almost completely transparent and only on the lower, dusty water part, you can guess about the threatening vessel danger. The tornado is not only on Earth, but also on other planets of our system, for example, on Jupiter and Neptune. On Mars, a tornado can not appear due to low pressure and too rarefied atmosphere. But on Venus the situation is exactly the opposite, and therefore the probability of tornadoes there is very high.