Now the wind speed measured by special devices - cup anemometer.This device is quite simple: on the vertical axis spinning a spider, which are placed at the ends of the hemisphere.These cups are able to grasp even the smallest whiff.Under the influence of his cross begins to rotate, and the recording device records the speed is the vertical axis.Thus, we can say that the wind was blowing at a speed of so many meters per second, or so many kilometers per hour.Next to the anemometer mounted vane, showing the direction of air flow.
But earlier, before the invention of precision instruments that determine wind speed, people used the scale, which was developed by the English Admiral Beaufort.He made the table where all the air jets are classified from zero to 12 points.For clarity, Beaufort used box: at zero (completely calm) banner hanging on the flagpole.At one Ballet moves slightly when the two - swaying, at three - waving, and so on, up to 12 points when the wind turns into a real hurricane, ripping off bridges and houses.It is understood that when the air flows are accelerated to a speed of 37 meters per second, to talk about the flag is no longer necessary: his tears and carries with flagpole element.
However, 12 points or 37 m / s - this is not the limit.Modern devices allow improved measurement of Beaufort and supplemented them with five more points.It Saffir-Simpson scale that measures a very strong blow.The wind speed in the hurricane, according to the Beaufort should not be less than 35 m / s, but in the tropics, and not only them, it happens that the air mass moving with a record speed of 170 meters per second.The strength of the movement at the same time is that simple straw stuck in a hard surface like iron nails!In order to determine these elements, bearing failure, human language came up with many names: cyclone, squall, tornado, a blood clot, storm, hurricane.One phenomenon or whether it is different?
Let us, to begin with, consider the power that claimed the house Alley in the magical land of Oz.United States of America at its western end are high and cold Rocky Mountains.Cold air over the mountains accumulates and forms a high-pressure area.The eastern United States horseshoe surrounding the Gulf of Mexico and the warm Caribbean Sea - an area of low pressure.Between the mountains and the ocean are vast, flat as a table top, open spaces of Kansas, Iowa and Oklahoma.Seeing no special obstacles, cold air rushes down to meet with thermal updrafts, spiraling.Thus was born the "tornado" ("spinning" in Spanish), or "clot" ("pipe" in French).The name is very apt: it is the phenomenon looks like a giant tube from earth to heaven, within which everything revolves.The wind speed at the same time in the middle of the tube can reach 150 m / s, while they themselves move over the surface of the pipe at a speed of 50-60 kilometers per hour.
Sometimes a warm air mass over the Caribbean and other seas tropical latitudes rampaging over the sea.Then they are called tropical cyclones (in Greek "kiklon" - ring snakes) or hurricanes (recast "Huracan" - so the inhabitants of the Antilles called "destroying all spirit").The wind speed at a huge hurricane, and the level of destruction - too.According to the "Coriolis force", because of the rotation of the Earth, in the southern hemisphere hurricane spiral twisted in a clockwise direction, and in the north - counterclockwise.Meteorologists call these elements, born in the northern hemisphere, female names, and in the south - male.Names are given to the Latin alphabet from the beginning of the year until December 31, for example, Alice, Bertha, Catherine, etc.It is necessary to calculate how many tropical cyclones were born during the year, and to compare these data with other years.Not all the squalls have caused such harm as "Katrina" New Orleans.But the measurement of wind speed, the pressure in the "eye of the storm" and the classification of the typhoon on the Saffir-Simpson scale will assess the level of imminent danger and to take measures to evacuate people.
