What is a tornado and what determines its appearance?
Fortunately, few of the inhabitants of our countryknows what a tornado is. Of course, we do not mean small twists, which sometimes appear in the fields and desert roads. We are talking about giant atmospheric vortices, which, 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 what has arisen because ofpressure difference, a huge air funnel that spins at an incredible speed and draws at the same time everything that happened to be in its center. In America, what is 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. Rotation inside such a vortex goes counter-clockwise, just as it does in the cyclones that occur in the northern hemisphere of our planet.
Vertically one such funnel can reachten, and on the vertical - 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. Nikolayevsky, 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 occurs in the form of a pipe, funnel or trunk, which hangs from the mother cloud. Take a look at the tornado, whose picture is shown below. It looks awesome, does not it?Sometimes the number of victims of such events reachesseveral 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?
A tornado is often formed on the troposphericfronts, where the boundaries of the division of air masses with different temperatures, speeds 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 wet 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 onlyon the lower, dusty water part, you can guess about the danger threatening the ship. 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 the appearance of tornadoes there is very high.